Periodontal Disease Assessing the Effectiveness and Costs of the

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					                                                                               CASE S11JDY _5
Periodontal Disease: Assessing the
Effectiveness and Costs of the Keyes
             Technique                        THE IMPLICATIONS OF

             May 1981
                                           ANALYSIS OF
       NTIS order #PB81-221780         MEDICAL TECHNOLOGY

                                       BACKGROUND PAPER #2: CASE STUDIES OF
                                             MEDICAL TECHNOLOGIES

                                       CASE STUDY _5: PERIODONTAL DISEASE: ASSESSING THE
                                        eFFECTIVeNESS AND COSTS OF THE KEYES TECHNIQUE
                                                                                 CASE   STUDY # 5

                        THE IMPLICATIONS OF
          ANALYSIS OF
                                          MAY 1981

  C A S E S T U D Y #5: P E R I O D O N T A L       DISEASE:         ASSESSING          THE
   EFFECTIVENESS             AND      COSTS      OF    THE     KEYES       TECHNIQUE

                                  Richard M. Scheffler, Ph. D.
                       Visiting Associate Professor of Health Economics
                   School of Public Health, University of California, Berkeley
                                Sheldon Rovin, D. D. S., M.S.
                       Chairperson, Department of Dental Care Systems
            School of Dental Medicine, University of Pennsylvania, Philadelphia, Pa.
With commentary edited by: Allan J. Formicola, D. D. S., Dean, School of Dental and Oral Surgery,
                                Columbia University, New York

      OTA Background Papers are documents that contain information believed to be
      useful to various parties. The information undergirds formal OTA assessments or is
      an outcome of internal exploratory planning and evaluation. The material is usually
      not of immediate policy interest such as is contained in an OTA Report or Technical
      Memorandum, nor does it present options for Congress to consider.
Library of Congress Catalog Card Number 80-600161

      For sale by the Superintendent of Documents,
U.S. Government Printing Office, Washington, D.C. 20402

     This case study is one of 17 studies comprising Background Paper #2 for OTA’s
assessment, The Implication of Cost-Effectiveness Analysis of Medical Technology.
That assessment analyzes the feasibility, implications, and value of using cost-effec-
tiveness and cost-benefit analysis (CEA/CBA) in health care decisionmaking. The ma-
jor, policy-oriented report of the assessment was published in August 1980. In addition
to Background Paper #2, there are four other background papers being published in
conjunction with the assessment: 1 ) a document which addresses methodological
issues and reviews the CEA/CBA literature, published in September 1980; 2) a case
study of the efficacy and cost-effectiveness of psychotherapy, published in October
1980; 3) a case study of four common diagnostic X-ray procedures, to be published in
summer 1981; and 4) a review of international experience in managing medical tech-
nology, published in October 1980. Another related report was published in
September of 1979: A Review of Selected Federal Vaccine and Immunization Policies.
     The case studies in Background Paper #2: Case Studies of Medical Technologies
are being published individually. They were commissioned by OTA both to provide
information on the specific technologies and to gain lessons that could be applied to
the broader policy aspects of the use of CEA/CBA. Several of the studies were specifi-
cally requested by the Senate Committee on Finance.
    Because of particular circumstances regarding this case study on interventions for
periodontal disease, a commentary by a group of dental scientists and clinicians is
presented immediately folIowing the case study. The case study authors’ response is
presented after the commentary.
     Drafts of each case study were reviewed by OTA staff; by members of the ad-
visory panel to the overall assessment, chaired by Dr. John Hogness; by members of
the Health Program Advisory Committee, chaired by Dr. Frederick Robbins; and by
numerous other experts in clinical medicine, health policy, Government, and econom-
ics. We are grateful for their assistance. However, responsibility for the case studies re-
mains with the authors.


Advisory Panel on The Implications of
Cost= Effectiveness Analysis of Medical Technology

                        John R, Hogness, Panel Chairman
                President, Association of Academic Health Centers

Stuart H. Altman                                         Sheldon Leonard
  Dean                                                     Manager
  Florence Heller School                                   Regulatory Affairs
  Brandeis University                                      General Electric Co.

James L. Bennington                                      Barbara J. McNeil
  Chairman                                                 Department of Radiology
  Department of Anatomic Pathology and                     Peter Bent Brigham Hospital
    Clinical Laboratories
  Children Hospital of San Francisco                     Robert H. Moser
                                                           Executive Vice President
John D. Chase                                              American College of Physicians
  Associate Dean for Clinical Affairs
  University of Washington School of Medicine            Frederick Mosteller
Joseph Fletcher                                            Department of Biostatistics
   Visiting Scholar                                        Harvard University
   Medical Ethics
   School of Medicine                                    Robert M. Sigmond
   University of Virginia                                  Advisor on Hospital Affairs
                                                           Blue Cross and Blue Shield Associations
Clark C. Havighurst
  Professor of Law                                       Jane Sisk Willems
  School of Law                                             VA Scholar
  Duke University                                           Veterans Administration
OTA Staff for Background Paper #2

                                    Joyce C. Lashof, Assistant Director, OTA
                                        Health and Life Sciences Division

                                    H. David Banta, Health Program Manager

                                       Clyde J. Behney, Project Director
                                          Kerry Britten Kemp, * Editor
                                      Virginia Cwalina, Research Assistant
                                        Shirley Ann Gayheart, Secretary
                                          Nancy L. Kenney, Secretary
                                       Martha Finney, * Assistant Editor

                                           Other Contributing Staff

                            Bryan R. Luce    Lawrence Miike    Michael A. Riddiough
                                        Leonard Saxe    Chester Strobel*

OTA Publishing Staff

                                       John C. Holmes, Publishing Officer
                              John Bergling*    Kathie S. Boss  Debra M. Datcher
                               Patricia A. Dyson*    Mary Harvey*    Joe Henson

q OTA contract personnel.

   This case study is one of 17 that comprise                             q   examples with sufficient evaluable litera-
Background Paper #2 to the OTA project on the                                  ture.
Implications of Cost-Effectiveness Analysis of                        On the basis of these criteria and recommen-
Medical Technology. * The overall project was                       dations by panel members and other experts,
requested by the Senate Committee on Labor                          OTA staff selected the other case studies. These
and Human Resources. In all, 19 case studies of                     16 plus the respiratory therapy case study re-
technological applications were commissioned                        quested by the Finance Committee make up the
as part of that project. Three of the 19 were spe-                  17 studies in this background paper.
cifically requested by the Senate Committee on
Finance: psychotherapy, which was issued sepa-                         All case studies were commissioned by OTA
rately as Background Paper #3; diagnostic X-                        and performed under contract by experts in aca-
ray, which will be issued as Background Paper                       demia. They are authored studies. OTA sub-
#5; and respiratory therapies, which will be in-                    jected each case study to an extensive review
cluded as part of this series. The other 16 case                    process. Initial drafts of cases were reviewed by
studies were selected by OTA staff.                                 OTA staff and by members of the advisory
                                                                    panel to the project. Comments were provided
   In order to select those 16 case studies, OTA,                   to authors, along with OTA’s suggestions for
in consultation with the advisory panel to the                      revisions. Subsequent drafts were sent by OTA
overall project, developed a set of selection                       to numerous experts for review and comment.
criteria. Those criteria were designed to ensure                    Each case was seen by at least 20, and some by
that as a group the case studies would provide:                     40 or more, outside reviewers. These reviewers
   q   examples of types of technologies by func-                   were from relevant Government agencies, pro-
       tion (preventive, diagnostic, therapeutic,                   fessional societies, consumer and public interest
       and rehabilitative);                                         groups, medical practice, and academic med-
   q   examples of types of technologies by physi-                  icine. Academicians such as economists and de-
       cal nature (drugs, devices, and procedures);                 cision analysts also reviewed the cases. In all,
   q   examples of technologies in different stages                 over 400 separate individuals or organizations
       of development and diffusion (new, emerg-                    reviewed one or more case studies. Although all
       ing, and established);                                       these reviewers cannot be acknowledged indi-
   q   examples from different areas of medicine                    vidually, OTA is very grateful for their com-
       (such as general medical practice, pedi-                     ments and advice. In addition, the authors of
       atrics, radiology, and surgery);                             the case studies themselves often sent drafts to
   q   examples addressing medical problems that                    reviewers and incorporated their comments.
       are important because of their high fre-
       quency or significant impacts (such as
   q   examples of technologies with associated
       high costs either because of high volume
       (for low-cost technologies) or high individ-
       ual costs;                                                    :I
   q   examples that could provide informative
       material relating to the broader policy and
       methodological issues of cost-effectiveness
       or cost-benefit analysis (CEA/CBA); and

   q Office of Technology Assessment, U.S. Congress, The lmplica-
tions of Cost-Effectiveness Analysis of Medical Technology, GPO
stock No. 052-003 -00765-7 (Washington, D. C.: U.S. Government
Printing Office, August 1980).

                                                      tive. The reader is encouraged to read this study
       studies on gastrointestinal endoscopy and      in the context of the overall assessment’s objec-
       on the Keyes technique for periodontal dis-    tives in order to gain a feeling for the potential
       ease, commentaries from experts in the ap-     role that CEA/CBA can or cannot play in health
       propriate health care specialty have been      care and to better understand the difficulties and
       included, followed by responses from the       complexities involved in applying CEA/CBA to
       authors.                                       specific medical technologies.
   The case studies were selected and designed to       The 17 case studies comprising Background
fulfill two functions. The first, and primary,        Paper #2 (short titles) and their authors are:
purpose was to provide OTA with specific in-
formation that could be used in formulating           Artificial Heart:, Deborah P. Lubeck and John P.
general conclusions regarding the feasibility and       Bunker
implications of applying CEA/CBA in health            Automated Multichannel Chemistry Analyzers:
care. By examining the 19 cases as a group and          Milton C. Weinstein and Laurie A. Pearlman
looking for common problems or strengths in           Bone Marrow Transplants: Stuart O. Schweitz-
the techniques of CEA/CBA, OTA was able to              er and C. C. Scalzi
better analyze the potential contribution that        Breast Cancer Surgery: Karen Schachter and
these techniques might make to the management           Duncan Neuhauser
of medical technologies and health care costs         Cardiac Radionuclide Imaging: William B.
and quality. The second function of the cases           Stason and Eric Fortess
was to provide useful information on the spe-         Cervical Cancer Screening: Bryan R. Luce
cific technologies covered. However, this was         Cimetidine and Peptic Ulcer Disease: Harvey V.
not the major intent of the cases, and they             Fineberg and Laurie A, Pearlman
should not be regarded as complete and defini-        Colon Cancer Screening: David M. Eddy
tive studies of the individual technologies. In       CT Scanning: Judith L. Wagner
many instances, the case studies do represent ex-     Elective Hysterectomy: Carol Korenbrot, Ann
cellent reviews of the literature pertaining to the     B. Flood, Michael Higgins, Noralou Roos,
specific technologies and as much can stand on          and John P. Bunker
their own as a useful contribution to the field. In   End-Stage Renal Disease: Richard A. Rettig
general, through, the design and the funding          Gastrointestinal Endoscopy: Jonathan A. Show-
levels of these case studies was such that they         stack and Steven A. Schroeder
should be read primarily in the context of the        Neonatal Intensive Care: Peter Budetti, Peggy
overall OTA project on CEA/CBA in health                McManus, Nancy Barrand, and Lu Ann
care.                                                   Heinen
                                                      Nurse Practitioners: Lauren LeRoy and Sharon
   Some of the case studies are formal CEAS or
CBAS; most are not. Some are primarily con-
                                                      Orthopedic Joint Prosthetic Implants: Judith D.
cerned with analysis of costs; others are more
                                                        Bentkover and Philip G. Drew
concerned with analysis of efficacy or effec-
                                                      Periodontal Disease Interventions: Richard M.
tiveness. Some, such as the study on end-stage
                                                        Scheffler and Sheldon Rovin
renal disease, examine the role that formal
                                                      Selected Respiratory Therapies: Richard M.
analysis of costs and benefits can play in policy
                                                        Scheffler and Morgan Delaney
formulation. Others, such as the one on breast
cancer surgery, illustrate how influences other         These studies will be available for sale by the
than costs can determine the patterns of use of a     Superintendent of Documents, U.S. Govern-
technology. In other words, each looks at eval-       ment Printing Office, Washington, D.C. 20402.
uation of the costs and the benefits of medical       Call OTA’s Publishing Office (224-8996) for
technologies from a slightly different perspec-       availability and ordering information.

                                                                               Case Study #5
                      Periodontal Disease: Assessing
                               the Effectiveness and Costs
                                    of the Keyes Technique

                                                            Richard M. Scheffler, Ph. D.
                                    Visiting Associate Professor of Health Economics*
                                                                School of Public Health
                                                       University of California, Berkeley
                                                           Sheldon Rovin, D. D. S., M.S.
                                       Chairperson, Department of Dental Care Systems
                                                            School of Dental Medicine
                                                            University of Pennsylvania
                                                                      Philadelphia, Pa.

             The authors would like to take this opportunity to thank the following individ-
        uals and organizations for their helpful suggestions on the earlier drafts of our report:
        Dr. John F. Goggins, National Institute for Dental Research, National Institutes of
        Health; Drs. Sigmund Socransky, J. Max Goodson, and Anne Tanner, Forsyth Dental
        Center; Dr. Phillip Canon, Beth Israel Hospital; the staff of the National Center for
        Health Services Research, Department of Health and Human Resources; and the staff
        of Division of Dentistry, Department of Health and Human Resources.

*On leave from Department of Economics, George Washington University, Washington, D.C.

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . ,
Periodontal Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       q            

Traditional Technologies Used To TreatPeriodontal Disease. . . . . .
    Nonsurgical Technologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
    Surgical Technologies . . . . . . . . . . . . . . . . . . . . . . . ........0
The Keyes Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
New Evidence on the Effectiveness and Cost of the Keyes Technique
   Data Collection. . . . . . . . . . . . . . . . . . . . . . * * . . * * . * * * . * * *

   The Effectiveness of the Keyes Technique . . . . . . . . . . . . . . . . .
   The Delivery and Cost of the Keyes Technique. . . . . . . . . . . . .
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * * * . * * . . . . * * .

Appendix A: Glossary of Dental Terms . . . . . . . . . . . . . . . . . . . . . . * * * * * * * * *
Appendix B: Questionnaire Used To Collect Data . . . . . . . . . . . . . .                          q              

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    q            

Commentary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      q   .****,            q      

Authors’ Response to Commentary . . . . . . . . . . . . . . . . . . . . . . . . .




     Periodontal Disease
                                                                                        Case Study #5:
                                       Periodontal Disease: Assessing
                                          the Effectiveness and Costs
                                               of the Keyes Technique

                                                                                  Richard M. Scheffler, Ph. D.
                                                           Visiting Associate Professor of Health Economics
                                                                                      School of Public Health
                                                                             University of California, Berkeley
                                                                                 Sheldon Rovin, D. D. S., M.S.
                                                             Chairperson, Department of Dental Care Systems
                                                                                  School of Dental Medicine
                                                                                  University of Pennsylvania
                                                                                            Philadelphia, Pa.

   Of the $13.3 billion spent on dental care in
1978, approximately $350 million was spent on
treating periodontal disease (10,12). About $250
million of this was received by periodontists
(dentists who specialize in treating periodontal
disease); the remaining $100 million was re-
ceived by general dental practitioners who de-
livered periodontal services. ’
  A significant portion of expenditures for peri-
odontal disease is for periodontal surgery. Such
surgery can be quite expensive. Two types of
periodontal surgery, mucogingival (gum) sur-
gery and osseous (bone) surgery, for example,
per quadrant of the mouth often cost the patient

   ‘The $100 million estimate for general practitioners was derived
by multiplying national expenditures on dental care ($13.3 billion)
(12) by 0.78 percent, which is the percentage of total expenditures
collected by general dentists for periodontal services (10). The esti-
mate of $250 million received by periodontists was derived by add-
ing the average income of periodontists, $56,741, to the average
expenses for all dental practices, $56,303 (3) for 1976 and adjusting
for inflationary increases of 6 percent per year to express it in 1978
dollars. This sum ($126,144) was then multiplied by the approx-
imately 2,000 periodontists practicing in 1978.

peroxide and baking soda and in some cases             tistical Area (SMSA) that use the Keyes tech-
drugs), and assessment of bacterial control by         nique. With data on 190 patients and over 800
regular microscopic examination of material            dental visits, we provide a short-term assess-
from the periodontal tissues. It involves the use      ment of the effectiveness of the Keyes technique
of water irrigation of the gums and other easily       and estimate the cost of delivering the Keyes
learned hygiene procedures. Some claim that, if        technique to the patients in our study. The re-
properly used, the Keyes technique could reduce        sults of our study provide new and useful data
dramatically the quantity of peridontal sur-           on the Keyes technique, but larger scale and
gery performed.                                        long-term studies are needed before more defini-
                                                       tive conclusions can be drawn.
   In the next three parts of this case study, we
present layman’s definitions of periodontal dis-          The final part of this study contains a brief
ease; a description of the technologies currently      sum mar y of some of our major conclusions.
being used on a widespread basis to prevent and        Also discussed are a few of the steps that need to
treat periodontal disease and an assessment of         be taken in order to allow a complete cost-effec-
what is known about their effectiveness, based         tiveness analysis (CEA) of the Keyes technique.
on a review of the literature: and a description       We did not perform a CEA of the current tech-
of the Keyes rationale and how it may be used          nologies used for treating periodontal disease,
for diagnosing, controlling, and preventin g           and no such analysis is available in the pub-
periodontal disease.                                   lished literature. Hence, we are unable to com-
                                                       pare the cost effectiveness of the Keyes tech-
  Next, we present some preliminary results of
                                                       nique to the cost effectiveness of the current
our recent study on 18 dental practices in the
                                                       treatment of periodontal disease.
Washington, D. C., Standard Metropolitan Sta-

    Tooth loss, in contrast to popular opinion            One of the difficulties in dealing with peri-
and mythology, is not a natural concomitant of         odontal disease is its insidiousness. The onset of
age—it is caused by disease processes. The dis-        disease is gradual. Afflicted individuals are gen-
ease processes of the periodontal, or supporting,      erally symptomless for long periods of time.
structures of the teeth, known collectively as         Often patients have extensive disease, involving
“periodontal disease” or “periodontal infec-           the loss of supporting structures and formation
t i on,” are responsible for 70 percent of all tooth   of deep pockets around the teeth, without being
extraction and are the principal cause of tooth        uncomfortable or even aware of the problem.
loss (6,13,15,33).                                     All too often patients will have undiagnosed
                                                       periodontal disease for years even though they
   Data show that some form of periodontal dis-
                                                       have been regularly seen by a dentist.
ease affects anywhere from 75 percent to vir-
tually all of the adult population in the United          The reasons for undiagnosed periodontal dis-
States, and a destructive form involving tissue        ease are several. Many dentists concentrate only
loss affects approximately one-third of the adult      on restorative problems of the teeth and thus ig-
population (6, 15,16,22,29). Periodontal disease       nore or fail to recognize periodontal disease un-
does afflict children, but it is more common and       til it has progressed to an advanced stage. The
more severe among adults. Although the disease         diagnosis of early or incipient periodontal
increases in prevalence and severity with age, it      disease requires not only visual inspection, but
is not the aging process that causes it; rather, it    probing, staining for plaque, and radiographic
is the length of time that the teeth and sup-          (X-ray) diagnosis; typical symptoms such as bad
portive tissues are exposed to the causative fac-      breath, spontaneous bleeding, and pain tend to
tors (21 ).                                            occur only after the disease has progressed to
                                      Case Study #5: Periodontal Disease: Assessing the Effectivenedd and Costs of the Keyes Technique q 5

the moderate or advanced stage. Furthermore,                            determine at a given point in time whether the
some dentists may not have been adequately                              destructive process is active or quiescent is cur-
trained in diagnosing and treating periodontal                          rently available (14), a circumstance with sig-
disease.                                                                nificant therapeutic implications.
   As is the case with many other chronic dis-
                                                                           Experientially, most dentists feel that the pro-
eases, early diagnosis of periodontal disease af-
                                                                        gression of gingivitis to periodontitis is part of a
fords a better chance for successful treatment. If
                                                                        continuum (25), i.e., if gingivitis persists long
disease is detected early, therapy requires less
                                                                        enough, it will inevitably progress into peri-
time and effort by the dentist, less discomfort to
                                                                        odontitis. However, there is no documented sci-
the patient during therapy, less difficult oral
                                                                        entific evidence for this view. It is known that
hygiene measures by the patient, and consider-
                                                                        periodontitis does not develop in the absence of
ably less cost. Moreover, the destructive form
                                                                        gingivitis (25); and it does appear that, in most
of periodontal disease first goes through a rela-
tively innocuous inflammatory stage, and, if di-                        instances, untreated gingivitis will progress into
                                                                        periodontitis (25). At the same time, there is
agnosed and treated at that time, the disease is
in most instances easily reversible. The univer-                        great variability in the time it takes for progres-
sality of periodontal disease is the most vexing                        sion to occur (gingivitis per se may exist for
                                                                        many years); and in some instances, progression
part of the problem, because in over 90 percent
of instances, such disease is potentially prevent-                      does not occur at all (8,25). The distinction be-
                                                                        tween gingivitis and periodontitis is empha-
able by relatively inexpensive means known and
                                                                        sized, because gingivitis, by far the most com-
available today (13,28,29).
                                                                        mon form of periodontal disease, is relatively
   Periodontal disease is a disease complex, a                          innocuous. Most important, it is potentially
group of diseases placed under a single heading                         reversible in a majority of instances. Uncom-
for purposes of convention. The term “peri-                             plicated by any other factor, gingivitis is usually
odontal disease” is generally used to refer to                          relatively easy to treat with methods that pro-
what are by far the two most prevalent peri-                            duce little or no discomfort to patients, and the
odontal diseases: gingivitis and periodontitis.                         cost of treating gingivitis is a small portion of
Gingivitis is inflammation of the gingiva (gum)                         what it costs to treat destructive periodontitis.
only and is generally considered a reversible
process (8). Periodontitis is inflammation of                              Bacteria] infection is the essential factor in the
both the gum and the other supporting struc-                            initiation and propagation of periodontal dis-
tures of the teeth (i. e., the outer bone of the                        ease (30,32). The exact mechanisms by which
tooth socket, the outer layer (cementum) of the                         the germs produce their deleterious effects re-
root of the tooth, and the soft tissues which at-                       main undiscovered, but there is little doubt that
tach these structures to one another). Periodon-                        bacteria are the principal cause of periodontal
titis also connotes destruction or loss of the sup-                     disease. The sine qua non in the etiology of peri-
porting structures of the teeth. Once destruction                       odontal disease is the presence of a microbial
takes place, complete regeneration of the af-                           population in the form of dental (or bacterial)
fected tissues does not occur (8). The l0SS or                          plaque. Dental plaque is a gummy bacterial sub-
destruction of the supporting structures results                        stance that adheres to the teeth; it cannot be
in the formation of pathologic spaces or pockets                        seen by the naked eye, but is easily demon-
around the teeth. 5 If this process continues, the                      strated by various stains. In the absence of
 teeth lose their supporting structure, become                          bacterial plaque, periodontal disease does not
loose, and eventually have to be removed. Un-                           occur; removal of such plaque halts the progres-
fortunately, no accepted diagnostic method to                           sion of, produces remission of, or reverses ex-
                                                                        isting disease. Further evidence of the role of
                                                                        bacteria in causing periodontal disease is the
     The normal space between the gum and the tooth is called a
SUlCUS. When this space deepens or extends past its normal bound-       fact that antimicrobial agents are often effective
ary as a result of the inflammatory process, it is called a pocket.     in controlling such disease (25,32).
6 q Background Paper #2: Case Studies   of   Medical Technologies

   Bacterial populations in the mouth differ                        margins actually initiate or just worsen the dis-
under conditions of health and of disease, a                        ease process. In either case, improper margins
finding which has also has therapeutic implica-                     have to be dealt with as a part of treatment.
tions (13). Furthermore, the same evidence
                                                                       There are other factors allegedly associated,
points to differences in the microbial composi-
                                                                    causally, with periodontal disease. A list would
tion of gingivitis and periodontitis. The im-
                                                                    include, in no relative order of importance,
portance of the role of bacteria in causing perio-
                                                                    malocclusion (malpositioning of the jaws with
dontal disease must be emphasized, because the
                                                                    respect to one another), faulty tooth position,
fundamental aim of periodontal treatment is to
                                                                    genetic predisposition, systemic disease such as
control bacterial plaque or to facilitate its con-
                                                                    diabetes mellitus, and malnutrition. No further
trol by the patient, and the principal goal of
                                                                    discussion about these factors is warranted,
prevention is to inhibit its formation.
                                                                    since they are not thought to be essential in
   Faulty or improperly placed margins of dental                    causing periodontal disease, and at most are
restorations (fillings) are recognized as a factor                  considered adjunctive to periodontal disease
contributing to periodontal disease (21,29). In                     (i.e., they might exacerbate preexisting peri-
the face of these margins, plaque accumulates                       odontal disease) (21,25,34). Also, the considera-
readily, and the existing inflammatory process                      tion of these factors in a CEA of periodontal
is enhanced. What is not clear is whether faulty                    therapy would be negligible.

  The traditional technologies used to treat                        remove it. Professionally supervised practice of
periodontal disease can be placed into two                          these techniques is usually a basic part of peri-
broad general categories—nonsurgical and                            odontal therapy. The outcome of periodontal
surgical.                                                           therapy depends on how well the patient con-
                                                                    trols plaque formation. In the absence of plaque
Nonsurgical Technologies                                            control, any therapy is of little or no value
Plaque Control
   There is a well-documented, direct relation-                        On the basis of the prevalence of periodontal
ship between the frequency of plaque removal                        disease (6,16,22), it appears that, unfortunately,
and gingival and periodontal health (5,29,31).                      most people do not effectively control plaque
Daily plaque removal is considered optimally                        formation, including many who have had exten-
conducive to gingival health. Obviously, indi-                      sive instruction and have been treated for de-
  .* *                                                              structive periodontal disease. The issue is not
viduals cannot have dental care professionals
remove plaque every clay. Patients must learn to                    simple. Plaque control is more than a question
remove plaque by themselves, a task not ter-                        of instruction about the proper methods. It re-
ribly onerous, but requiring some knowledge                         quires individuals to change or modify their be-
and mastery of technique.                                           havior so they not only know the correct meth-
                                                                    ods, but are motivated to use them routinely.
  The plaque control programs of periodontal
therapy are aimed at instructing patients in the
                                                                    Scaling and Root Planing
oral hygiene techniques that will remove plaque
and prevent it from accumulating in harmful                           Scaling and root planing are professionally
amounts. Basically, these oral hygiene tech-                        applied mechanical techniques. Scaling is used
niques are the application of stain to detect                       to remove calculus (hard deposits) from the
plaque and the brushing and flossing of teeth to                    teeth, root planing to smooth the root surfaces,
                             Case Study #s: Periodontal Disease: Assessing the Effectiveness and Costs of the Keyes Technique q 7

ostensibly to make the roots less susceptible to               Correcting Margins of Restorations
microbial activity. The largest proportion of the
                                                                  Since improper margins of dental restorations
time and effort expended in treating patients
                                                               contribute either to the initiation or severity of
with periodontal disease is devoted to scaling
                                                               periodontal disease, the correction of such mar-
and root planing (11). In some instances, sur-
                                                               gins is an integral part of therapy. The most im-
gical techniques are used to make the roots more
                                                               portant reason for correcting improper margins
accessible to this type of instrumentation.
                                                               is to facilitate plaque control, because in the face
   Although it is generally assumed that the gin-              of an overhanging restoration, for example,
giva are irritated by the mere physical presence               plaque removal is exceedingly difficult. Gener-
of calculus, this assumption awaits substantia-                ally, correction in the form of reducing bulk or
tion by scientific data (9). The microbial plaque              smoothing is done at the time of scaling and
covering the calculus is the noxious agent. Re-                root planing; but it is a requirement of peri-
moval of gross or obvious calculus appears to                  odontal therapy regardless of when it is done.
be indicated; however, what is not clear is
whether it is worthwhile to spend the time and                 Chemotherapy
effort required to remove small amounts of cal-
                                                                  Substantiation of the fact that micro-orga-
culus that are difficult to detect, particularly
                                                               nisms are a primary causative factor in peri-
since plaque re-forms in 24 to 36 hours (19,29).
                                                               odontal disease has sparked much interest in
  There is also disagreement about the benefits                chemotherapeutic control measures (1,20,29,
of root planing. The little evidence available                 30). Some of the initial attempts to control peri-
suggests that the primary rationale for root                   odontal disease with certain antimicrobial
planing is to remove calculus; root smoothness                 agents have been successful, but these attempts
may be inconsequential in retarding plaque for-                must be considered only trials. Essentially, in-
mation (11,29). At any rate, the most important                sufficient evidence is available to warrant the
determinant of periodontal health is the degree                routine use of these agents (29). Furthermore, a
to which patients exercise plaque control                      limitation of the studies thus far conducted is
(23,27,29).                                                    that they have been short-term. Periodontal
                                                               disease is of long duration and requires what
  Another issue relates to the frequency of pro-
                                                               amounts to a lifetime of effort in controlling
phylaxis (professional scaling) required to main-
                                                               plaque formation; an antimicrobial agent may
tain periodontal health. A landmark study indi-
                                                               suppress bacteria or reduce plaque formation in
cates that the optimal frequency is at 2-week in-
                                                               a short-term clinical trial, but this does not
tervals (5). However, other data suggest that
                                                               mean that it will do so effectively and safely,
quarterly intervals are also beneficial, although
                                                               without side-effects, for a long period of time.
not as effective as 2-week intervals (29). Again,
                                                               Nonetheless, further chemotherapeutic experi-
the benefits of scaling are believed to be less im-
                                                               mentation is warranted. However, at this time,
portant than the patient’s personal oral hygiene
                                                               chemotherapy is not considered a primary tech-
and plaque control. Unfortunately, more people
                                                               nology in the control of plaque or periodontal
rely on the dentist or hygienist for prophylaxes
than practice good plaque control themselves.
Thus, the issue of frequency must be examined,
particularly from a standpoint of cost effective-                 ‘Chemotherapy, the use of chemical agents—in this case antibi-
ness. On the basis of available evidence, pro-                 otics—to treat disease, is not an accepted, routine part of peri-
                                                               odontal therapy. It is included here because the role of micro-orga-
phylaxis at 2-week intervals would be cost pro-                nisms in causing periodontal disease has been shown only recently,
hibitive for most individuals. Moreover, given                 and the principal method of treating microbial diseases generally is
current methods of dental practice, there is in-               with these agents. As specific bacteria are identified as causative
                                                               agents, much more emphasis is likely to be placed on the use of
adequate manpower to routinely clean people’s                  chemotherapy. The discussion of chemotherapy is also included
teeth at 2-week intervals.                                     because of cost implications.
8 q Background   paper #.?:   Case Studies of Medical Technologies

Surgical Technologies                                                studies have been carried out, objective meas-
                                                                     urements of surgical effectiveness must remain
   Periodontal surgery, in one form or another,
                                                                     tentative at best.
is a common procedure used to eliminate the
pockets that occur in destructive periodontal                           Those studies that have been done do not
disease (24). Different surgical techniques are                      unequivocally point to one technique’s being
used for different purposes. Eliminating pock-                       superior to another (7,23,24,27). Moreover, al-
ets, making root surfaces more accessible to re-                     though the reasons for doing periodontal sur-
moving plaque, inducing reattachment of tis-                         gery can be supported experientially, scientific
sues, and restoring destroyed tissues are the                        evidence does not show that any of these sur-
main clinical objectives of employing these tech-                    gical techniques alone is effective in prolonging
niques (7). In practice, two or more techniques                      the life of the teeth. Periodontal surgery makes
often are used together to achieve a specific                        no difference in the absence of reasonable oral
result.                                                              hygiene by patients combined with professional
                                                                     maintenance (23,24,26,27). The surgery by itself
   Regardless of the objective of the specific sur-
                                                                     will not restore health to diseased periodontal
gical method, the fundamental rationale of peri-
odontal surgery is to prolong the functional life
of the teeth. The ultimate success or failure of                       In summary, we conclude that there is consid-
the particular surgical method, therefore,                           erable controversy surrounding the efficacy of
should be judged by the extent to which the                          the various surgical techniques used in the treat-
method conserves tooth life. Unfortunately,                          ment of periodontal disease. It is also fair to
there are few baseline data on which to make                         note that the emphasis on surgical technology
objective evaluations. With only a few excep-                        may be misplaced (29) and the type of surgery
tions (7,23,24), the studies of the different                        that is performed is considered far less impor-
surgical methods are short term. Longitudinal                        tant than whether or not the teeth can be main-
studies (longer than 5 to 10 years) required of                      tained in a state of good oral hygiene (4,23,24,
diseases having the apparent chronicity of peri-                     26,27).
odontal disease are needed. Until such scientific

   Dr. Paul Keyes and associates have developed                      vate him or her to help in its remediation. Oral
and are testing a technology they believe sup-                       hygiene and plaque control instruction is given
presses plaque microbes and arrests, or marked-                      in a slow, stepwise fashion over a 3- to 4-week
ly abates, the progression of destructive peri-                      period. Patients are also advised to rinse their
odontal disease (17,18). This technology in-                         mouths after eating, whenever possible, and to
volves the use of a meticulous diagnostic and                        use a pulsed-water irrigation device, such as a
therapeutic regimen, the latter involving the ap-                    Water Pik, once a day.
plication of certain salt solutions in all in-
stances, and periodic courses of systemic anti-                         Earlier we stated that there is no diagnostic
biotics when indicated. Therapeutic regimens                         method available to determine whether or not
are based on microscopic sampling of plaque in                       destructive periodontal disease is in an active
the pocket areas as a means of monitoring bac-                       state. The Keyes method purports to distinguish
terial activity. An integral part of the Keyes pro-                  active from inactive disease by assessing the
gram is to show the patient the actual bacteri-                      specific microbial population and inflammatory
ologic activity in the periodontal tissues though                    process in the pocket area. Dr. Keyes asserts
a microscope, the intent being to convince the                       what others believe but are not willing to assert
patient of the extent of the problem and to moti-                    without more substantiating evidence—that the
                              Case Study #.5: Periodontal Disease: Assessing the Effectiveness and Costs of the Keyes Technique q 9

specific bacteria identified via the microscope                 ditional technologies for treating periodontal
are predictors of pathologic status and that the                disease. The “traditional” technology is shown
bacteria associated with disease differ from                    in the lower half of the figure and the steps are
those found in healthy periodontal tissues. With                labeled by capital letters. The “Keyes” technol-
the information obtained via microscopic exam-                  ogy is shown in the upper half of the figure, with
ination, treatment is initiated which is aimed at               the steps labeled by lower case letters.
suppressing the microbial population and facili-
                                                                   Regardless of which technique will be applied
tating the patient in controlling plaque forma-
                                                                to an individual patient, all patients—those who
                                                                will be managed traditionally as well as those
   Although the Keyes method is still in the early              who will not—initially go through about the
stages of being tested, Keyes has reported                      same diagnostic and treatment planning proce-
marked improvement in patients he has treated                   dures. Once periodontal disease is diagnosed
(18). It should be emphasized that the effec-                   (Aa), patients can be treated either by “tradi-
tiveness of the Keyes method, like that of other                tional” methods or the “Keyes” method. At this
treatments, depends on the patient’s assiduously                juncture, all patients with periodontal disease
following the prescribed plaque control pro-                    receive oral hygiene instruction and extensive
gram (18). If it turns out that the Keyes method                tooth cleaning (scaling and root planing), see (B)
is as effective as its developers believe, then that            and (b) on the figure. A comparison of (B) and
would mean, among other things, that the pa-                    (b) shows that the patients being treated by the
tients using the Keyes method are doing a better                Keyes method also receive a microscopic exam-
job of controlling plaque than they would with                  ination and are placed on a regimen that in-
other technologies. That in itself would be a                   cludes salt-solution therapy.
most significant outcome.
                                                                   In patients being treated by the “traditional”
   Many individuals do not practice good oral                   method, a determination is then made of the
hygiene. Even patients who have undergone ex-                   presence or absence of pockets (C). If there are
tensive periodontal surgery and have received                   no pockets but disease is present (D), the patient
intensive oral hygiene instruction as a part of                 receives further tooth cleaning and hygiene in-
therapy often do not exercise adequate plaque                   struction (B). If pockets are present, some form
contro; the recurrence rate of periodontal dis-                 of surgery is usually, but not always, performed
ease in such patients is high (24). If the Keyes                (E). After surgery, if disease persists or recurs
method proves more effective than others, that                  (D), the patient receives additional tooth clean-
will mean that something about this method                      ing and hygiene instruction (B). If no pockets
enables or makes it easier for patients to exercise             are present and the patient is in reasonable oral
plaque control better than the other methods                    health (F), a maintenance phase is begun (G).
used to date. It could be the Keyes method’s                       In patients being treated by the “Keyes” meth-
slow, stepwise fashion of patient instruction.
                                                                od, by contrast, oral hygiene instruction and
Possibly, showing patients microbes taken from
                                                                bacteriologic monitoring continue (c), but there
their tissues under a microscope impresses the
                                                                is no surgery. If disease (d) persists, the patient
nature of the problem upon the patients in a
                                                                is generally placed for 2 weeks on a regimen of
more effective manner. This is only speculation,
                                                                antibiotics, 7 and oral hygiene instruction, mi-
and, of course, it is far too soon to tell if the
                                                                croscopic examination, and tooth cleaning are
Keyes technique has lasting effect. Much more
                                                                continued (b). If the patient is in reasonable oral
evaluation—particularly long-term evaluation
                                                                health (f), a maintenance phase is begun (g).
—is needed. (In the next part of this case study,
we present the first systematic assessment of the                  The Keyes technology differs from the tradi-
effectiveness of the Keyes technique in multiple                tional method of treating periodontal disease in
practice sites. )                                               three essential ways: 1 ) Microscopic diagnosis
   Figure 1 shows some of the important similar-                  ‘Antibiotics may also be used in the traditional method, but are
ities and differences between the Keyes and tra-                not used as routinely.

            I    No periodontal
                                                                 I                                      *
                                                                              1   (f)
                                                                                                    q   *


and monitoring of microbial activity is the basis      in figure 1 are general, and some of the par-
for therapeutic decisions; 2) salt solutions are       ticular steps may differ, especially in the “tradi-
used routinely and antibiotics are used often;         tional” technology. These differences or changes
and 3) periodontal surgery to eliminate pockets        depend on several factors, such as extent of dis-
is used infrequently, since complete pocket elim-      ease, the patient’s overall health, the patient’s
ination is not a goal of the Keyes method. The         ability or willingness to pay, and the personal
Keyes method is founded on Keyes’ belief that          treatment philosophy of the practitioner. Also,
halting the progression of the destructive proc-       it should be reemphasized that the ultimate suc-
ess and allowing natural healing to occur does         cess of therapy, regardless of method, depends
not depend on surgical elimination of the pock-        more on how well the patient practices good
et, but does depend on controlling bacterial           oral hygiene than on what the dentist does for
activity.                                              the patient.
  It should be emphasized that the steps shown
Data Collection
  To perform our study of the effectiveness and                        data for our estimates were collected on 190 pa-
cost of the Keyes technique, we collected data in                      tients and over 800 dental visits. Approximately
1979 on 18 dental practices from the Washing-                          63 percent of the patients were female. The aver-
ton, D. C., SMSA that currently use this tech-                         age age of all patients was 42.
nique. 8 Using written questionnaires, we col-
lected data on each practice and on a selection of                     The Effectiveness of
the patients in each practice who are currently                        the Keyes Technique
being treated with the Keyes technique. ’
                                                                          In order to demonstrate the effectiveness or
   Data on 8 of the practices were obtained via a                      lack of effectiveness of the Keyes technology,
mail survey, and data on the other 10 were col-                        five measures were used as general indicators of
lected by dental students. ’” All 18 of the dental                     periodontal disease of the patients in the study
practices surveyed were owned and operated by                          before and after treatment. All five oral health
solo general practitioners. The average age of                         indicators showed some improvement following
these practitioners was 47. The average length                         treatment (see table 1).
of time they had been in practice was almost 12
years; they had used the Keyes technique for                             A number of the important indicators
13.7 months on the average.                                            changed dramatically. Bleeding of gums upon
                                                                       probing, an indication of early or beginning
   Using information from the patients’ records,                       disease, dropped from 99 percent of the patients
we completed a written questionnaire on about                          showing it before treatment to 34 percent of the
10 patients in each practice who were beyond                           patients showing it at the time the information
their initial visit for the Keyes technique. 11 The                    was obtained. Another important change was
questionnaire used to collect data on individual                       the decrease from 65 to 9 percent in the number
patients is reproduced in appendix B. Using this                       of patients with loose teeth. This change is im-
questionaire, we obtained data relating to the
patient’s oral health status before treatment and                              Table 1 .—Periodontal Disease Indicators:
at the time the questionnaire was administered.                                 Effectiveness or Lack of Effectiveness
Data were also obtained on the services deliv-                                           of the Keyes Technique
ered to the patient during the first six visits and                                                                   Percentage of patients
the maintenance visit, on who delivered these
services, and in what amount of time. The                                                                                  before    Current
charges for each visit were also recorded. Usable                      Indicator                                         treatment   status
                                                                       1. Bleeding on probing . . . . . . . . . . .          99%      34%
                                                                                                                           N = 185   N = 185
   ‘Currently, there are 26 dental practices using the Keyes tech-     2. Suppuration. . . . . . . . . . . . . . . . . . 56            23
nique in the Washington, D. C., SMSA. Except for the data col-
                                                                                                                           N = 185   N = 181
lected at the National Institutes of Health by Keyes on his own
                                                                       3. Mobile teeth. . . . . . . . . . . . . . . . . . 65            9
practice, no other data of this type are currently available.
                                                                                                                           N = 178   N = 173
   “The data collection for the study was supported in part by a       4. WBCS microscopically evident . . 9 4                         78
grant (grant No. H.S.-O2577) from the National Health Care Man-                                                            N = 182   N = 172
agement Center, Wharton School, University of Pennsylvania.
                                                                       5. Motile forms microscopically
That center IS funded by the National Center for Health Services          evident . . . . . . . . . . . . . . . . . . . . . . 62       32
Research, Office of the Assistant Secretary for Health, Department                                                         N = 170   N = 148
ofHealth and Human Services.
   IOA comparison of the data collected via mail and the data COl-
lected by the dental students did not show any important statistical
differences. The data collected by the dental students were more
   "In some practices, we were able to complete questionnaires on
more than 10 patients; in others, we had to settle for fewer.
I2 q Background paper #2 Case Studies of Medical Technologies

portant because loose teeth are an indication of                            The Delivery and Cost of
advanced disease, A “t” test on the difference                              the Keyes Technique
between the percentages before and after treat-
ment for each of the periodontal disease indi-                                 The Keyes technique involves the delivery of
cators in table 1 was statistically significant at                          10 basic procedures. These procedures and the
the 0.01 level. Thus, these data indicate a sig-                            percentage of patients in our study population
nificant overall improvement in dental health                               receiving them during each visit to the dentist
for our study population.                                                   are shown in table 3. The first visit usually in-
                                                                            volves a dental history (76 percent) and a med-
   Moreover, at the time our study was done, 65                             ical history (84 percent). If histories are not pro-
percent of the 190 patients in the study popula-                            vided during this visit, that usually indicates
tion had gone from treatment to maintenance,                                that histories were provided at a visit prior to
and only 35 percent required further treatment.                             beginning the Keyes technique. This is also the
We also performed an analysis of the data over                              case for radiographs and visual assessment.
time. This analysis included some of the patients                           During the first visit, over half the patients
being treated and then maintained by the Keyes                              undergo periodontal probing (7 I percent), a
method for more than 24 months. *2 In these pa-                             microscopic examination (64 percent), and a
tients, the indicators of oral health continued to                          scaling (52 percent). About two-fifths of the pa-
show almost the same level of improvement as                                tients receive periodontal pocket measurements
in patients treated and maintained for less time.                           (40 percent) and almost one-sixth (16 percent)
   Furthermore, our analysis of the data con-                               receive root planing. Almost two-thirds of the
cerning the effect of the Keyes technology on the                           patients (64 percent) also receive plaque control
level of plaque control exercised by the patients                           instruction during the first visit.
showed that improvement in plaque control had                                   The percentage of patients receiving dental
occurred to the same extent as improvement in                               histories, medical histories, and radiographs, as
the other indicators (see table 2). For example,                            expected, declines after the initial visit. Over the
before treatment 93 patients were judged to                                 next two visits (visits 2 and 3), the percentage of
have below-average plaque control, but at the                               patients receiving root planing and scaling in-
time our data were collected only 12 patients                               creases. Later visits continue the use of scaling
were rated in this manner. A chi square test                                and root planing, as well as plaque control in-
showed patient improvement in plaque control                                struction and probing. The maintenance visit
(as indicated by the before and after data in                               shows some increase in visual assessment, scal-
table 2) for all groups of patients to be statis-                           ing, pocket measurement, and microscopic ex-
tically significant at the 0.01 level or greater.                           aminations. Clearly, the maintenance visit (ex-
(This finding does not apply to the group of pa-                            cept for the histories, diagnosis, and plaque con-
tients who were above average in plaque control                             trol instruction) is somewhat similar to the ini-
before treatment. )                                                         tial visit in terms of the procedures performed.

                                                                              To estimate the cost of producing the Keyes
        The data used for this analysis are not presented in this discus-   technique, we began with data on the amount of
                                                                            dentist and hygienist time used during each visit
                                                                            (see table 4). The majority of this time is used to
             Table 2.—Plaque Control by Patients                            instruct the patient in plaque control and pro-
                                                                            vide maintenance. The first visit uses an average
                                            After treatment
                                                                            of 28 minutes of dentist time and 24 minutes of
Patient status                       Above                     Below
 before treatment                   average      Average      average       hygienist time. ’3 For later visits (visits 5 and 6,
Above average (2). . . . . . . .       2             0            0           13
                                                                                 lt is interesting to note that the estimate of the average dentist
Average (76). . , . . . . . . . . . 56              19            1
                                                                            time has a large standard deviation in comparison to the mean (co-
Below average (93). . . . . . . 42                  39           12
                                                                            efficient of variation). A further analysis of the data showed that
  Total (171). . . . . . . . . . . . 100            58           13         there was a significant variation among the 18 dental practices, as
                                                                            well as across the patients treated within each practice.
                                               Case Study #5: Periodontal Disease: Assessing the Effectiveness and Costs of the Keyes Technique q 13

                              Table 3.—Mix of Services Delivered at Each Visit for the Keyes Technique

                                                                                     Percentage of patients (N)
Service                                                   Visit 1   Visit 2       Visit 3            Visit 4    Visit 5       Visit 6   visit
Dental history. . . . . . . . . . . . . . . . . . . .       76%         1 %          1 %               0          0             0         4%
                                                         N = 184    N = 177       N = 158       N = 135         N =99         N =69   N = 105
Medical history. . . . . . . . . . . . . . . . . . . 84                6                           6%             4%             1%
                                                         N = 184    N = 177       N =6158       N = 135         N =99         N =69   N 105
Radiographs. . . . . . . . . . . . . . . . . . . . . 71               10             7                            5             14       14
                                                         N = 184    N = 177       N = 158       N =7135        N = 100        N =69   N = 105
Visual assessment. . . . . . . . . . . . . . . . 97                   71            71            70             67            67        84
                                                         N = 184    N = 177       N = 158       N = 135        N =99          N =69   N = 105
Periodontal probing. . . . . . . . . . . . . . . 71                   62            60                           47            45        51
                                                         N = 185    N = 177       N = 158       N=99           N =99          N =69   N = 105
Pocket measurement . . . . . . . . . . . . . . 40                     20             17           14             12             19       32
                                                         N = 185    N = 177       N = 158       N = 135        N = 100        N =69   N = 105
Microscopic examination . . . . . . . . . . 64                        62            54            46             47            51        54
                                                         N = 185    N = 177       N = 158       N = 135        N =99          N =69   N = 104
Scaling . . . . . . . . . . . . . . . . . . . . . . . . . 52          63            66            62                           68        83
                                                         N = 184    N = 177       N = 158       N = 135        N =69          N =69   N = 105
Root planing . . . . . . . . . . . . . . . . . . . . . 16             33            35            28                           32        36
                                                         N = 185    N = 177       N = 158       N = 135        N =1OO         N =69   N = 105
Plaque control instruction . . . . . . . . . 64                       72            54            44             37            38        26
                                                         N = 185    N = 176       N = 157       N = 135        N = 100        N =69   N = 105
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . 28        30            36            33             23            22        35
                                                         N = 185    N = 176       N = 157       N = 135        N = 100        N =69   N = 105

N = number of observations.

                Table 4.—Average Dentist and Hygienist Time Used for Each Visit for the Keyes Technique

                                                         Visit 1     Visit 2      Visit 3            Visit 4    Visit 5       Visit 6       visit
Dentist       timea . . . . . . . . . . . . . . . . . . . . 28      22       20       21       19       22      20
                                                        SD=22.46 SD=19.83 SD=18.1O SD=19.00 SD=16.84 SD=18.17SD=17.56
                                                         N = 173  N = 138  N = 135  N = 111   N =93    N =50   N =92
Hygienist        timea . . . . . . . . . . . . . . . . . . 24       25         23        23        21         21       21
                                                       SD= 22.43 SD= 19.20 SD= 19.99 SD= 19.28 SD= 19.27 SD= 19.72 SD= 18.25
                                                         N = 140  N = 143    N = 117   N =99      N =69     N =53    N =83

SD= Standard deviation
N = mumber of observations.
Time in minutes.

and the maintenance visit), the amount of den-                                    the dentist and hygienist time.14 The scope cost
tist time in each visit declines, while amount of                                 is about $3,000, and we depreciate it over a 10-
hygienist time remains quite stable. (For pur-                                    year period. For the purpose of our estimates,
poses of our cost calculation, we assumed that                                    we allocate the cost of the scope to 100 patients
the dentist time is spent with only one patient.                                  being treated by the Keyes technique per year at
However, it is likely that some dentists are treat-                               $3 per visit. The cost of dentist time, based on

ing more than one patient at a time. If that is the                               the yearly income of and hours worked by a
case, our estimates of the average variable cost
of production may be too high. )
                                                                                        In a technical sense, once the scope is purchased, it is a fixed
  To estimate the average variable cost (in 1979                                  cost and not a variable cost. Since the cost of the scope is modest,
dollars) of producing the Keyes technique, we                                     deleting the cost from our estimate would have very little impact.
assume that the dental practice is already in
                                                                                        This estimate may be high, because dentists who use the Keyes
operation and that the only additional expenses                                   technique probably treat more than 100 patients a year. In any
                                                                                  event, the per unit cost of using the phase-contrast microscope is
for producing the Keyes technique are the cost                                    small; thus, alternative methods of computing its cost will have a
of the phase-contrast microscope and the cost of                                  small impact on our estimates.
general practitioner, is estimated at $25 per hour      maintenance visit, the average variable cost as a
(3). ” To estimate the cost of hygienist time, we       percentage of average charge is the lower than it
used the same costing procedure and added iS            is for any of the first six visits. For the dentists
percent for fringe benefits. This produced a cost       that charge for the Keyes technique on the basis
of $8 an hour for the hygienist time (3).17             of the total treatment cost, the average charge
                                                        per case was slightly over $120. This charge per
   To produce an estimate of the labor cost per
visit, we applied these hourly rates to the
                                                        case is comparable to the total charge, on a per
                                                        visit basis, of between five and six visits.
minutes of time used by the dentist and hygien-
ist. To this estimate, $3 was added for the use of         In addition to paying the dental charges for
the phase-control scope to produce estimates of         the Keyes technique, the patient needs to pur-
the average variable cost of producing each visit       chase an electric toothbrush and electrical irri-
(see table 5). According to our estimates, the          gating device at a total cost of $30 to $40. In
average variable cost of producing the initial          about half the cases treated by the Keyes tech-
visit is higher than that of producing subsequent       nique in our data base, drugs were utilized, usu-
visits. The difference in average variable cost         ally tetracycline. The cost for tetracycline per
mostly reflects the reduction of time spent by          prescription is between $8 and $10. In most in-
the dentist and the different range of services         stances, one or two prescriptions are required
provided following the initial visit (table 4).         for those patients using tetracycline. It is cur-
                                                        rentl y believed that after the patient has been
   Data from our survey on the average charge
                                                        treated successfully by the Keyes technique, two
for each visit are presented in table 5. Again it is
                                                        maintenance visits at an average charge of
interesting to note that the average charge is
                                                        about $26 per visit are required to ensure con-
highest for the initial visit. Moreover, for the
                                                        tinued oral health (29).
                                                           The Keyes technique may have benefits in ad-
                                                        dition to the treatment and prevention of peri-
                                                        odontal disease. In some patients, a benefit may
                                                        be a reduction in tooth loss. Furthermore, if sur-
                                                        gery is avoided, the pain and discomfort asso-
                                                        ciated with surgery are also avoided. By involv-
                                                        ing patients in improving their oral health, the
                                                        Keyes technique may improve their awareness
                                                        of dental disease and encourage their early use
                                                        of dental services, while the disease is still treat-
                                                        able, often at a reduced cost.

                Table 5.— Estimates of the Average Variable Cost of Producing Each Visit and
                           the Average Charge per Visit for the Keyes Technique
   Periodontal disease is a chronic disease that       with the Keyes technique averaged $31.63 and
affects over 90 percent of the adult population in     $27.83, respectively. Given the charge data on
the United States (6, 15,16,22,29). Today, treat-      visits, our average variable cost figures appear
ment of periodontal disease by dentists often in-      to be quite reasonable estimates.
volves surgery. The surgical procedures that are
used may be painful to the patient, and they              The cost effectiveness of the Keyes technique,
often carry with them postsurgical discomfort.         if i t does have a long-term effectiveness, de-
More importantly, our assessment of the scien-         pends in part on the amount of periodontal sur-
tific literature shows that the effectiveness of the   gery that is avoided. Although we are currently
surgery alone in the treatment of periodontal          unable to estimate this amount or to obtain an
disease has not been adequately demonstrated.          estimate from the published literature, the den-
                                                       tists in our study indicated that only between O
   The Keyes technique is so new that long-term
                                                       and 5 percent of patients being treated with the
efficacy and effectiveness studies have not been
                                                       Keyes technique also required a referral to a
possible, although the evidence to date appears
                                                       periodontist. If this estimate is correct and gen-
promising. Our analysis, based on data from 18
                                                       eralizable, then the potential savings of the
general practices in the Washington, D. C.,
                                                       Keyes technique are large.
SMSA on 190 patients being treated with the
Keyes technique and over 800 visits, found a
                                                          Our assessment of the literature on the effec-
measurable and statistically significant im-
                                                       tiveness of periodontal surgery suggests that
provement in each of the five indicators of den-
                                                       further long-term clinical studies are needed.
tal disease we employed. However, before more
                                                       Such studies would be quite useful if they were
definitive conclusions on the effectiveness of the
                                                       designed to compare the Keyes technique to
Keyes technique can be drawn, a more complete
                                                       periodontal surgery and included a control
and longitudinal study is required.
                                                       group which did not receive either treatment.
  Using our data base, we estimated the average        The patients under study should be randomly
variable cost of producing the Keyes technique         assigned to each of these three groups. The ran-
for 190 patients representing over 800 patient         dom assignment of patients into a nontreatment
visits. The estimated average variable cost of a       group raises an important ethical issue. How-
visit in 1979 was between $17.87 and $13.72, de-       ever, our assessment of the current method of
pending on whether it was an initial, followup,        treating periodontal disease raises serious ques-
or maintenance visit. These average variable           tions about its effectiveness, so the assignment
cost figures should be viewed as only rough esti-      of patients to a nontreatment group, with their
mates, and by definition they omit the fixed cost      informed consent, may be feasible. The costs of
of production (e. g., rent). By contrast, the re-      each of these alternatives—periodontal surgery,
ported charges in 1979 for the initial visit and       the Keyes technique, and no treatment—should
the maintenance visit for patients being treated       be computed and compared.
16 q Backround Paper #2: Case Studies of Medical Technologies


Calculus.—Calcium phosphate and carbonate with                  Periodontist. —A dental specialist who concentrates
  organic matter deposited upon the surfaces of the               on periodontal disease.
  teeth.                                                        Periodontitis. —Inflammation of the supporting
Cementum.—The bonelike connective tissue cover-                   structures of the teeth including bone, The use of
  ing the root of a tooth and assisting in tooth sup-             this term connotes destruction of the periodontal
  port.                                                           tissues.
Gingiva. —Gum of the mouth.                                     Periodontium. —The tissues investing and supporting
Gingivitis.–Inflammation of the gingiva (gum) only.               the teeth, including the cementum, periodontal lig-
Keyes technique.—A nonsurgical method of treating                 ament, alveolar bone, and gingiva.
  periodontal disease which involves microscopic                Plaque.—A gummy, almost exclusively bacterial
  determination of the microbial status, the applica-             substance which adheres to the teeth and is dis-
  tion of certain salt solutions in all instances, peri-          cernible only by applying stains, Plaque is the pri-
  odic courses of systemic antibiotics when indi-                 mary causative agent in periodontal disease.
  cated, and an extensive regimen of oral hygiene in-           Pocket.—The deepening of the normal space be-
  struction.                                                      tween the gum and the tooth due to inflammation.
Maintenance.— Patient seen periodically for assess-             Probing.—Placing a dental instrument under the gin-
 ment of periodontal health status, cleaning (pro-                giva or gum to determine whether or not bleeding
 phylaxis), microscopic assessment of bacterial ac-               will occur and to measure periodontal pockets, if
  tivity, and oral hygiene instruction if needed.                 present,
Mobile teeth. —Loose teeth.                                     Prophylaxis.—The use by professionals of appropri-
Mucogingival surgery. —Surgical removal of pockets                ate procedures and/or techniques to clean the
  involving soft tissue only as part of the surgical ap-          teeth.
  proach to treating periodontal disease.                       Radiograph.—A film of internal structures of the
Osseous surgery .—Surgical removal of bone as part                mouth produced by X-ray.
  of the surgical approach to treating periodontal              Root planing. –Smoothing of the root surfaces of the
  disease.                                                        teeth using certain instruments.
Quadrant. -A term used for descriptive purposes to              Scaling. —Removal of calculus material from the
  designate any one of four areas of the teeth and                tooth surfaces and that part of the teeth covered by
  gums (e.g., the upper right quadrant or the lower               the marginal gingiva.
  left quadrant).                                               Sulcus.—The normal space between the gum and the
Periodontal disease.—Diseases of the supporting                   tooth,
  structures of the teeth (e. g., gingivitis, periodon-
                      Case Study #S Periodontal Disease Assessing the Effectiveness and Costs of the Keyes Technique   q   17

    Dentist                                           Age         Years in Practice

    1.   Approximate length of time you have been using the Keyes technique:

    2.   For approximately how many patients have you used the Keyes technique?

         Do you use the Keyes technique as a preventive method as well as a t r e a t m e n t
                  Yes                               No

         Approximately what percentage of the patients with whom you have been using
         the Keyes technique also require some form of periodontal surgery?
                   o-5%               5-lo%                  10-20%                20-30%

    5.   How much do you refer patients to periodontists now as compared to before
         you began to use the Keyes technique?
                   More                  Less                 Same

    6.   Considering all of your patients that have been treated by the Keyes
         technique, approximately what percentage do you consider to have been
                   % Successfully                        % Unsuccessfully

    7.   What do you believe are the principal reasons for lack of success?
              (Use the back of this page if necessary.)

    8.   Would you be willing to allow me to ask the patients on whom you have
         completed a questionnaire to answer a few questions about their feelings?
                   Yes                              No

    9.   If yes, please sign your name:
I8 Background Paper #2: Case Studies of Medical Technologies

          Patient                                                                    Age      sex


          Date patient began treatment with Keyes technique                           Today's Date

          Total number of visits for the Keyes technique made by patient to date

          Total number of maintenance visits to date

                                                   PERIODONTAL STATUS
                                            (Please check where appropriate)

          At Initial Visit                                                                     At This Time

                                         Healthy, on maintenance care only
                                         Gingival inflammation only
                                         Bleeding on probing
                                         Radiographic evidence of bone loss
                                         Number of mobile teeth
                                         Number of quadrants of involvement
                                         Microscopic - many WBC's
                                         Microscopic - many motile forms

                                        ASSESSMENT OF PATIENT’S PLAQUE CONTROL

                                         Above average (doing well on own)
                                         Average (needs some professional instruction)
                                         Below Average (needs a great deal of
                                         professional instruction)

          Approximate total number of hours of plaque control instruction given
                               By whom:   Dentist
                                          Dental Assistant
                               Frequency of prophylaxis        times per year

                                       USE OF ANTIBIOTICS TO TREAT THE PATIENT

                                          Yes                    No

          I f y e s , h o w l o n g w a s e a c h c o u r s e ? -weeks.   How many courses?

                                                      PATIENT USES:
                                             (please check correct response)

         Baking soda and peroxide                  Yes         No
         Fluoride                                  Yes         No
         Irrigation                                Yes         No
         Other, please indicate                    Yes         No
                     Case Study #5: Periodontal Disease: Assessing the Effectiveness and Costs of the Keyes Technique   q   19

Has this patient been treated f o r p e r i o d o n t a l d i s e a s e prior to seeing you?
      Yes —        No—

If yes, was it by a general dentist                     or a periodontist ?

                            USING THE KEYES TECHNIQUE

                                          1st    2nd         3rd      4th     5th   6th          Maintenance

Dental history
Medical history
Visual assessment
Periodontal probing
Pocket measurement
Microscopic examination
Root planing
Plaque control instruction
Other                  (list)
Other                  (list)


1.   Average chair time per
     patient visit (minutes)

2.   How many minutes o f t h i s
     time was with:
          Dental Assistant
          Other (specify)

3.    Approximate cost to
      p a t i e n t per visit
                                        $ —       $—       $—       $—       $—       $—             $ —

4.    If cost w a s on the basis of a total case, what was the cost per case? $

5.    What was the average charge to patient for maintenance visit? $


If you feel that these questions will not show the correct information about
either effectiveness or cost using the Keyes technique for this patient, please
supply the information you believe will help on the back of this page.
20 . Background   Paper #2: Case Studies of Medical Technologies

 1. “Agents for the Control of Plaque: A Sym-                            Population, ” presented at the National Institutes
    posium Presented at the Meeting of the Interna-                      of Health Conference on Aging, Louisville, Ky.,
    tional Association for Dental Research, ” J. Dent.                   1975.
    Res. 58:2378, 1979.                                            16.   Kelly, J. E., and VanKirk, L. E., “Periodontal
 2. American Dental Association, Bureau of Eco-                          Disease in Adults: United States 1960-62, ” PHS
    nomic Research and Statistics, “Dental Fees                          publication No. 10 (Washington, D. C.: U.S.
    Charged by General Practitioners and Selected                        Government Printing Office, 1965).
    Specialists in the United States, 1977, ” J. Am.               17.   Keyes, P. H., et al., “The Use of Phase-Contrast
    Dent. Assoc., October 1978.                                          Microscopy and Chemotherapy in the Diagnosis
 3.          The 1977 Survey of Dental Practices                         and Treatment of Periodontal Lesions—An Ini-
      (O@&: ADA, 1977).                                                  tial Report (I), ” Quintessence lnternat. 1:5I,
 4. Axelson, P., and Lindhe, J., “Effect of Con-                         1978.
    trolled Oral Hygiene Procedures on Caries and                  18.             “The Use of Phase-Contrast Microscopy
    Periodontal Disease in Adults, ” J. Clin. Peri-                      and Chemotherapy in the Diagnosis and Treat-
    odont. 5:133, 1978.                                                  ment of Periodontal Lesions—An Initial Report
 5.            “The Effect of a Preventive Programme                     (II), Quintessence lnternat. 2:69, 1978.
    on Dental Plaque, Gingivitis, and Caries in                    19.   Lee, H., et al., “Experimental Gingivitis, ” Man.
    Schoolchildren: Results After One and Two                            J. Periodont. 36;177, 1965.
    Years,” ]. Clin. Periodont. 1:126, 1974.                       20.   Loesche, W. J., “Chemotherapy of Dental
 6. Chilton, N. W., and Miller, M. F., “Epidemiol-                       Plaque Infections, ” Oral Sci. Rev. 9:63, 1976.
    ogy of Periodontal Disease: Position Report and                21.   Pennel, B. M., and Keagle, J. G., “Predisposing
    Review of Literature, ” in International Con-                        Factors in the Etiology of Chronic Inflammatory
    ference on Research in the Biology of Periodon-                      Periodontal Disease, ” J. Periodont. 48:517,
    tal Disease (Ann Arbor, Mich.: University of                         1977.
    Michigan, 1977).                                               22.   Periodontal Disease and Oral Hygiene Among
 7. Cohen, D. W., “Role of Periodontal Surgery,”).                       Children, DHEW publication No. (HSM) 72-
    Dent. Res. 50:212, 1971.                                             1060 (Washington, D. C.: Department of Health,
 8. Committee Report, in lnternational Conference                        Education, and Welfare, 1972).
    on Research in the Biology of Periodontal Dis-                 23.   Ramfjord, S. P., “Surgical Pocket Therapy,”
    ease (Ann Arbor, Mich.: University of Michi-                         Int. Dent. J. 27;263, 1977.
    gan, 1977).                                                    24.   Ramfjord, S. P., et al., “Longitudinal Study of
 9. Committee Report: “The Etiology of Periodon-                         Periodontal Therapy, ” J. Periodont. 44:66,
    tal Disease, ” in World Workshop in Periodon-                        1973.
    tics, S. P. Ramfjord, et al. (eds. ) (Ann Arbor,               25.   Ranney, R. R., “Pathogenesis of Periodontal
    Mich.: University of Michigan, 1966).                                Disease: Position Report and Review of Litera-
10. Douglass, C. N., and Day, J. M., “Cost and                           ture, ” in International Conference on Research
    Payment of Dental Services in the United                             in the Biology of Periodontal Disease (Ann Ar-
    States,” J, Dent. Educ. 43(7) :33o, 1979.                            bor, Mich.: University of Michigan, 1977).
11. Garrett, J. S., “Root Planing: A Perspective, ” J.             26.   Rosling, B., et al., “The Effect of Systemic
    Periodont. 48:553, 1977.                                             Plaque Control on Bone Regeneration in Infra-
12. Gibson, R. M., “National Health Expenditures,                        bony Pockets, ” J. Clin. Periodont, 3:38, 1976.
    1978, ” Health Care Fin. Rev. 1(1), summer 1979.               27.             “The Healing Potential of the Periodon-
13. Henry, J. L., and Sinkford, H. C., “The Eco-                         tal Tissues Following Different Techniques of
    nomic and Social Impact of Periodontal Disease:                      Periodontal Surgery in Plaque-Free Dentitions, ”
    Position Report and Review of Literature, ” in In-                   J. Clin. Periodont. 36:233, 1976.
    ternational Conference on Research in the Biol-                28.   Rovin, S., “A Curriculum for Primary Care
    ogy of Periodontal Disease (Ann Arbor, Mich.:                        Dentistry, ” J.E. D. 41:176, 1977.
    University of Michigan, 1977).                                 29.   Sheiham, A., “Prevention and Control of Peri-
14. Hurt, W. C., “Periodontal Diagnosis–1977: A                          odontal Disease, ” in International Conference
    status Report, ” J. Periodont, 48:533, 1977.                         on Research in the Biology of Periodontal Dis-
15. Ingle, J. I., “The Health, Economic, and Cultural                    ease (Ann Arbor, Mich,: University of Michi-
    Impact of Periodontal Disease on Our Aging                           gan, 1977).
                            Case Study #.5 Periodontal Disease: Assessing the Effectiveness and Costs of the Keyes Technique q 21

30. Soransky, S. S., “Microbiology of Periodontal       ature, ” in International Conference on Research
    Disease—present Status and Future Considera-        in the Biology of Periodontal Disease (Ann Ar-
    tions, ” J. Periodotlt. 48:497, 1977.               bor, Mich.: University of Michigan, 1977).
31. Suomi, J. D., et al., “The Effect of Controlled 33. U.S. Department of Health, Education, and
    Oral Hygiene Procedures on the Progression of       Welfare, “Edentulous Persons, United States, ”
    Periodontal Disease in Adults: Results After        National Center for Health Statistics, series 10,
    Third and Final Year, ” J. Periodont. 42:152,       No. 89, 1971.
    1971.                                           34. Zander, H. A., and Poison, A. M., “Present
32. Tanzer, J. M., “Microbiology of Periodontal         Status of Occlusion and Occlusal Therapy in
    Disease: Position Report and Review of Liter-       Periodontics, ” J. Periodont. 48:540, 1977.

                 Editor of Commentary:
              AlIan J. Formicola, D.D.S.
Dean, School of Dental and Oral Surgery
                   Columbia University

                    R. Gottsegen, D.D.S.
                  Professor of Dentistry
                Director of Periodontics
                     School of Dentistry
                    Columbia University

                   S. Socransky, D.D.S.
                  Senior Staff Member
                  Head of Periodontics
                 Forsyth Dental Center

                           J. Hay, Ph. D.
                   Assistant Professor
             School of Dental Medicine
              University of Connecticut
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Diagnosis of Periodontal Disease and Monitoring of Disease Activity . . . . . . . . . . 26
    Are the Samples Representative? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
    Is the Test Diagnostic of Disease Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
The Use of Salt, Hydrogen Peroxide, Sodium Bicarbonate, andTetracycline
  as Therapeutic Agents in the Control of Periodontal Disease and the Use
  of PhaseMicroscopy as a Patient Motivator . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Economic Perspectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
                                                                                            Editor of Commentary:
                                                                                  AlIan J. Formicola, D. D.S.*
                                                                     Dean, School of Dental and Oral Surgery
                                                                                         Columbia University
                                                                                              New York, N.Y.

   Periodontal disease is ubiquitous, affecting 80                   by publication in scientific journals. Studies not
to 90 percent of the adult population. It may                        adhering to these standards are not scientifically
range from simple gingivitis to advanced de-                         valid, and their results must be considered anec-
structive periodontitis in which there is destruc-                   dotal. Scheffler and Rovin’s study of the Keyes
tion of the supporting tissues around the teeth,                     technique in 18 dental practices in the Washing-
resulting in tooth loss.                                             ton, D. C., area does not adhere to these stand-
  Treatment of early, or mild, periodontal dis-                      ards.
ease is usually simple, short, and successful.                          However, there is in the scientific literature
Treatment of advanced periodontitis, though                          abundant well-documented evidence that
more involved and protracted, has a high suc-                        plaque removal and subsequent control arrests
cess rate. Further, treatment is based on the                        or reverses gingivitis and early periodontitis.
long-term experience of many expert clinicians                       Since the Keyes technique relies principally on
and observers, supported by sound clinical                           plaque removal and control, it is not a new
research.                                                            technique at all, for plaque removal and control
   The criteria for a clinical investigation to be                   are exactly what all dentists who treat periodon-
considered as having scientific merit are the                        tal disease do as the initial and basic part of their
following: I) the use of reliable and standard-                      therapy.
ized measurements; 2) adequate controls, par-                           For hundreds of years, periodontal treatment
ticularly in clinical trials; 3) presentation of data                has been based on the removal of hard and soft
in a form allowing appropriate statistical anal-                     deposits from tooth surfaces. This therapy has
ysis; and a) submission of reports to peer review                    been quite effective. However, cases of ad-
   *In addition to Dr. Formicola, the primary authors of this com-   vanced periodontal disease may require the use
mentary are: R. Gottsegen, Professor of Dentistry, Director of       of surgical procedures for the proper debride-
Periodontics, School of Dentistry, Columbia University; S. So-       ment of inaccessible microbial masses and cal-
cransky, Senior Staff Member, Head of Periodontics, Forsyth
Dental Center; and J. Hay, Assistant Professor, School of Dental
                                                                     culus. The depths of periodontal pockets or
Medicine, University of Connecticut.                                 other difficult to reach places cannot be thor-
  The authors gratefully acknowledge the contributions of the        oughly cleansed unless exposed surgically. In-
following individuals: John J. Bergquist, Professor and Chairman
of Periodontics, University of Maryland; R. Caffesse, Professor
                                                                     deed, root surfaces with periodontal pockets
and Chairman of Periodontics, School of Dentistry, University of     deeper than 5 mm may still harbor significant
Michigan; D. Fine, Associate Professor of Dentistry, School of       numbers of micro-organisms despite careful
Dentistry, Columbia University; P. Kamen, Assistant Professor of
Dentistry, School of Dentistry, Columbia University; J. Kennedy,
                                                                     scaling by skilled operators (12). A further bene-
Professor of Dentistry and Dean, School of Dentistry, Virginia       ficial effect of the surgical approach may be to
Commonwealth University; A. Poison, Chairman of Periodontics,        reduce pocket depth, thus making formerly in-
Eastman Dental Center, and Associate Professor, University of
Rochester; and R. Rosenberg, Assistant Clinical Professor, School    accessible areas accessible for the patient to ex-
of Dentistry, Georgetown University.                                 ercise plaque control.

26 q Background Paper #2: Case Studies of Medical Technologies

   A study of the result of conventional therapy                    There are other careful long-term studies
was reported by Hirschfeld and Wasserman in                      which have demonstrated the long-term success
1978 (l). This study involved 600 patients, most                 of conventional treatment: Ramjford, et al. (7),
of whom had advanced periodontal disease. All                    Knowles, et al. (3), Lindhe and Nyman (4), and
these patients had been referred to a periodontal                Nyman and Lindhe (6). These studies followed
specialist for care because they were in immi-                   the patients for periods of time up to 10 years
nent danger of losing teeth. All 600 received                    after treatment. Treatment was careful prepara-
conventional periodontal treatment, which for                    tion of the patient by scaling, plus motivation
many included surgery when indicated; and all                    and training in oral hygiene. Surgery was indi-
then had followup care for 15 to 50 years (with a                cated because of the severity of the patients’
mean duration of observation of 22 years).                       periodontal disease.
Eighty-three percent of these patients lost only O
                                                                    All of these studies constitute strong evidence
to 3 teeth. The fact that these patients with ad-
                                                                 that conventional periodontal therapy, includ-
vanced disease lost so few teeth during that long
                                                                 ing surgery and proper maintenance by the den-
time span demonstrates the success of conven-
                                                                 tist and the patient, can stop the progress of ad-
tional periodontal therapy. However, a small
                                                                 vanced periodontal destruction and maintain
subgroup of 25 patients (4.2 percent) in this
                                                                 the dentition in the majority of cases.
study lost more than 10 teeth in the 22-year fol-
lowup period. Recent evidence from other stud-                      When comparing these well-designed studies
ies suggest that this subgroup of patients prob-                 of conventional treatment that have been re-
ably had a more aggressive or rapidly progress-                  ported in the scientific literature to the study of
ing form of adult periodontitis.                                 the Keyes technique by Scheffler and Rovin, one
                                                                 must point out that the Keyes technique in-
   It should be noted that the Hirschfeld and
                                                                 volves the same antimicrobial approach as con-
Wasserman study did not include patients with
                                                                 ventional therapy. However, Keyes only rarely
simple gingivitis or early periodontitis; the
                                                                 accepts the use of surgery to gain access to more
study examined only the results of conventional
                                                                 deeply involved areas. His method is to flush
treatment of patients with advanced periodontal
                                                                 such areas with salt solutions, which, he states,
disease. No similar conclusions regarding the ef-
                                                                 is sufficient to kill pathogenic bacteria. Whether
fectiveness of the Keyes technique in the treat-
                                                                 salt solutions actually achieve this goal is not
ment of advanced periodontal disease can be
                                                                 clear at this time. Thus, it is premature to sug-
drawn from the study by Scheffler and Rovin
                                                                 gest that this treatment regimen alone should be
for two reasons. One, the authors provide no
                                                                 used in human patients as a replacement for
useful information indicating the severity of the
                                                                 techniques that have been documented to con-
patients’ disease, and two, their study is of such
                                                                 trol periodontal diseases.
short duration that it is valueless for judging the
long-term effect of the Keyes technique on ad-
vanced periodontal disease.

  The Keyes technique employs a diagnostic                       tions: 1) that the microbiologic samples taken
test that has not yet been validated as a measure                are representative of the microbiota (bacterial
of disease activity, namely, phase-microscopic                   population) in the worst-diseased sites, and
examination of wet samples of material scooped                   2) that the test is diagnostic of disease activity
out of periodontal pockets. Implicit in reliance                 and can also be used to monitor the effects of
on this test are at least two unproved assump-                   treatment.
                           Case Study #5: Periodontal Disease: Assessing the Effectiveness and Costs of the Keyes Technique q 27

Are the Samples Representative?                               proportion of motile forms on a microscopic
                                                              slide is not substantiated by scientific evidence.
   The basis of choosing the sites for sampling of            Research on the possible existence of such a rela-
subgingival plaque has not been clearly defined               tionship is just now being invited in a “Request
by Keyes, apart from a statement that “particu-               for Proposals” issued by the National Institutes
lar effort is made to obtain samples from deeper              of Health (RFP No. NIH-NIDR-81- 3R).
subgingival spaces that are difficult for the pa-
tient to clear (sic)” (2). That the samples are                  However, there is at this time a limited
representative is an unwarranted assumption,                  amount of established knowledge about the re-
because there is a dramatic variation in the bac-             lationship of motile organisms and periodontal
terial population from site to site within the                disease. That phase microscopy could be sen-
same individual, from supragingival (above the                sitive to all forms of active periodontal destruc-
gum margin) sites to subgingival (below the                   tion is doubtful. For example, in the case of peri-
gum margin) sites, from diseased sites to healthy             odontosis, an actively progressive periodontal
sites, and between sites with different forms of              disease that causes major destruction of bone
periodontal disease (5,8,9,10). Therefore, there              surrounding the teeth in young individuals,
is no basis for using a sample of bacteria from               there are few motile organisms even though the
one area as an indication of the bacterial pop-               disease is progressing at a rate generally consid-
ulation of the plaque from a patient’s mouth.                 ered to be much faster than that of adult perio-
                                                              dontitis. The organism that has been shown to
Is the Test Diagnostic of                                     be uniquely and closely associated with this
Disease Activity?                                             condition is not motile.
  Any proposed diagnostic test must be vali-                    Thus, it seems clear that to date there is no
dated. The one used in the Keyes technique has                convincing rationale for the use of phase micro-
not been. Keyes’ claim that the state of disease              scopy for either of the two uses suggested by
activity can be determined by examining the                   Keyes.

   A widespread group of therapeutic modalities               unjustified. Furthermore, no evidence is avail-
is employed in the Keyes technique. One modal-                able which suggests that the local applications
ity is scaling, which as stated above has been                of salt solutions or pastes or hydrogen peroxide
shown to be effective in controlling periodontal              reduce the rate of periodontal destruction, pre-
disease. In addition, Keyes advocates local ap-               vent the recurrence of active periodontal lesions
plications of concentrated salt solutions and/or              in a treated patient, or add anything to the ex-
pastes of sodium chloride, magnesium chloride,                isting regime of periodontal therapy.
hydrogen peroxide, and often the systemic ad-
ministration of tetracycline (an antibiotic) under              Keyes and followers assert that phase micros-
certain conditions. At present, tetracycline has              copy has value in motivating a patient to per-
been shown to be needed in only a small number                form proper oral hygiene. This assertion is
of cases which responded poorly to routine ther-              based on the assumption that patients are more
apy. The use of this drug in about half of the pa-            willing to follow the dentist’s directions to clean
tients treated by the Keyes followers in Scheffler            their mouths properly when shown the living
and Rovin’s Washington area study is totally                  bacteria which can be scraped off their teeth.
28 q Background Paper #2: Case Studies of Medical Technologies

However, the American Society of Preventive                      tients, found that the technique does not pro-
Dentistry, which in the 1960’s spearheaded an                    vide a better approach to patient motivation
effort to use phase microscopy to motivate pa-                   than traditional modes of hygiene instruction.

   CBAS and CEAS of medical-dental procedures                    capital costs of dental office visits. Even these
are essentially accounting procedures carried                    figures are inconclusive. The authors’ data are
out to determine if a given program, or in this                  not clear and do not specify whether all of the
case a treatment regimen, is worth the effort.                   dentists were providing the same mix of dental
These analytic techniques have become increas-                   services. Their cost estimates might differ con-
ingly sophisticated in the last 5 years (11,13).                 siderably if periodontists or general practi-
CBA relates the total costs of receiving such                    tioners proficient in periodontal surgery were
treatment to the total benefits, while CEA com-                  included in the data sample.
pares the costs of one treatment modality to                       A more glaring deficiency, which the authors
those of another, or to a group of alternative                   have acknowledged by disclaimer, is the lack of
treatments, having established that all of the
                                                                 any estimates of patient opportunity costs, both
treatments meet a minimum acceptable level of
                                                                 in the dental office visits and in home oral
effectiveness.                                                   hygiene. Generally speaking, patient opportuni-
   Scheffler and Rovin do not present a complete                 ty costs would capture the value of resources
picture of costs and benefits nor of the costs of                consumed by the patient in addition to dental
alternative treatments. Although they discuss                    office charges. These costs would include trans-
alternative surgical and nonsurgical techniques,                 portation costs to visit the dentist, time spent in
they do not present the types of data necessary                  home oral hygiene, etc. They would also include
to compare these alternatives with the Keyes                     dentist opportunity costs, e.g., the cost of train-
technique.                                                       ing personnel to carry out the Keyes regimen.
  The only costs that Scheffler and Rovin pre-
sent are certain average variable labor and

   Researchers can point to mounting evidence                    centers, supported cooperatively by universities
that dentistry is gaining the scientific knowledge               and the National Institutes of Health.
that will provide the public some measures for
                                                                    While our scientific knowledge base for peri-
the prevention and management of periodontal
                                                                 odontal disease may lag behind that for caries,
disease. Dentistry has repeatedly demonstrated
                                                                 significant advances have been made in the last
its willingness to support major public health ef-
                                                                 decade and a half by a diverse and dedicated
forts. Dental researchers and practitioners have
                                                                 group of scientists and concerned clinicians.
actively participated in the development of the
scientific base, clinical applications, and pro-                    We understand and sympathize with the goal
motion of measures to control dental caries                      of Dr. Keyes and coworkers as well as Drs.
through the use of fluoride and, more recently,                  Scheffler and Rovin to provide better, simpler
sealants. Now the dental research community is                   and less expensive therapy to all periodontal pa-
seeking to conquer caries totally by developing                  tients, because this is a goal shared by all in-
a caries vaccine. Research towards this goal is                  dividuals in periodontal research. However, the
being carried out at a number of research                        standard for acceptance of therapy cannot
                            Case Study #5: Periodontal Disease: Assessing the Effectiveness and Costs of the Keyes Technique q 29

become enthusiastic advocacy, popular appeal,                  ance of the former as standards would be as a
and press releases, but must be carefully con-                 sharp step backward for the dental profession
trolled clinical and laboratory testing. Accept-               and for the public.

1, Hirschfeld, L., and Wasserman, D., “A Long-                   7. Ramfjord, S. P., et al., “Longitudinal Study of
   Term Survey of Tooth Loss in 600 Treated Peri-                   Periodontal Therapy, ” J. Periodont. 44:66,
   odontal Patients, ” J. Periodont. 49:225, 1978.                  1973.
2. Keyes, P. H., et al., “The Use of Phase-Contrast              8. Slots, J., “Subgingival Microflora and Periodon-
   Microscopy and Chemotherapy in the Diagnosis                     tal Disease, ” J, Clin. Periodont. 6:351, 1979.
   and Treatment of Periodontal Lesions—An Ini-                  9. Socransky, S. S., “Microbiology of Periodontal
   tial Report (I), ” Quintessence Internat. 1:51,                   Disease—Present Status and Future Considera-
   1978.                                                             tions, ” J. Periodont, 48:497, 1977.
3. Knowles, J. W., et al., “Results of Periodontal             10, Syed, S. A., and Loesche, W. J., “Bacteriology
   Treatment Related to Pocket Depth and Attach-                   of Human Experimental Gingivitis: Effect of
   ment Level: Eight Years, ” J. Periodont. 50:225,                Plaque Age, ” Infect. and Immun. 21:821, 1978.
   1979.                                                       11. Thompson, M., Benefit-Cost Analysis for Pro-
4. Lindhe, J., and Nyman, S., “The Effect of                       gram Evaluation (Beverly Hills, Calif.: Sage
   Plaque Control and Surgical Pocket Elimination                  Press, 1980).
   on the Establishment and Maintenance of Peri-               12. Waerhaug, J., “Healing of the Dento-Epithelial
   odontal Health: A Longitudinal Study of Perio-                  Junction Following Subgingival Plaque Control,
   dontal Therapy in Cases of Advanced Periodon-                   II: As Observed on Extracted Teeth, ” J. Perio-
   titis, ” J. Clin, Periodont. 2:67, 1975.                        dent. 49:119, 1978.
5. Listgarten, M. A., and Hellden, L., “Relative               13. Warner, K., and Luce, B., Cost-Benefit and
   Distribution of Bacteria at Clinically Healthy                  Cost-Effectiveness Analysis in Health Care:
   and Periodontally Diseased Sites in Humans, ” J.                Principles, Practice and Potential (Ann Arbor,
   Clin. Periodont. 5:115, 1978,                                   Mich.: Health Administration Press, in press,
6. Nyman, S., and Lindhe, J., “A Longitudinal                      1981).
   Study of Combined Periodontal and Prosthetic
   Treatment of Patients With Advanced Periodon-
   tal Disease,” J. Periodont, 50:163, 1979.

   In his commentary, Dr. Formicola includes         on any statistical basis; there were no control
among the criteria for evaluating a scientific       groups; and the same dentists who performed
clinical investigation the use of adequate control   the treatment also evaluated it. The Hirschfeld
groups, and he further states that studies with-     and Wasserman study was a retrospective anal-
out such controls must be considered “anec-          ysis of treatment and was not predicated on a
dotal. ” A control group in a clinical study is      predetermined treatment modality. Moreover,
generally defined as a group of patients which is    there was no rating reliability between the eval-
comparable to the treatment group but which          uators. In fact, some of the patients were treated
does not receive the therapy that is to be           by different dentists at different points in time.
studied. However, the clinical studies of perio-     Finally, no statistical tests were used to analyze
dontal therapy that Dr. Formicola cites do not       the data.
use control groups; instead, they report the im-        However, even if we ignore these limitations,
pact of the application of one therapeutic mo-
                                                     the evidence in the Hirschfeld and Wasserman
dality or another. Thus, according to Dr.
                                                     study (1) points more to the retention of teeth
Formicola’s commentary, these studies should
                                                     without periodontal surgery than it does to
be labeled “anecdotal. ”
                                                     retention with surgery. Of the 600 patients in
   Actually, the lack of control groups is a fun-    the study, only 230 (39.3 percent) had periodon-
damental problem found in most of the litera-        tal surgery in the first place. According to
ture on periodontal disease. Specifically, there     Hirschfeld and Wasserman, most of the patients
have been few controlled clinical studies in         responded just as well without surgery as with
which a treatment group received periodontal         it: “. . . in the great majority of cases surveyed,
procedures and a control group received no           simple but thorough treatment in the form of
therapy at all. The one major study that did use     subgingival scaling, occlusal adjustment, and
a control group (4) dealt with the use of oral       fair to good home care seemed to reduce tooth
hygiene procedures only; it did not include sur-     loss.” The investigators concluded: “The mor-
gical procedures. That investigation was cited in    tality of teeth which were treated with periodon-
our case study, but not in Dr. Formicola’s com-      tal surgery was compared with that of teeth
mentary.                                             which did not have surgery. Tooth retention
                                                     seemed more closely related to the case type
   There are no scientific studies which show
                                                     than the surgery performed. ”
that the surgical approach to treating periodon-
tal disease is any better than the conservative         Although Dr. Formicola implies otherwise,
approach used by clinicians for many years. Ac-      the Hirschfeld and Wasserman study cannot be
tually, a major recommendation in our case           considered anything other than what he terms
study is that such controlled clinical studies be    “anecdotal, ” for the reasons we have cited.
carried out: “Our assessment of the literature on    Hirschfeld and Wasserman appropriately entitle
the effectiveness of periodontal surgery suggests    their study a survey, “A Long-Term Survey of
that further long-term clinical studies are          Tooth Loss in 600 Treated Periodontal Pa-
needed. Such studies would be quite useful if        tients. ” This label is not to denigrate their effort
they were designed to compare the Keyes tech-        because the effort did provide useful and impor-
nique to periodontal surgery and included a          tant information.
control group which did not receive either treat-
                                                        Many of the other clinical studies cited by Dr.
ment .“
                                                     Formicola are deficient because dentists who
   In his commentary, Dr. Formicola spoke at         performed the surgical therapy also evaluated
great length about the Hirschfeld and Wasser-        the results; independent evaluations were usual-
man study (1) and suggested that it was an ex-       ly absent. The Ramfjord group of studies (3)
ample of research with scientific merit. How-        had some standardization in that the same eval-
ever, it should be noted that in this study, pa-     uators were used throughout, but even in these
tient samples were not randomized nor selected       studies, it is not clear in some cases whether the

dentists who performed the evaluation did not
also perform the surgery. An even more serious
deficiency is the absence of a control group.
   Thus, none of the clinical studies which were
cited by Dr. Formicola conforms to his own cri-
teria for scientific merit. Unfortunately, the clin-
ical studies which occupy the bulk of the perio-
dontal literature lack scientific rigor. But these
are the studies on which periodontal therapy is
predicated. To repeat, the need for randomized
controlled clinical studies of alternative treat-
ments for periodontal disease is essential, so
that effective periodontal treatments can be
   We find it disappointing that Dr. Formicola
believes that cost-benefit analysis (CBA) and
cost-effectiveness analysis (CEA) are “essential-
ly accounting procedures, ” despite the effort
that OTA has made in explaining these con-
cepts. According to OTA: “The terms CEA and
CBA refer to formal analytical techniques for
comparing the positive and negative conse-
quences of alternative ways to allocate re-
sources” (2), OTA found no consensus among
analysts and practitioners as to a standard set of
methods for CEA/CBA (2). Accounting proce-
dures have little, if anything, to do with the ana-
lytical technique of CEA or CBA.
   We conducted a CEA of the Keyes technique,
but because there was no existing CEA of perio-
dontal surgery, we could not compare the Keyes
technique to the surgical alternative. We did
find national data which show that surgery is
much more expensive than the Keyes technique.
Surgery on a single quadrant of the mouth costs
the patient an average of at least $250, whereas
six visits for the Keyes program cost about $150.
Thus, even without including the cost of follow-
up treatments after surgery, the cost to the pa-
tient is considerably higher when surgery is per-
formed than when the Keyes technique is used.
As Dr. Formicola points out, the costs of the
Keyes technique would be different if periodon-
tists performed it instead of general practice
dentists. However, we see no reason to use the
higher wages of periodontists in our calculations
if general practice dentists can deliver the Keyes
32 q Background Paper #2: Case Studies of Medical Technologies

warrant a long-term comprehensive investiga-                         allow the treatment of many more patients with
tion. If the Keyes program should prove effec-                       periodontal disease, as well as reduce the
tive in the long run, it could reduce the cost of                    amount of periodontal surgery and its costs.
controlling periodontal disease and perhaps

REFERENCES                                                       q

1. Hirschfeld, L., and Wasserman, D., “A Long-                       3. Ramfjord, S. P., et al., “Longitudinal Study of
   Term Survey of Tooth Loss in 600 Treated Perio-                      Periodontal Therapy,” ]. Periodont. 44:66, 1973.
   dontal Patients,” ]. Periodorzt. 49:225, 1978.                    4. Suomi, J. D., et ;j., “The Effect of Controlled
2. Office of Technology Assessment, U.S. Congress,                      Oral Hygiene Procedures on the Progression of
   The Implications of Cost-Effectiveness Analysis                      Periodontal Disease in Adults: Results After
   of Medical Technology, GPO stock No. 052-                            Third and Final Year,” ]. Periodont. 42:152, 1971.
   003-00765-7 (Washington, D. C.: U.S. Govern-
   ment Printing Office, August 1980).

                                                                                 * U S GOVERNMENT PRINTING OFFICE   1981 341 -844/1007