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									TWENTY-SECOND ANNUAL
  RESEARCH PROGRAM


     WEDNESDAY
   FEBRUARY 15, 2006
Contents


Organizing Committee ............................................................................................................ page 2

Fellowships, Awards, and Recognitions ................................................................................. page 3

Program Schedule ................................................................................................................ page 4-5

Student Researchers .............................................................................................................page 6-7

Program ............................................................................................................................ pages 8-10

Abstracts ........................................................................................................................ pages 11-68




Twenty-second Annual Student Research Program Scientific Session:                                                                            1
February 15, 2006
Organizing Committee


Dean .......................................................................................................................... Jan Kronmiller

Associate Dean of Research........................................................................................ John Sheridan

Director, Student Research Programs,
Advisor SRG ....................................................................................................William M. Johnston

College of Dentistry Research Committee
Chairperson ............................................................................................................... Scott Schricker

Student Table Clinics Committee Chairperson.......................................................... Lisa Knobloch

Administrative Assistant .......................................................................................... Christine Bitzel


OSU Student Research Group


President ........................................................................................................................ Heidi Snider

Vice-President ................................................................................................................ Kyle Bogan

Secretary/Treasurer ............................................................................................. Kelly Moneysmith




Twenty-second Annual Student Research Program Scientific Session:                                                                            2
February 15, 2006
Student Awards

Awards for 2005 Ohio State University College of Dentistry Student Research Competition
include the first place award, the ADA Dentsply Student Clinician Award at The Ohio State
University. The winner of this award qualified to be entered into the national ADA Dentsply
Student Clinician Award competition at the annual ADA Scientific Session, sponsored by
Dentsply International. The 2005 ADA Dentsply Student Clinician Award winner at The Ohio
State University is Jacki W. Mays.

The second place award for the Student Research Competition is the Alumni Research Merit
Award. The winner of this 2005 award qualified to be entered into the Hinman Student Research
Symposium competition, with expenses paid for by the Thomas P. Hinman Dental Society, the
National Institute of Dental and Craniofacial Research and the Proctor and Gamble Company.
The 2005 Alumni Research Merit Award winner is Heidi Snider.

The third place award for student researchers is the Alumni Research Achievement Award. The
winner is qualified to also be entered into the Hinman Student Research Symposium
competition. The 2005 Alumni Research Achievement Award winner is Kathryn Lubitz




Twenty-second Annual Student Research Program Scientific Session:                             3
February 15, 2006
Research Day Schedule


February 15, 2006

Medical Heritage Center
376 W. 10th Avenue
5th Floor

           Time                                                Event

  7:30-9:30 AM          Poster Judging and Light Continental Breakfast
  9:30-10:00 AM         Opening Remarks by Dean Kronmiller and Dr. Scott Schricker
  10:00-10:30 AM        Dr. Steve Lee, Department of Biomedical Engineering: “Protein
                        Engineering to Support Nanoscale Sensing and Detection
                        Modalities”
  10:30-11:30 AM        Student Oral Presentations – 5th Floor Meeting Room
  11:30-12:00 PM        Dr. Scott Schricker, Section of Restorative and Prosthetic Dentistry:
                        “Nanostructures for Dental Materials and Biomaterials”
  12:00-1:30 PM         Lunch – 5th floor Meeting Room
      All afternoon poster presentations will be held in the Medical Heritage Center
                                 Meeting Room (5th Floor)
  1:30-2:00 PM          Dr. John Lannutti, Department of Materials Science Engineering:
                        “Electrospun Scaffolds for Tissue Engineering”
  2:00-2:30 PM          Dr. Sarandeep Huja, Section of Orthodontic Dentistry: “Bone
                            Remodeling in the Alveolar Process”
  2:30-4:30 PM              Student Poster Presentations – 5th Floor Meeting Room
                            Student Oral Presentations – 4th Floor (400B)




Twenty-second Annual Student Research Program Scientific Session:                               4
February 15, 2006
Research Day Recognition Banquet (for Student Research Programs Participants)


February 17, 2006

Faculty Club,
South Oval Drive

        6:00 PM                  Social Hour

        7:00 PM                  Dinner (by reservation only)

        8:20 PM                  Welcome and Student Recognition




Twenty-second Annual Student Research Program Scientific Session:               5
February 15, 2006
Student Researchers

Presenter                         Mode                        Program
Satish Alapati                    Oral                        Oral Biology
Paul Allen                        Poster                      Dentistry
Hamad Alzoman                     Oral                        Periodontology
Ashley Beroske                    Poster                      Dentistry
Gayle Bline                       Poster                      Dental Hygiene
Kyle Bogan                        Poster                      Dentistry
Joshua Burns                      Poster                      Dentistry
Kendell Buxton                    Poster                      Dentistry
Julie Carnes                      Poster                      Dental Hygiene
Billy Cho                         Poster                      Periodontology
Daniel Choi                       Poster                      Dentistry
Daniel Claman                     Poster                      Dentistry
Jessica Davis                     Poster                      Dental Hygiene
Samuel DeAngelo                   Poster                      Periodontology
David Defay                       Poster                      Dentistry
Phing Dong                        Poster                      DDS/PhD
Randy Fitzgerald                  Poster                      Periodontology
Ben Frandsen                      Oral                        Dentistry
Christopher Gamble                Poster                      Dentistry
Tobi Gbemi                        Poster                      DDS/PhD
Laura Geran                       Poster                      Postdoc
Kelly Gerhardstein                Poster                      Dentistry
Erin Gross                        Poster                      DDS/PhD
David Gustafson                   Poster                      Dentistry
Cyndi Head                        Poster                      DDS/PhD
Mike Horan                        Oral                        DDS/PhD
Xingxue Hu                        Oral                        Dental Materials
Dustin Jacobs                     Poster                      Dentistry
Steve Kinsey                      Oral                        Psychology/PhD
Dongfa Li                         Poster                      Dental Materials
Hsuan Li Lin                      Poster                      Dentistry
Ruohong Liu                       Oral                        Advanced Prosthodontic
Peter Lovejoy                     Oral                        Dentistry
Jacki Mays                        Poster                      DDS/PhD
Pooja Maney                       Poster                      Oral Biology/PhD
Issac Meta                        Poster                      Oral Biology/PhD
Adam McCormick                    Poster                      Dentistry
Kelly Moneysmith                  Poster                      Dentistry
Patrick Nolan                     Poster                      Dentistry
Brent Paulus                      Poster                      Dentistry
Ellen Prochaska                   Poster                      Dentistry
Jahnavi Rao                       Poster                      Orthodontics
Tyler Robb                        Oral                        Dentistry
Thasanai Roongruangphol           Poster                      Advanced Prosthodontic
Andrew Rummel                     Poster                      Dentistry
Yurdanur Sanli                    Oral                        Oral Biology/PhD
Kara Schafer                      Poster                      Dentistry




Twenty-second Annual Student Research Program Scientific Session:                      6
February 15, 2006
Student Researchers Continued
Robert Scoresby                   Poster                      Dentistry
Kumar Shah                        Oral                        Advanced Prosthodontic
Danen Sjostrom                    Poster                      DDS/PhD
Heidi Snider                      Poster                      DDS/PhD
Prem Sundaralingam                Poster                      Orthodontics
Leslie Thomas                     Poster                      Periodontology
David Thurman                     Poster                      Dentistry
Kate Varley                       Oral                        Dentistry
Joseph Whitesides                 Poster                      Dentistry
James Ziuchkovski                 Poster                      Orthodontics




Twenty-second Annual Student Research Program Scientific Session:                      7
February 15, 2006
Oral Sessions

                                    Morning Session
                                   10:30-11:30 A.M.
                      5th Floor of Prior Health Sciences Library
                                    Meeting Room
#      Time/Location Presenter      Title
O1     10:30-10:45   Ruohong        Effect of Metal Recasting on Porcelain-Metal Bonding
                     Liu            Using Force-to-Failure Measurements
O2     10:45-11:00   Mike Horan N-Acetyl-L-Cysteine Upregulates TIMP-1 And TIMP-2
                                    Expression In Squamous Cell Carcinoma
O3     11:00-11:15   Kate Varley Digital Removable Partial Denture Design

O4     11:15-11:30                Metallurgical Characterization of Cast-To Implant
                           Yurdanur
                           Sanli  Components from Five Companies
                                Afternoon Session
                                 2:30 – 4:30 P.M.
                  th
                 4 Floor of Prior Health Sciences Library (400B)
#   Time/Location Presenter       Title
O5 2:30-2:45       Tyler Robb     Androstenetriol Modulates Apopotosis by Regulating
                                  the Expression of Bcl-2
O6 2:45-3:00       Peter          Androstendiol Inhibits Influenza Virus Replication in
                   Lovejoy        Human Respiratory Epithelial Cells
O7 3:00-3:15       Ben            In Vitro Evaluation of Three Designs of Implant
                   Frandsen       Placement for Supporting Maxillary Overdentures
O8 3:15-3:30       Kumar Shah Physical Properties of Cerium-doped Tetragonal
                                  Zirconia (10mins)
O9 3:30-3:45       Steve Kinsey Aged Mice are More Susceptible to Defeat-Induced
                                  Hyperinflammation than Young Adult Mice
O10 3:45-4:00      Hamad          Osteoprotegerin Inhibits Periodontal Alveolar Bone
                   Alzoman        Loss in Susceptible Animals
O11 4:00-4:15      Xingxue Hu Effects of Porcelain-Firing and Annealing Heat
                                  Treatments on Palladium-Silver Alloys
012 4:15-4:30      Satish         Investigation of Transformations in Used and Heat-
                   Alapati        Treated Nickel-Titanium Endodontic Instruments




Twenty-second Annual Student Research Program Scientific Session:                         8
February 15, 2006
      Poster Sessions

#     Presenter             Title
P1    Paul Allen            Success of Mandibular Immediate Load Hybrid Dentures
                            Acquisition by Children of Gram-Positive Bacteria Associated with
P2    Ashley Beroske
                            Periodontitis
P3    Gayle Bline
P4    Kyle Bogan            Improving the Strength of Glass Ionomers
P5    Joshua Burns          Microtensile Bond Strengths of Self-Etching and Total-Etching Adhesives
P6    Kendell Buxton        Comparative Study of Temporary Cementing Agents
P7    Julie Carnes          College of Dentistry or Private Practice: A Patient Survey
P8    Billy Cho             Six-Month Longitudinal Evaluation of Subjects With Recent Tongue Piercing
P9    Daniel Choi           The Relationship Between Dental caries and Behavior of Pre-School Children
                            Identification of Red-Fluorescing Caries-Associated Bacteria and
P10 Daniel Claman
                            Characterization of the Oral Bacterium Veillonella X042
P11 Jessica Davis
    Samuel                  Microflora Formation Around One-Stage Dental Implants –
P12
    DeAngelo                A Preliminary Report
P13 David Defay             Transverse Strength of Three Denture Base Materials
P14 Phing Dong              Stress Enhances Immune Response in Trigeminal Ganglia of HSV-1 Mice
    Randy
P15                         In-vitro Model for Characterization of NSAID Accumulation by Oral Epithelium
    Fitzgerald
    Christopher
P16
    Gamble
P17 Tobi Gbemi              Transport of Naproxen by Human Gingival Fibroblasts and PMNs
P18 Laura Geran             Representation of Bitter Tasting Chemicals in the Rat NST
    Kelly
P19                         Oral Cancer Reporting Practices of Relevant Healthcare Providers in Ohio
    Gerhardstein
P20 Erin Gross              Molecular Analysis of the Biofilm in Caries of the Primary Dentition
P21 David Gustafson         Epidemiology of Traumatic Dental Injuries to the Permanent Dentition.
P22 Cyndi Head              Regulation of NF-κB Activation by Androstenediol During Wound Healing
P23 Dustin Jacobs
                            Mechanical Properties of Three Palladium-Silver Casting Alloys for
P24 Dongfa Li
                            Metal-Ceramic Restorations
                            Assessment of Readability for 25 Pediatric Dentistry Patient Education
P25 Hsuan Li Lin
                            Materials
                            Blunted Th2 Immunological Memory Profile is Induced by Social Stress
P26 Jacki W. Mays
                            Prior to a Primary Influenza Viral Infection in Male C57 Mice.
                            Neutrophil Formylpeptide Receptor SNP 348T>C in Subjects with Aggressive
P27 Pooja Maney
                            Periodontitis
                            Mandibular Bone Mass and Geometry of C57BL/6J (B6) and
P28 Isaac Meta
                            B6.C3H-4T (4T) Mice
      Adam
P29                         Reactive Species Activation of NFκB in HNSCC
      McCormick

      Twenty-second Annual Student Research Program Scientific Session:                                9
      February 15, 2006
#   Presenter               Title
    Kelly
P30                         The Effects of Passive Stress on Irradiated Parotid Myoepithelial Cells
    Moneysmith
                            Periodonal and Peri-Implant Health: Associations in Periodontal Maintenance
P31 Patrick Nolan
                            Patients
P32 Brent Paulus            Potential Prognostic Factors for Dental Implant Failures
P33 Ellen Prochska          Dentin Adhesion: Are Fewer Steps Better?
                            Histomorphometric Analysis of Bone Supporting Screws at 6 Weeks
P34 Jahnavi Rao
                            Post-Insertion
      Thasanai
P35                         Cyclic Loading Effect on Interface Strength of Composite Onlay-like Restorations
      Roongruangphol
      Andrew
P36                         Indentation Properties of Young and Adult Canine Condylar Bone
      Rummel
P37   Kara Schafer
P38   Robert Scoresby       Fiber Reinforced Composite Pins
P39   Danen Sjostrom        Modulation of the Beta-Catenin Pathway by Biomechanical Signals in TMJ
      Heidi Snider          STAT1 and T-bet Play Distinct Roles in Determining the Outcome of Visceral
P40
                            Leishmaniasis Caused by L. donovani1.
P41 Prem                    Delivery of Transforming Growth Factor-Beta 3 (TGF-BETA3) Plasmid
    Sundaralingam           in a Collagen Gel Vehicle Delays Fusion of the Rat Posterior Frontal
                            Suture In Vivo
P42 Leslie Thomas           Restraint Stress Differentially Affects Oral and Cutaneous Wound Healing
P43 David Thurman           Histomorphometry of Mandibular Condyles in Young Canine Dogs
P44 Joseph                  The Reliability of the OQLQ in an American Population
    Whitesides
P45 Jim Ziuchkovski Assessment of the Esthetic Acceptability of Orthodontic Appliances




      Twenty-second Annual Student Research Program Scientific Session:                               10
      February 15, 2006
O1
Effect of Metal Recasting on Porcelain-Metal Bonding Using Force-to-Failure
Measurements
R. Liu1, J.A. Holloway1, W.A. Brantley1, W.M. Johnston1, T. Dasgupta2, and P.J. McCabe2,
1
  Ohio State University College of Dentistry, Columbus, USA, 2Ivoclar Vivadent, Amherst,
NY, USA

In the dental laboratory, excess alloy from each casting is commonly reused due to economic
reasons. Objectives: (1) Evaluate the porcelain bonding to three alloys (Ivoclar Vivadent): a)
Brite Gold XH (88.9Au–9.0Pt, <1% Sn, In, Ir, Fe, Li and Mn), b) W-5 (52.2Au–26.0Pd–
17.1Ag–2.7Sn, <1% Pt, In, Ir and Re, c) d.SIGN 53, 53.8Pd–34.9Ag–7.7Sn–1.7In–1.2Zn and
<1% Pt, Li, Re and Ru; (2) Investigate the effect of recasting on porcelain bonding to these
alloys. Methods: Metal strips (25 x 3 x 0.5 mm) meeting dimensional requirements in
ANSI/ADA Specification No.38 for metal-ceramic systems were prepared by torch melting and
casting, following manufacturer recommendations. IPS InLine porcelain (Ivoclar) with
dimensions 8 x 3 x 1.1 mm was applied at the center of each strip. Six metal-ceramic specimens
for each alloy were prepared for fresh casting and recasting (100% previously melted)
conditions, and loaded to failure at a crosshead speed of 1.5 mm/min. The distance between
supports was 20 mm, and the radius of the bending piston was 1 mm. The force (Ffail) was
recorded for bond failure, and the porcelain bond compatibility index (tb) was calculated.
Statistical comparisons were made using ANOVA. Results: Mean values of Ffail and tb for each
group were: Brite Gold XH fresh casting (9.0 N, 40.5 MPa); Brite Gold XH recasting (9.8 N,
44.1 MPa); d.SIGN 53 fresh casting (10.5 N, 50.4 MPa); d.SIGN 53 recasting (10.5 N,
50.4MPa); W-5 fresh casting (10.5 N, 48.3MPa); W-5 recasting (9.5 N, 43.7 MPa). There was no
significant difference (p > 0.05) for the two casting conditions or three alloys. Conclusions: The
bond compatibility index for all three alloys under both casting conditions met the ANSI/ADA
standard (≥ 25 MPa). Recasting did not adversely affect porcelain-metal bonding. Partial support
from NIDCR Grant DE10147.




Twenty-second Annual Student Research Program Scientific Session:                               11
February 15, 2006
O2
N-Acetyl-L-Cysteine Upregulates TIMP-1 and TIMP-2 Expression in Squamous Cell
Carcinoma
M. Horan, P. Pei, G. Chacon, and S. Mallery

Matrix Metalloproteinase (MMP) expression and activation is important in the progression of
oral dysplasia to squamous cell carcinoma (SCC) (Jordan, 2004). Elevated MMP-1, -2, and -9
expression is commonly observed in early stage SCC (Sheu, 2004; Samantaray, 2004), and is
predictive of SCC tumor cell aggressiveness and metastatic potential (Xu, 2003; Katayama,
2004). N-Acetyl-L-Cysteine (NAC) is a prototypic chemopreventative agent, representing a class
of thiol containing macromolecules capable of inhibiting MMP activation and potentially SSC
progression. As a potent antioxidant, NAC has the ability to alter cellular redox status, thereby
affecting the activity of redox sensitive transcription factor that regulate expression of MMPs
and their endogenous inhibitors - tissue inhibitors of metalloproteinases (TIMP). Objective: To
determine if local delivery of NAC affects the expression of MMP-1, -2, -9, and -13, and their
endogenous inhibitors TIMP-1 and TIMP-2, in SCC cells in vitro. Methods: ATCC SCC cell
lines (n=5) were stimulated with TNF-α, SIN-1, or H2O2 to upregulate MMP expression.
Concurrently, cells were treated with NAC or placebo control. Cells were harvested, total RNA
isolated, and cDNA synthesized. Relative expression of MMP-1, -2, -9, –13, and TIMP-1 and –2
mRNA was analyzed by Real-time PCR. Results: Treatment of SCC cells with NAC did not
significantly alter the expression of MMP-1, -2, -9, or -13 mRNA(p=NS, Kruskal-Wallis, Z-test).
Conversely, expression of TIMP-1 and TIMP-2 was upregulated >2fold (p<0.05, Kruskal-
Wallis, Z-test). Conclusions: These data suggest that NAC may be capable of inhibiting MMP
activation by increasing expression of their endogenous inhibitors, TIMP-1 and TIMP-2. These
experiments provide a basis for the continued development of NAC as an antioxidant-based,
chemopreventative agent in the treatment of SCC. Supported by NIDCR-F30-DEO5755,NCI-
R01-CA95901.




Twenty-second Annual Student Research Program Scientific Session:                              12
February 15, 2006
O3
Digital Removable Partial Denture Design
K. Varley, C. Machado

GUI removable partial denture design software integrated with best-practice rules of design
educates dental students approaching RPD design for the first time and reminds practicing
dentists of critical considerations. Intended for use in institutional and private practice settings,
this stand-alone application aids busy practitioners in RPD treatment planning by integrating
guidelines and indications/contraindications in each design element. The final output of the
application is a printable lab prescription of the user’s design to be sent with models for
fabrication of the RPD.

Intended to be cross-platform, the software was designed using Macromedia Flash MX on a PC
running Windows XP. Images used were edited in Adobe PhotoShop 7.0 and drawn as vector
graphics in Flash. The interface was designed for users with no specific technological expertise.
Navigation in the interface is point-and-click.

Screen Shot:




Twenty-second Annual Student Research Program Scientific Session:                                       13
February 15, 2006
The software will be evaluated for ease-of-use and educational value in two study groups:
students with no prior RPD design training and practitioners who have completed at least one
course in RPD design. Participants will be presented the same partially edentulous model and a
description of clinical findings. Participants will be asked to design a RPD for the fictitious
patient using the software. Designs from each group will be evaluated for clinical acceptability,
allowing a comparison of the groups’ designs with and without outside training. Participants
will complete a survey, including a self-evaluation of level of comfort with technology and
experience using the software. A beta version of the software will be developed considering user
feedback from study results and surveys.

The application intends to enhance RPD design educational experiences for students as well as
streamline design processes for practicing dentists. Using a digital interface that includes best-
practice rules, many designs for the same case can be evaluated and a reasonable comparison can
be assessed more easily than hand-drawn designs using textbook references.




Twenty-second Annual Student Research Program Scientific Session:                               14
February 15, 2006
O4
Metallurgical Characterization of Cast-To Implant Components from Five Companies
Y. Sanli*, S. Bhattiprolu, E.A. McGlumphy, W.M. Johnston, and W.A. Brantley

Cast-to components are commonly used in screw-retained implant restorations to produce a
precise fit. Purpose: To characterize cast-to components from five companies: Dentsply Friadent
CeraMed (Lakewood, CO), LifeCore (Chaska, MN), Nobel Biocare (Goteborg, Sweden),
Straumann ITI (Waldenburg Sweden) and Zimmer Dental (Carlsbad, CA). Methods: Three
sample components from each company were mounted in metallographic resin, sectioned into
quarters, remounted in the resin, wet-polished with alumina abrasives, cleaned by ultrasonic
agitation in distilled water, etched with aqua regia solutions, and carbon-coated for scanning
electron microscope (SEM) observation. Secondary and backscattered electron images were
collected to investigate the variations in surface topography and composition, respectively.
Energy-dispersive x-ray analyses (EDS) were performed on carbon-coated samples using an
Oxford spectrometer coupled to the SEM. Overall Vickers hardness (500 g load) and the Vickers
hardness of the two major microstructural constituents (10 g load) were measured. The EDS
composition data and Vickers hardness data were compared using ANOVA and the Ryan-Einot-
Gabriel-Welsch multiple range test (α = 0.05). Results: Implant components were composed of
two distinctive parallel-band constituents having different concentrations of gold, palladium, and
platinum. Trace concentrations of iridium were also found in the components. Elemental
compositions of the two constituents were significantly different for each implant component and
all five products. The palladium content was very similar for all products, with greater variation
in the gold and platinum contents. The gold-rich constituent in each product was found to have
lower Vickers hardness. At high SEM magnifications, each constituent appeared contain two
phases. Conclusions: The elemental compositions, microstructures and Vickers hardness of the
five cast-to implant components were similar. Because both major microstructural constituents
principally contain gold, palladium and platinum, these noble cast-to implant components should
be compatible with noble metal casting alloys. Supported by NIDCR Grant DE10147 and
Cukurova University of Turkey.




Twenty-second Annual Student Research Program Scientific Session:                              15
February 15, 2006
O5
Androstenetriol Modulates Apopotosis by Regulating the Expression of Bcl-2
Tyler Robb, Amy Hufnagle, and David A. Padgett

Efficient wound healing is a necessary part of an organism’s ability to survive in the
environment in which it lives. Cytokines, such as TNF-α, produced immediately after injury, are
essential to facilitate wound closure as they initiate the early inflammatory phase of repair.
During this inflammatory phase of healing, contaminating bacteria are removed, and non-viable
cells are debrided from the margins of the wound. TNF-α is important to both of these processes.
Of relevance to this study is the fact that during debridement of the damaged tissue, TNF-α
induces fibroblasts in the margin of the wound to undergo apoptosis. If too many fibroblasts are
induced to undergo programmed cell death, wound healing and new tissue deposition would be
impaired. Previous data from this laboratory illustrated that the steroid hormone androstenetriol
(AET) accelerated the early phase of wound closure. Therefore, we hypothesized that AET
would prevent TNF-α-mediated fibroblast apoptosis. To test this hypothesis, the L929 fibroblast
cell line was first tested for its sensitivity to TNF-α mediated cell death. An LD50 dose of TNF-α
was determined by incubating cultures of 2.0 x 105 L929 fibroblasts with serial dilutions (0.06 –
250,000 pg/ml) of TNF-α overnight. Cell viability was assessed using crystal violet staining read
at an absorbance of 595nm. Once the LD50 dose was determined, cultures of cells were treated
with dilutions of AET (5.0 x 10-6M to 5.0 x 10-9M) for one hour prior to overnight co-incubation
with the LD50 dose of TNF-α. The data revealed that pre-treatment with AET at 1.0 x 10-7M dose
prevented TNF-α mediated apoptosis. Finally, we sought to determine a potential mechanism by
which AET functioned. Because the protein Bcl-2 has been shown to interfere with TNF-α-
mediated cell death, we used real-time PCR to determine whether AED influenced the
expression of Bcl-2.Cultures were treated as before. After a two-hour incubation, RNA was
isolated using Trizol, cDNA was synthesized, and Real Time PCR was performed with custom
probes designed to amplify the cDNA for Bcl-2. The data showed that when cells were
pretreated with AET, transcription of Bcl-2 was enhanced as compared to the TNF-α treated
control. Together, these data support our hypothesis and show that AET rescued fibroblast cells
from TNF-α-mediated apoptosis in a Bcl-2 dependent manner.




Twenty-second Annual Student Research Program Scientific Session:                              16
February 15, 2006
O6
Androstendiol Inhibits Influenza Virus Replication in Human Respiratory Epithelial Cells.
Peter Lovejoy, Scott Wray, and David A. Padgett

Even in years when not threatened by an avian influenza pandemic, human influenza viruses
inflict significant morbidity and mortality upon the world’s population. In the United States
alone influenza causes 40,000 deaths a year; the annual outbreaks are accompanied by staggering
medical costs of approximately 100 billion dollars a year. In an effort to limit disease, vaccines
are employed that “teach” the immune system to attack the surface hemagglutinin and
neuraminidase proteins of the influenza virus. Unfortunately, because of the inherent antigenic
shift and drift of these viral proteins, vaccines have to be reformulated and re-administered each
year. The logistics and expense of vaccinating the world’s population every year is prohibitive.
Therefore, it would be advantageous to develop therapies that would combat the virus without
necessitating the development of antigen-specific memory directed at the variable hemagglutinin
and neuraminidase molecules. We have previously shown that the androgen hormone,
androstenediol (AED), increased the survival of mice infected with the human influenza virus
regardless of their vaccination status. In the current studies we tested the hypothesis that AED
would alter a host cell’s response to an influenza infection and limit viral replication without
consideration for the highly variable surface proteins. To test this hypothesis, virus replication
was assessed in the influenza-permissive A549 human lung epithelial cell line treated with or
without AED. 5x106 A549 cells were treated with 5x10-6 M AED for 24 hours before infection
with 3.75 HAU of influenza A/PR8. After infection for 24 hours, cultures were harvested, RNA
was isolated using Trizol, and cDNA was synthesized using reverse transcription. As a measure
of viral replication, real-time PCR was performed with custom probes designed to amplify the
cDNA for the late viral gene, M1. The data showed that AED treatment reduced M1 gene
expression by 50% as compared to untreated cultures. In addition, the data showed that AED
treatment caused a two-fold increase in Bcl-2 gene expression by the A549 human epithelial cell.
Elevated Bcl-2 expression indicated that the A549 cells were rendered resistant to influenza-
induced programmed cell death which is necessary to release infectious progeny virus. Together,
these data support our hypothesis and indicate that AED treatment can limit influenza viral
replication in human lung epithelium.




Twenty-second Annual Student Research Program Scientific Session:                              17
February 15, 2006
O7
In Vitro Evaluation of Three Designs of Implant Placement for Supporting Maxillary
Overdentures
B. Frandsen, E. Sanchez, G. Chacon, C. Machado




Twenty-second Annual Student Research Program Scientific Session:                    18
February 15, 2006
O8
Physical Properties of Cerium-doped Tetragonal Zirconia (10mins)
K.C. Shah, I. Denry, and J.A. Holloway

Objectives: investigate the effect of cerium salts solutions on the phase stability, microstructure
and flexural strength of tetragonal zirconia (3Y-TZP). Methods: cylindrical blanks were
produced by cold isostatic pressing. The blanks were sectioned into disks (2mm thick, 25mm in
diameter, n=16 per group) and infiltrated with cerium acetate (CA) or cerium chloride (CC)
solutions at 1, 5, and 10 wt.%. As-pressed disks were used as controls. The disks were sintered at
1350°C for 2 hours. The density was measured by Archimedes' method. The crystalline phases
were analyzed by XRD on bulk, as-sintered specimens. The microstructure was investigated by
SEM. The biaxial flexural strength was determined using a ball on ring-of-balls fixture at a
cross-head speed of 0.5mm/min. Results: Anova and Tukey's test showed that the mean density
of the infiltrated groups was not significantly different than that of the control group
(6.070±0.007g/cm3) except for the group infiltrated with CC10% (p=.001)
(6.096±0.011g/g/cm3). XRD of the as-sintered specimens revealed the presence of tetragonal
zirconia exclusively. There was a significant increase in grain size (p≤ .045) for the groups
infiltrated with CA10% (0.350±0.031µm) or CC10% (0.357±0.035µm) compared to the control
group (0.318±0.029µm). There was no significant difference in mean biaxial flexural strength
between CA1% (1101.8±135.5MPa) or CA5% (915.1±85.9MPa) groups and the control group
(1087.5±173.3MPa). The mean flexural strength of all other groups was significantly lower than
that of the control group (p≤ .033). The CC10% group exhibited a significantly lower mean
flexural strength (274.7±67.3MPa) than all other groups (p=.001). The mean flexural strength
decreased linearly (R-square>.95) with increasing concentration for both cerium salts.
Conclusion: infiltration with cerium salts did not effect the phase stability of 3Y-TZP but
increased grain size and significantly decreased the flexural strength at the highest
concentrations. Supported by the Academy of Prosthodontics Foundation.




Twenty-second Annual Student Research Program Scientific Session:                                19
February 15, 2006
O9
Aged Mice are More Susceptible to Defeat-Induced Hyperinflammation than Young Adult
Mice
Steven G. Kinsey, Michael T. Bailey, John F. Sheridan, and David A. Padgett

Recent evidence suggests that age-related dementias, including Alzheimer’s disease, are
exacerbated and caused in part by unregulated inflammation in the brain. As animals age, their
immune systems become less effective at fighting viral and bacterial infections; this is termed
immunosenescence. Immunosenescence is characterized by weakened adaptive immunity and a
lack of control over proinflammatory cytokine production. Paralleling the effects of aging,
behavioral stress can also have similar effects on immune function. Furthermore, previous
research has suggested that aging and stress interact, causing exaggerated losses in immune
regulation and increased mortality due to infectious diseases, including influenza. Therefore, the
purpose of this study was to measure the interactive effects of age and the stress of repeated
social defeat on immune function with particular regard to proinflammatory cytokine production.
Male mice aged either 2 or 14 months were subjected to repeated social defeat by an aggressive
conspecific. Mice were defeated during six consecutive daily trials, each lasting 30 minutes.
Control mice were left undisturbed in their home cages during defeat sessions. One day after the
last defeat trial, spleens were harvested. Leukocytes were isolated from the spleens and cultured
with lipopolysaccharide (LPS, a bacterial endotoxin) to stimulate proinflammatory cytokine
production. Cultures of cells were incubated with the stress hormone corticosterone to measure
sensitivity to hormone regulation. In addition, white blood cell populations were identified by
flow cytometry. Statistical comparisons were made using ANOVA, and significance was set at p
< 0.05. There was an age effect: as after stimulation with LPS, cells from aged mice produced a
greater quantity of the proinflammatory cytokines IL-6 (interleukin-6) and TNF (tumor necrosis
factor) than did the cells from young adult mice. There was a stress effect: repeated social defeat
enhanced proinflammatory cytokine production in both age groups. There was an interaction
between age and stress: stress caused a decrease in corticosterone sensitivity, and this effect was
greatest in the cells from aged mice. As shown previously, age and stress both caused a decrease
in immune regulation. Aging caused the immune profile to skew toward inflammation, and older
mice were less responsive to stress-activated hormonal regulation than younger mice. Thus, two
regulatory systems appear to be altered in aged mice, possibly increasing susceptibility to disease
and uncontrolled inflammation.




Twenty-second Annual Student Research Program Scientific Session:                               20
February 15, 2006
O10
Osteoprotegerin Inhibits Periodontal Alveolar Bone Loss in Susceptible Animals
H.A. Alzoman, D.N. Tatakis

Objectives: HLA-B27 transgenic (TG) rats have been shown to experience accelerated alveolar
bone loss (ABL), compared to control (WT) F344 rats. The purpose of this study was to examine
the potential effect of osteoprotegerin (OPG) on both the naturally occurring ABL in this model
and on the possible ovariectomy-induced ABL.
Methods: 46 female, 7-8 week old, TG rats and 52, age- and sex-matched WT rats were used.
Half of the TG and WT rats were ovariectomized (OVX) and half were sham-ovariectomized
(SHAM). Animals were then randomized to receive either vehicle (PBS) or recombinant human
osteoprotegerin (rhOPG, Amgen). rhOPG (5 mg/kg) or PBS was administered twice weekly via
SC bolus injection and animals were sacrificed at 6 or 9 months of age. After sacrifice, defleshed
heads were stained to locate the cementoenamel junction and ABL was measured as exposed
molar root surface area (mm2) as previously described (J Periodontol 2000;71:1395-1400).
Blinded measurements were performed using a computer assisted image analysis system.
Results: Both OVX and SHAM TG rats experienced greater ABL than corresponding WT
controls (p<0.0001). Animals sacrificed at 9 months of age had greater ABL than those
sacrificed at 6 months of age (p<0.001). rhOPG significantly reduced ABL in both TG and WT
rats (p<0.001). However, there was no significant difference in ABL between OVX and SHAM
animals (p>0.05). Multiple regression analysis indicated that only strain (TG, WT), age at death,
and treatment (rhOPG, PBS) were significant factors for ABL.
Conclusions: Results are consistent with previous reports of increased ABL in TG rats.
Ovariectomy does not compound the ABL observed in this model or in WT rats. The significant
reduction in ABL by rhOPG suggests that rhOPG merits further study as a possible treatment
modality for inhibition of periodontal bone loss in humans.
Supported by OSU COD




Twenty-second Annual Student Research Program Scientific Session:                               21
February 15, 2006
O11
Effects of Porcelain-Firing and Annealing Heat Treatments on Palladium-Silver Alloys
D. LI1, X. HU1, S.B. ALAPATI1, W.A. BRANTLEY1, R.H. HESHMATI1, T. DASGUPTA2,
and P.J. MCCABE2, 1 Ohio State University College of Dentistry, Columbus, USA, 2
Ivoclar Vivadent, Amherst, NY, USA

Palladium-silver casting alloys have become more popular recently for metal-ceramic
restorations because of the lower cost of palladium than gold. Objective: To study the
microstructures and variation in Vickers hardness during simulated porcelain-firing and
isothermal-annealing heat treatment in three Pd–Ag alloys (Ivoclar Vivadent): (a) IS 64, 59.9Pd–
26.0Ag–7.0Sn–2.8Au–1.8Ga–1.5In; (b) d.SIGN 59, 59.2Pd–27.9Ag–8.2Sn–2.7In–1.3Zn; (c)
Aries, 63.7Pd–26.0Ag–7.0Sn–1.8Ga–1.5In (wt%). Methods: Specimens meeting dimensional
requirements in ADA Specification No. 5 were prepared using torch melting and recommended
dental laboratory techniques. The specimens were sectioned in the gauge region into test sample
disks with 1 mm thickness, using a slow-speed, water-cooled diamond saw. Except for as-cast
samples, all other samples were subjected to either of two types of heat treatment: (1) the
simulated porcelain firing process, including initial oxidation and subsequent six firing cycles
recommended for IPS Classic dental porcelain (Ivoclar Vivadent); (2) isothermal heat treatments
for 30 minutes from 450° to 950°C with intervals of 50°C. After standard metallographic
procedures, microstructures were examined using an SEM. Bulk Vickers hardness and
microhardness of single phase or multiphase regions were measured using loads of 1 kg and 10
g, respectively, with dwell time of 30 seconds. Results: During simulated porcelain-firing heat
treatment, the Vickers hardness of all three alloys greatly decreased after initial oxidation, along
with evident microstructural changes. After each of the subsequent porcelain firing cycles, the
Vickers hardness remained nearly constant even though there was variation in the
microstructures. The Vickers hardness and microstructures varied substantially with individual
annealing temperatures, with highest hardness around approximately 500°C for IS 64, 550°C for
Aries, and 650°C for d-SIGN 59. Conclusions: The microstructures and hardening behavior for
these three Pd–Ag alloys are considerably different. Supported by NIDCR Grant DE10147 and
Ivoclar Vivadent.




Twenty-second Annual Student Research Program Scientific Session:                                 22
February 15, 2006
O12
Investigation of Transformations in Used and Heat-Treated Nickel-Titanium Endodontic
Instruments
S.B. Alapati1, W.A. Brantley1, S.R. Schricker1, J.M. Nusstein1, U.-M. Li2, and T. Svec3,
1
  Ohio State University -, Columbus, USA, 2National Taiwan University, Cardinal Tien
Hospital, Taipei, Taiwan, 3University of Texas Dental Branch at Houston, USA

Nickel-titanium rotary instruments may exhibit reversible transformation from the parent
austenitic structure (A) to the martensitic structure (M) under stresses during preparation of
curved root canals. Such transformations might have fundamental consequences for clinical
performance of these instruments. Temperature-modulated differential scanning calorimetry
(TMDSC) provides an ability to differentiate overlapping transitions that is not possible with
conventional DSC. Objective: Investigate transformation temperature ranges (TTR) in NiTi
rotary instruments after clinical use, mechanical bending, and heat treatment. Methods: ProFile
(Dentsply), ProTaper (Dentsply) and Liberator (Miltex) instruments were selected. ProFile and
ProTaper instruments subjected to controlled clinical use and discarded instruments were
compared to as-received instruments. All three groups of instruments were also subjected to 90°
bending, and heat-treated for 15 minutes in a nitrogen atmosphere at 400°, 500° and 600°C. As-
received, used, and heat-treated instruments were cut into 3 or 4 segments. TMDSC analyses
(DSC Q100, TA Instruments) were conducted between –80° and 100°C, using a linear heating
and cooling rate of 2°C per minute and an oscillation amplitude of 0.318°C with a period of 60
seconds. Nitrogen was used as the purge gas. Results: Clinically used instruments and bent
instruments showed minimal change in TTR and enthalpy for overall transformation between the
(A) and (M) structures. The presence of the intermediate R–phase was minimally evident with
as-received and bent test specimens, and may be more apparent after heat treatment. Low-
temperature martensitic transformations, resolved on the nonreversing heat flow curves, were not
present on the reversing heat flow curves and were more apparent for heat-treated specimens
than bent specimens. Conclusions: Heat treatment results in loss of clinical shape memory in the
NiTi instruments, and allows for pre-curving. Further research is needed to compare cutting
efficiency of heat-treated and as-received NiTi rotary instruments. Dentsply Tulsa Dental
donated instruments for this study.




Twenty-second Annual Student Research Program Scientific Session:                             23
February 15, 2006
P01
Success of Mandibular Immediate Load Hybrid Dentures
P.H. Allen, T. El-Gendy

Immediate Loading was thought to be a viable method of restoring edentulous patients with
implant supported hybrid dentures. The purpose of this study was to evaluate the success of
immediate load cases that were done since July 2001 via post entry chary review at the Ohio
State University. Different implants have been placed at the College of Dentistry in the
following clinics: Oral Surgery and Periodontology. These have all been subsequently restored
in the Implant Clinic. 58 mandibular hybrid systems met the criterium for this study
incorporating 283 total implants. Only 2 of the hybrid systems suffered complete failure
resulting in a 96.6% success rate. 13 totat implants failed resulting in a 95.4% success rate. 4
hybrid systems had implant failure that was not associated with hybrid system failure. Restoring
patients with an immidiately loaded hybrid prostheses is a successful method of treatment for the
edentulous mandible.




Twenty-second Annual Student Research Program Scientific Session:                              24
February 15, 2006
PO2
Acquisition by Children of Gram-Positive Bacteria Associated with Periodontitis
A. L. Beroske, A. L. Griffen, E. J. Leys

Objective:
The purpose of this study was to investigate the acquisition of three gram-positive anaerobes that
were recently found to be associated with periodontitis. The presence of Filifactor alocis,
Peptostreptococcus BS044, and Peptostreptococcus CK035 was measured in children using a
cross-sectional study design to evaluate the relationship between age and acquisition.

Methods:
The colonization status of 222 children between the ages of 0 and 18 was determined. Samples
were collected from each child by placing paper points in the mesial sulcus of every tooth. The
DNA was isolated from the combined paper points. A PCR assay was used to detect Filifactor
alocis and the uncultivated phylotypes BS044 and CK035. A universal amplification was
performed on each sample followed by species-specific amplifications targeting the 16S and
intergenic spacer region between the 16S and 23S ribosomal genes. The samples were analyzed
for the presence of the target bacteria by gel electrophoresis on a 1% agarose gel. All samples
were amplified and scored a second time. If results were not in agreement, the amplification was
repeated.

Results:
F. alocis was detected in 17% of the samples. BS044 and CK035 were more common, and were
detected in 53% and 57% of the samples respectively. Increasing prevalence was highly
significantly related to increasing age of Filifactor alocis, BS044, and CK035. The logistic
regression P-values for F. alocis, BS044, and CK035 were 0.0004, 0.003, and <0.0001
respectively. In contrast, Porphyromonas gingivalis was previously found in 36% of these same
subjects and the prevalence did not increase with increasing age.

Conclusion:
The prevalence of Filifactor alocis, Peptostreptococcus BS044, and Peptostreptococcus CK035
increased with increasing age. This is in contrast to the prevalence of Porphyromonas gingivalis,
which has been shown to remain constant among subjects of all ages.

Supported by NIH DE10467.




Twenty-second Annual Student Research Program Scientific Session:                               25
February 15, 2006
PO3




Twenty-second Annual Student Research Program Scientific Session:   26
February 15, 2006
PO4
Improving the Strength of Glass Ionomers
Kyle D. Bogan and Dr. Scott Schricker

The objective of this project is to increase the overall strength of glass ionomer through the use
of block copolymers. The alteration of polymer architecture as a means to improve the
properties of glass ionomers is an extremely new approach in this research area. In fact, this
method for improving glass ionomers is essentially absent from the literature with a few minor
exceptions. Thus, the synthesis of the block copolymer for this GI system was modeled from the
synthesis conducted by Lai, Filla, and Shea [2]. The catalyst S,S’-Bis(,’-dimethyl-’’-acetic
acid)-trithiocarbonate was synthesized by following the procedure provided by Lai. The catalyst
was used to construct a block copolymer from acrylic acid and hydroxyethyl methacrylate
(HEMA). Solutions of the synthesized block copolymers were formulated with commercially
available filler. The resulting glass ionomer cement was then evaluated using flexural tests to
determine the effect of the block copolymers on the overall strength of the material.
A tri-block copolymer (AA-HEMA-AA) and a di-block copolymer (AA-HEMA) of 2:1 acrylic
acid and HEMA, as well as three controls (commercially available Fuji IX, poly-AA block, and a
random block copolymer) were formulated. There were no significant differences in peak load,
break load, or modulus between the experimental and control samples. See Figure 1. In the
ideal system, the acid block would etch the glass while the HEMA block would form the matrix.
It is possible that the matrix is not strong enough. The HEMA could be increasing the solubility
of the glass ionomer contributing to its weakness. Therefore, the next step in this ongoing
project is to formulate block copolymers using a replacement such as methyl methacrylate for
HEMA, and to test block copolymers of different lengths.

Sample                  Peak Load (N)                  Break Load (N)      Modulus (GP)
Fuji IX Control         14.72 +/- 2.84                 14.55 +/- 3.03      4.64 +/- 2.26
Acrylic Acid Block      16.72 +/- 3.66                 16.65 +/- 3.65      6.07 +/- 0.60
Random Block            13.48 +/- 1.75                 13.42 +/- 1.76      6.31 +/- 0.52
Tri-Block               8.83 +/- 3.06                  8.73 +/- 3.01       4.84 +/- 0.62
Di-Block                10.98 +/- 1.72                 10.78 +/- 1.74      5.60 +/- 0.55
Figure 1: Experimental Fracture Test Results




Twenty-second Annual Student Research Program Scientific Session:                               27
February 15, 2006
PO5
Microtensile Bond Strengths of Self-Etching and Total-Etching Adhesives
J. Burns, R. Kerby, L. Knobloch, D. Gailey, R. Seghi, and W.M. Johnston

Objective: The mean microtensile bond strength (micro-TBS) of composite resin bonded to
human dentin was evaluated utilizing five light cure self-etching adhesive systems (Clearfil SE
[CSE], G-Bond [GB], iBond [IB], Xeno [XS] and Optibond Solo Plus Self-Etch [OSE]) and two
light cure total-etch adhesive systems (Prime & Bond NT [PB] and Optibond Solo Plus [OP]).
Methods: Forty-two freshly extracted non-carious human third molars were sectioned
horizontally to expose a flat hydrated dentin surface. Composite resin (Herculite XRV) cylinders
were then bonded incrementally using the seven bonding agents according to manufacturer
specifications. Each bonded tooth specimen was longitudinally sectioned with a low-speed
diamond saw in an “X” and “Y” direction to produce “sticks” with a square cross-sectional
nominal bond area of 1.4 mm2. Specimens were then randomly divided into two groups: Group
I: Bonded stick specimens (n=20) were stored in distilled water at 37°±2°C for 7 days, during
which time they were subjected to thermocycling in distilled water baths at 5°C and 55°C for a
30 second dwell time per bath and 1500 cycles. Group II: Stick specimens (n=20) were
similarly stored but thermocycled in 0.001 M lactic acid (pH 4.5) to simulate plaque-acid
conditions. Results: Mean micro-TBS values (MPa) with standard deviations (SD) are listed
below:
Adhesive              Distilled H2O           Lactic Acid (pH 4.5)
OSE                   31.5 (12.0)             26.0 (8.8)
IB                    24.8 (9.6)              17.8 (8.5)
CSE                   24.7 (9.0)              20.8 (11.3)
XS                    24.5 (8.1)              14.9 (6.9)
GB                    19.2 (7.9)              19.7 (6.6)
PB                    35.7 (13.2)             23.2 (10.0)
OP                    13.0 (5.8)              9.1 (4.2)

General linear model (p<0.05) and REGW Multiple Range Test (p<0.05) showed significant
differences between the mean micro-TBS bond values of the various bonding agents within and
between both groups. PB total-etch and XS self-etch adhesive exhibited significant reduction in
micro-TBS under acidic conditions. Weibull distribution for survival analysis resulted in moduli
(m) ranging from 2.03-3.7. Wald chi-square test of Weibull distribution showed significant
differences between acid and non-acid treated groups (p<0.001). Conclusion: Some total-etch
and self-etch adhesive systems may exhibit a significant reduction of bond strength under acidic
conditions.




Twenty-second Annual Student Research Program Scientific Session:                             28
February 15, 2006
PO6
Comparative Study of Temporary Cementing Agents
K. Buxton, W. M. Johnston, C. Machado

Background: TempBond® Clear (Kerr) is a popular and well-accepted temporary cement
which often shows undesirable effectiveness in retaining a restoration. Life® (Kerr) is used as a
calcium-hydroxide base, yet some dentists have experienced better results with this material as a
cement in terms of quality of retention. However, there is a lack of studies proving the retentive
capabilities of this cement.
Objective: The purpose of this project was to compare the retentive capacity of Life®, a
calcium-hydroxide base, as a temporary cement, with a commonly used cement, TempBond®
Clear.
Methods: 20 extracted third molars were prepared for a standard MCC restoration. Provisional
crowns were constructed for each using Jet® acrylic resin. 10 crowns were randomly cemented
with Life® and 10 with TempBond® Clear. An orthodontic wire was fastened to each crown
and shaped with a retentive loop for attachment to an Instron® mechanical testing machine. The
cemented temporary crowns were removed with the Instron® universal testing machine at 0.5
mm/min. Mean and standard deviations of the force required to remove the crown were
calculated.
Results: Mean separation force for TempBond® Clear equaled 21.1 N and 47.8 N for Life®.
Welch’s ANOVA analysis showed that differences in the retentive ability of the two samples
were significant (P < .001).
Conclusions: Life® exhibited better retentive abilities than TempBond® Clear. Life® may
provide dentistry with a more effective temporary cement that also has the beneficial qualities of
a calcium-hydroxide base.




Twenty-second Annual Student Research Program Scientific Session:                               29
February 15, 2006
PO7
College of Dentistry or Private Practice: A Patient Survey
J. Carnes, M.P. Carr, P. Gardner

Colleges of Dentistry (COD) and Dental Hygiene Programs (DHP) rely on patients to help
educate students and graduate competent dental professionals. In this era of competition for
patients, consumer awareness and customer satisfaction, COD/DHPs must understand and cater
to the needs of consumers to attract more patients and retain its existing patient population. It is
important to understand why consumers choose a COD/DHP versus private practice and
capitalize on these features. Objectives: The objectives of this study are to evaluate reasons why
patients chose a COD/DHP and to assess patient satisfaction with their services. Methods:
Patients at the Ohio State University COD, scheduled with first and second year dental hygiene
students were randomly selected to complete a survey regarding why they chose the COD/DHP
and to rate their experiences via a 5-point Likert scale. Results: Forty-seven subjects completed
the survey (24 male, 23 female; mean age 49.5 yrs.) 55% of subjects chose the COD/DHP due to
cost of dental treatment and 21% thought their care would be more thorough and would receive
better treatment than in private practice. Subjects stated they received good to excellent care and
99% would recommend the COD/DHP for oral healthcare needs. One way ANOVA showed no
significant difference in the level of satisfaction between males and females and Spearman's
Correlation showed moderate correlation (r= 0.263) between age and satisfaction but no
correlation between educational level and satisfaction. Conclusions: The majority of patients
attended the COD/DHP for financial reasons and perception of better care. Subjects surveyed
were very satisfied with their experience at the COD/DHP. Satisfied patients are more likely to
be compliant with their oral health, use services of the COD/DHP on a regular basis and are a
source of referrals.




Twenty-second Annual Student Research Program Scientific Session:                                 30
February 15, 2006
PO8
Six-Month Longitudinal Evaluation of Subjects with Recent Tongue Piercing
W.J. Cho, D.N. Tatakis

Objectives: The purpose of this longitudinal observational trial was to evaluate the process and
factors that contribute to the development and progression of gingival recession and tooth
chipping in subjects wearing tongue jewelry. Methods: A 6-month longitudinal trial was
conducted on 23 young adults (mean age: 19.7) with recent (< 6 months) tongue piercing. At
baseline, subjects completed a questionnaire and were examined for tooth chipping (full mouth)
and gingival recession (lingual of 6 mandibular anterior teeth). At 2 and 6 months, exams were
performed to determine changes in prevalence and/or severity of tooth chipping and gingival
recession. Independent variables were factors such as time of wear, length of barbell, incisor
crown form, smoking status, reported occurrence and daily frequency of barbell hitting gingiva
and teeth. Results: Four subjects presented with gingival recession at baseline; No factor was
significantly associated with baseline gingival recession. Ten subjects with or without gingival
recession at baseline experienced increased recession depth at 6 months; 60% of these subjects
reported hitting their mandibular gingiva and 70% wore longer (>17 mm) barbell, compared to
15% and 8%, respectively, of the subjects who did not experience increased/new recession
(p<0.05 and p<0.01, respectively, Chi-square). Eight subjects had an increased number of teeth
affected by recession at 6 months, compared to baseline; 63% of these subjects reported hitting
their lower gingiva, 50% reported hitting the lower gingiva greater than 2 times a day and 75%
wore longer barbell, compared to 20%, 7%, and 13%, respectively, of the subjects who did not
experience an increased number of involved teeth (p<0.05, p<0.025, and p<0.01, respectively,
Chi-square). No factor was significantly associated with increase in tooth chipping.
Conclusions: Hitting the gingiva with the jewelry at a frequency greater than 2 times a day and
wearing longer barbell are factors associated with the development and/or progression of
gingival recession in young adults with recent tongue piercing.
Supported by the OSU Section of Periodontology




Twenty-second Annual Student Research Program Scientific Session:                              31
February 15, 2006
PO9
The Relationship Between Dental Caries and Behavior of Pre-School Children
Dr. Casamassimo, Dr Oueis, Daniel Choi




Twenty-second Annual Student Research Program Scientific Session:            32
February 15, 2006
P10
Identification of Red-Fluorescing Caries-Associated Bacteria and Characterization of the
Oral Bacterium Veillonella X042
D.B. Claman, E.J. Leys, and A.L. Griffen

Bacteria in sites of active caries have been observed to fluoresce red when excited by blue light
at approximately 410 nm. This fluorescence may be useful for clinical diagnosis. One
fluorescing bacteria, the previously uncultivated Veillonella X042, is one of the most prevalent
bacteria in the gingival sulcus.

 Objectives: The purpose of this study was to identify bacteria from carious lesions that produce
red fluorescence, and to characterize the red fluorescing Veillonella X042 a previously
uncultivated species.
 Methods: Samples of oral bacteria taken from healthy and carious sites were grown
anaerobically on blood agar. They were exposed to a high intensity blue light and observed
through a yellow filter to allow the identification of red fluorescing colonies. DNA was isolated
from individual colonies and 16S genes were sequenced to identify species. Oral biofilm
samples were collected and grown anaerobically on Brucella Blood Agar. One previously
uncultatived species, Veillonella oral clone X042, was selected for further characterization. The
dnaK gene was sequenced for further phylogenetic comparison with other Veillonella species.
Metabolic tests were carried out to determine chemical and physical properties and compare
them with closely related bacteria.
 Results: The amount of fluorescing material reached a peak at about 2 days in culture and
decreased to undetectable levels after approximately 7 days. A larger proportion of red
fluorescing bacteria were observed in samples collected from caries sites than from healthy sites
(60% versus 10%), although the small sample size did not permit statistical analysis. The
production of fluorescing material was accelerated by supplementing the media with a 33%
solution of glucose. The addition of acid or base to the media had no effect. Species were
identified for 25 colonies from 4 subjects by sequencing the 16S genes. The most prevalent
fluorescing bacteria were Veillonella, the majority of them unnamed phylotypes. Unnamed
Prevotella phylotypes were also common. Eight other species representing a phylogenetically
diverse group of bacteria were found at low levels. Veillonella X042, found among the
fluorescing bacteria, was of particular interest. Veillonella X042 grew on Brucella Blood Agar
plates. Growth was best between 48 and 72 hours post-plating in anaerobic conditions. Colonies
were translucent, white to white-yellow, shiny and entire. Bacteria are gram-negative bacilli.
Metabolic tests were consistent with those of other members of the Veillonella genus.
Sequencing the 16S ribosomal gene and the heat shock protein dnaK gene placed Veillonella
X042 phylogenetically between Veillonella dispar and Veillonella parvula, being more closely
related to Veillonella parvula.
Conclusions: A variety of oral species can produce red fluorescence, and they appear to be more
commonly found in caries active sites than in healthy sites. The most common bacteria observed
were unnamed species from the genera Veillonella and Prevotella. Veillonella X042, found
among the fluorescing bacteria, is associated with periodontal health. It is closely related to two
species of the genus Veillonella: V. dispar and V. parvula. Supported by NIH DE016125 and
Inspektor Research Systems



Twenty-second Annual Student Research Program Scientific Session:                                   33
February 15, 2006
P11




Twenty-second Annual Student Research Program Scientific Session:   34
February 15, 2006
P12
Microflora Formation Around One-Stage Dental Implants - A Preliminary Report
DeAngelo S, Kumar P, Tatakis D, Leblebicioglu B

Background: Limited information is available on initial bacterial colonization of dental
implants. This study aims to determine the characteristics of newly forming microflora around
one-stage implants.

Materials and Methods: 11 periodontally healthy patients (7 males, 4 females, mean age 4816
years) needing single implant were included. Exclusion criteria were antibiotic uptake within 3
months or simultaneous guided bone regeneration at implant site. Subgingival plaque samples
were obtained around adjacent teeth and implant prior to and at 2, 4, 8, 12 weeks post-
operatively around implant and adjacent teeth. Polymerase Chain Reaction (PCR) technique was
used to detect specific microorganisms. Clinical evaluation included probing depth, bleeding on
probing and, width and thickness of keratinized gingiva.

Results: No early healing complications were noted. Fusobacterium nucleatum was present in
9 patients prior to surgery and continued to be a part of the flora around natural teeth during 12
weeks. Four patients had F.n. around implant by week 2 and six by week 12. Detection of
Porphyromonas gingivalis, Provetella intermedia, Tanerella forsythia and Treponema denticola
was rare. Bacteria were not detected in internal part of implant body.

Conclusion: The rate of specific bacterial growth around implants is slower than around teeth.
Further studies are necessary to better establish the rationale for post-operative care of one-stage
implants.




Twenty-second Annual Student Research Program Scientific Session:                                35
February 15, 2006
P13
Transverse Strength of Three Denture Base Materials
D. Defay1, C. Machado1, and J.M. Uribe2
1
  Ohio State University, Columbus, USA, 2 Prodenco Group Dental Laboratories, Sioux
City, IA, USA

A major concern in dentistry is the fracture resistance of polymers used to make dentures. It is
of great interest to know if these polymerized dentures are resistant to forces that have the
potential of fracturing or permanently deforming them. Eclipse® is a relatively new denture
base material. In evaluating this new material it is important to discover its physical properties
in comparison to commonly used denture base materials. Objective: The purpose of this study
was to evaluate the transverse strength of the new Eclipse® (Dentsply Trubyte) denture base
material in comparison with the widely used Lucitone 199® (Dentsply Trubyte) and Triad
VLC® (Dentsply Trubyte) materials. Methods: Ten samples (50mm x 25mm x 2.5mm) of each
material were tested using a three point bending flexural test. The samples were polished to 320
grit SiC paper. The test was performed on an Instron® universal testing machine (Canton, MA).
The support span was set at 40mm, and the specimens were loaded until failure. Mean and
standard deviations of transverse strength were calculated for each group. Data were analyzed
using JMP 5.1.2 (SAS, Cary, NC). Results: Transverse strength values for each group, mean
(standard deviation): Eclipse® 116.13 (17.7) MPa, Lucitone 199® 87.12 (8.1) MPa, Triad
VLC® 57.96 (7.3) MPa. A one-way analysis of variance indicated there were significant
differences in transverse strength between the three groups (p < 0.0001). A Tukey HSD post hoc
test indicated that all three groups differed significantly. Conclusion: Within the limits of this in
vitro testing Eclipse® would appear to have the highest transverse strength among the materials
tested.




Twenty-second Annual Student Research Program Scientific Session:                                  36
February 15, 2006
P14
Stress Enhances Immune Response in Trigeminal Ganglia of HSV-1 Mice
P.M. Dong, M.T. Bailey, D.A. Padgett, and J.F. Sheridan

OBJECTIVES: Monocytes/macrophages are the predominant infiltrating cell in the trigeminal
ganglia (TG) 3-7 days after a primary infection. They produce anti-viral cytokines needed to
reduce viral replication. Previous research from our laboratory demonstrated that social
disruption stress (SDR) enhances the trafficking of monocytes/macrophages from the bone
marrow to the spleen, and increases pro-inflammatory cytokine production both in vitro and in
vivo. The impact of SDR on the functioning and trafficking of these cells to loci of infection,
however, has not been elucidated. Therefore, we hypothesized that SDR will enhance the innate
immune response by increasing the number of monocytes/macrophages in the TG and increasing
anti-viral cytokine production during a primary HSV-1 infection consequently reducing viral
replication. METHODS: BALB/c mice were exposed to six cycles of SDR prior to being
ocularly infected with HSV-1 McKrae virus. Following infection, leukocytes in the infected
right TG were identified and counted using flow cytometric analysis. Gene expression of anti-
viral cytokines and viral proteins were also examined using real-time PCR. RESULTS: SDR
increased the percentage of monocytes/macrophages in the TG during a primary HSV-1
infection. This was accompanied by an increase in gene expression for IFN-α and TNF-α.
Examination of viral genes showed increased expression of ICP0 in SDR-treated mice and a
concomitant decrease expression for gB and LAT. CONCLUSIONS: SDR enhanced the innate
immune response to the virus as indicated by an increase in inflammatory cells and cytokines.
Although SDR did not prevent neurons from being infected, SDR did impede viral replication as
revealed by decreased expression of gB and LAT, despite higher levels of ICP0. Because early
termination of viral replication can influence the development of latency, it is possible that stress
prior to a primary infection impacts the development of latency. Supported by NIH/NIDCR
T32DE014320-04 and RO1MH046801-13.




Twenty-second Annual Student Research Program Scientific Session:                                 37
February 15, 2006
P15
In-vitro Model for Characterization of NSAID Accumulation by Oral Epithelium
R. Fitzgerald, J.D. Walters

Objective: Nonsteroidal antiinflammatory drugs (NSAIDs) can effectively inhibit pain and
periodontal bone loss when administered in oral topical form. The mechanisms by which
NSAIDs permeate oral epithelium have not previously been characterized. We hypothesize that
oral epithelial cells possess active transporters that accumulate NSAIDs inside the cells. The
objective of this study was to develop an in vitro model for studying uptake of NSAIDs by oral
epithelium;Methods: The oral squamous cell carcinoma line SCC-25 (ATCC CRL-1628) was
seeded into 24 well plates and grown to confluent monolayers. Naproxen entry into epithelial
cells was monitored by measuring cell-associated naproxen fluorescence with a
spectrofluorimeter. Lineweaver-Burk analysis was used to determine the Km of
transport;Results: Naproxen uptake by SCC-25 cells was saturable and its kinetics obeyed the
Michaelis-Menten equation. The cells transported naproxen with an observed Km of 128µg/ml.
Transport activity was influenced by pH, resulting in a 430% increase in transport efficiency at
pH 6.3 and a 45% reduction in transport efficiency at pH 8.3 relative to transport at pH 7.3.
Addition of glycerol (2-10%) to the assay buffer significantly enhanced naproxen entry into
epithelial cells by up to 38% (P < 0.001, ANOVA), while addition of ethanol (2-6%)
significantly inhibited naproxen entry by nearly 50% (P < 0.001);Conclusions: Oral epithelial
cells possess a system for actively transporting naproxen. Transport is enhanced by reducing the
pH to 6.3 and incorporating glycerol into the assay system. Transport is impaired at alkaline pH
and in the presence of ethanol. This model could be useful for optimizing the conditions for oral
topical NSAID application for relief of pain or treatment of periodontitis.
Supported by NICDR grant DE12601.




Twenty-second Annual Student Research Program Scientific Session:                               38
February 15, 2006
P16




Twenty-second Annual Student Research Program Scientific Session:   39
February 15, 2006
P17
Transport of Naproxen by Human Gingival Fibroblasts and PMNs
T. Gbemi, J.D. Walters

Objectives: Topical NSAIDs are effective in treating pain and slowing the progression of
periodontitis. Comparatively little is known about absorption and distribution of these
compounds following oral topical delivery. We hypothesize that PG-producing target cells
possess transporters that accumulate topically-administered NSAIDs that diffuse into the
gingival connective tissue, thereby enhancing their effectiveness. This study characterized
transport of naproxen by gingival fibroblasts (GFs) and polymorphonuclear leukocytes (PMNs)
in vitro; Methods: Human GFs were cultured to confluent monolayers and human PMNs were
isolated from blood by Ficol/Hypaque centrifugation and dextran sedimentation. Naproxen
transport by GF monolayers and PMN suspensions was monitored by measuring the increase in
cell-associated naproxen fluorescence. Lineweaver-Burk analysis was used to determine the Km
and Vmax of transport;Results: Naproxen transport by GF and PMN was saturable and exhibited
Michaelis-Menten kinetics. Resting GF transported naproxen with a Km of 127 ± 9.4 µg/ml and
a Vmax of 1.42 ± 0.14 ng/min/µg protein, while resting PMNs transported naproxen with a Km
of 126 ± 5.8 µg/ml and a Vmax of 21.1 ± 3.2 ng/min/106 cells. GF naproxen transport was
inhibited by 2-deoxyglucose, which depletes cellular ATP. The kinetics of GF naproxen
transport were more favorable at neutral and acidic pH than under alkaline conditions. GF
naproxen transport was competitively inhibited by probenecid, phenol red and penicillin (Ki =
0.41, 0.45 and 2.4 mM, respectively), which are all substrates for organic anion transporters;
Conclusions: GFs and PMNs possess transporters that mediate intracellular accumulation of
naproxen with similar affinity. The GF transporter requires ATP and is most efficient at neutral
to acidic pH. Naproxen transport is apparently mediated by an organic anion transporter. By
enhancing NSAID levels inside PG-producing cells, these transporters could potentially enhance
the effectiveness of topical NSAID therapy.
Supported by NIDCR grants DE12601 and DE14320.




Twenty-second Annual Student Research Program Scientific Session:                             40
February 15, 2006
P18
Representation of Bitter Tasting Chemicals in the Rat NST
L. Geran, S. Travers

A wide variety of chemical compounds are described as “bitter” by humans and avoided by
animals. Molecular data suggest that these compounds bind to members of the T2R family of G-
protein coupled receptors, and furthermore, that all T2Rs are co-expressed in the same group of
taste cells such that any activation would lead to a unitary sensation of “bitterness”. In contrast,
physiological results indicate that these bitter-responsive taste cells are highly selective for only
1 or 2 stimuli, suggestive of distinct taste qualities. To help resolve this conflict, responses from
neurons in the next region of the gustatory system, the nucleus of the solitary tract (NST), were
elicited by 4 bitter compounds found to be equally and highly effective in behavioral tests. Bitter
chemicals varied in neural effectiveness and unlike stimuli of other taste qualities (e.g. “sweet”
or “sour”), largely failed to correlate significantly with one another across neurons. The most
commonly used bitter stimulus, quinine, was particularly ineffective and could explain the
scarcity of bitter-responsive NST units in the literature. In addition, multidimensional scaling and
receptive field tests suggested that bitter stimuli can be separated into 2 groups based on
chemical structure. Nonionic bitter stimuli appear to be limited to the posterior oral cavity, while
ionic bitters activate both anterior and posterior regions and overlap somewhat with salt and acid
responses. These results support the physiological data from the periphery in that bitter-
responsive neurons formed a heterogeneous group, and also suggest that discrimination between
different bitter stimuli could be possible. Supported by NIH DC00716 and CTOC.




Twenty-second Annual Student Research Program Scientific Session:                                 41
February 15, 2006
P19
Oral Cancer Reporting Practices of Relevant Healthcare Providers in Ohio
Dr. Alvin Wee, Kelly Gerhardstein, Meliha Rahmani

Oral cancer is the sixth most common cancer in the United States and the five year survival rate
for oral cancer is 59%. The reporting of all cancer by health care professionals is necessary for
the development of early detection and prevention initiatives. The purpose of this study is to
determine the oral cancer reporting practices of relevant health care professionals in Ohio to the
Ohio Cancer Incidence Surveillance System (OCISS). Relevant health care professionals
include oral pathologists, otolaryngologists, oral surgeons and general pathologists. A two page
survey was mailed to the health care professionals mentioned above. The survey contained
questions pertaining to demographics, oral cancer reporting, clinical practices and biopsy
practices. The survey response rate was 23.7%. Of the health care professionals that responded,
89% diagnose or provide treatment to patients with head and neck cancer. Of the 89% of health
care professionals that diagnose or provide treatment to patients with head and neck cancer, 22%
responded that they report incidences of head and neck cancer to OCISS. From this survey, it is
evident that head and neck cancer is not accurately being reported which misrepresents the
burden of the disease.




Twenty-second Annual Student Research Program Scientific Session:                               42
February 15, 2006
P20
Molecular Analysis of the Biofilm in Caries of the Primary Dentition
E. Gross, J. Martin, K. Asnani, P. Kumar, E.J. Leys, and A.L. Griffen

Dental caries is the most common chronic disease of childhood, and is the biggest unmet health
care need among America’s children. To date, effective biological interventions to prevent caries
have not been developed. Dental plaque contains several hundred different organisms, many of
which are poorly studied. In addition, comparatively little attention has been paid to identifying
health-associated and potentially beneficial bacterial species that may reside in the oral cavity.
Cloning and sequencing bacterial 16S ribosomal genes isolated from plaque samples were used
to identify bacterial species present in childhood caries. This open-ended approach allows the
detection and identification of all bacterial species present, including novel, uncultivated or
unexpected species. Plaque samples were collected from fifteen subjects, age up to 8 years with
severe caries of the primary dentition, and fifteen age-matched healthy controls. A plaque sample
was taken from each of four sites in each caries subject: intact enamel, whitespot lesion,
cavitated lesion, and a lesion that had progressed to dentin. Veillonella atypica and the genera
Bifidobacterium and Lactobacillus showed a significant increase as lesions progressed to dentin.
Several genera decreased in prevalence as lesions progressed to dentin, indicating an association
with health, including Capnocytophaga, Corynebacterium, Eubacterium, Gemella, and Kingella.
Among Streptococci, S. mutans showed a significant increase as lesions progressed, while S.
sanguinis, S. mitis bv2, S. intermedius, and S. cristatus decreased. The significance of this study
is that identification of additional caries pathogens would provide alternative targets for
biological intervention, and identification of beneficial health-associated species could provide
the basis for therapeutic interventions to establish caries-resistant microbial communities.




Twenty-second Annual Student Research Program Scientific Session:                               43
February 15, 2006
P21
Epidemiology of Traumatic Dental Injuries to the Permanent Dentition.
David B. Gustafson, Jason Sperati, DDS, and Dennis J. McTigue DDS, MS

This study analyzed the epidemiology of traumatic dental injuries in the permanent dentition of
patients treated at the Emergency Department (ED) of a large, academic children’s Hospital. A
total of 413 records from patients (957 teeth) were included in the study between August 2003
and January 2006. The patients ranged in age from 5 to 57 years old. Seventy-two percent of
patients were between the ages of 7 and 13 years old, and 65% were male. Most children (73%)
sought treatment within 3 hours of onset of the dental trauma. The most commonly involved
teeth were the permanent maxillary central incisors accounting for 65% of all teeth involved by
dental trauma. Injuries to hard dental structures included tooth fractures (39%). Of those teeth
fractured, the majority (60%) were an uncomplicated fracture including both enamel and dentin.
Periodontal injuries included concussions (28%), subluxations (25%), lateral luxations (16%),
avulsions (11%), and intrusions (3%). The aforementioned data will ultimately be used to
follow-up in outcomes assessments of the treatment provided.




Twenty-second Annual Student Research Program Scientific Session:                              44
February 15, 2006
P22
Regulation of NF-κB Activation by Androstenediol During Wound Healing
Cynthia C. Head, Michael J. Farrow, Amy Hufnagle, John F. Sheridan, David A. Padgett

OBJECTIVES: Pro-inflammatory cytokines that are regulated by NF-κB play an important role
in coordinating the activities of many cells during wound healing. Previous studies have shown
that stress delays healing and alters cytokine production, in part, due to increased levels of serum
glucocorticoids. We have previously shown that treatment of restraint-(RST) stressed animals
with androstenediol (AED) ameliorated the suppressive function of glucocorticoids, while
restoring the expression of pro-inflammatory cytokine genes and wound healing to levels
comparable to those of the unstressed (FWD) controls. Our studies have further suggested that
the inhibitory effects of stress are mediated through an NF-κB-dependent mechanism. These
observations lead to our current hypothesis that the activation of NF-κB will be altered by RST
and restored to control levels with AED treatment. METHODS: To test this hypothesis, male
CD1 outbred mice were subjected to 15-hour cycles of RST beginning 3 days before wounding
and continuing for 5 days post wounding. Control animals were food and water deprived (FWD)
during the same time period. Animals were wounded with a 3.5 mm biopsy punch. Samples were
collected at 12 and 24 hours and 3 and 5 days post wounding, using a 6.0 mm punch to collect
the wound and surrounding tissues. A Nuclear Extract Kit was then used to collect nuclear and
cytoplasmic proteins from the tissue samples. The amount of total protein was analyzed using a
Bradford assay. A TransAM assay was then utilized to detect and quantify activation of the
transcription factor NF-κB. RESULTS: There was a biphasic response with regard to the effect
of RST on NF-κB activation during wound healing. During the first 24 hours after injury, nuclear
localization of p65 dropped by 15% in control animals; wounds from RST animals showed no
such decline. In addition, at 5 days post wounding when nuclear p65 had returned to baseline
levels in the control, activation of NF-κB appeared to be impaired in the RST animals where the
quantity of nuclear p65 was 26% lower. Treatment with AED prevented the effects of RST.
More specifically, activation of NF-κB in RST animals treated with AED paralleled that seen in
the control. CONCLUSIONS: The results indicate that stress alters the kinetics of NF-κB
activation in the wounds of mice. Treatment with AED ameliorated the affects of stress.
However, the kinetics of NF-κB activation did not fully correlate with our previous observations
showing an initial RST-mediated suppression of pro-inflammatory gene expression that we
hypothesized was dependent upon NF-κB. Therefore, we must further pursue the transcriptional
mechanism behind RST’s suppression of early gene expression during wound healing.




Twenty-second Annual Student Research Program Scientific Session:                                45
February 15, 2006
P23




Twenty-second Annual Student Research Program Scientific Session:   46
February 15, 2006
P24
Mechanical Properties of Three Palladium-Silver Casting Alloys for Metal-Ceramic
Restorations
D. Li1, S.B. Alapati1, W.A. Brantley1, W.M. Johnston1, T. Dasgupta2, and P.J. McCabe2, 1
Ohio State University College of Dentistry, Columbus, USA, 2 Ivoclar Vivadent, Amherst,
NY, USA

With the cost of palladium now less than for gold, there is increased interest in palladium-silver
alloys. Objective: Obtain mechanical properties for three Pd–Ag alloys (Ivoclar Vivadent):
(a) IS 64, 59.9Pd–26.0Ag–7.0Sn–2.8Au–1.8Ga–1.5In; (b) d.SIGN 59, 59.2Pd–27.9Ag–8.2Sn–
2.7In–1.3Zn; (c) Aries, 63.7Pd–26.0Ag–7.0Sn–1.8Ga–1.5In (wt%). Methods: Specimens
meeting dimensional requirements in ADA Specification No. 5 were prepared by torch melting
and casting. Four specimens for each alloy were prepared for the as-cast condition and for the
simulated porcelain-firing heat-treated condition, and loaded in tension at a crosshead speed of
2 mm/min. Values of 0.2% yield strength (YS), ultimate tensile strength (UTS) and percentage
elongation were obtained, and fracture surfaces were observed with an SEM. Statistical
comparisons were made using ANOVA and the REGW multiple range test. Results: Mean
values of YS, UTS and percentage elongation, respectively for the heat-treated condition were:
IS 64 (441 MPa, 781 MPa and 26%); d.SIGN 59 (430 MPa, 773 MPa and 18%); Aries (388
MPa, 690 MPa and 46%). Compared to the as-cast condition, YS for d.SIGN 59 significantly
decreased after heat treatment, while percentage elongation for Aries significantly increased.
Significant changes occurred in UTS for the alloys after heat treatment. UTS was significantly
lower for Aries than for IS 64 and d.SIGN 59. All alloys exceeded the minimum YS requirement
in ADA Specification No. 38, and exhibited dimpled rupture associated with ductile fracture.
The same YS to UTS ratio of 0.56 for all alloys indicated the same work-hardening mechanisms.
Conclusions: Each Pd–Ag alloy had acceptable properties for clinical use, with comparable or
higher percentage elongation, and lower YS and UTS, than previously investigated high-
palladium alloys. Casting defects account for the variation in mechanical properties among
specimens of the same alloy. Supported by NIDCR Grant DE10147.




Twenty-second Annual Student Research Program Scientific Session:                               47
February 15, 2006
P25
Assessment of Readability for 25 Pediatric Dentistry Patient Education Materials
H. Lin, H. Amini, and J. Hayes

Objective: To calculate the reading grade level and assess the readability of 25 patient education
articles published on the AAPD website.

Methods: The readability for the 25 articles was assessed using Flesh-Kincaid and Gunning Fog
Index. Mean reading level for Flesch-Kincaid and Gunning Fog Index was calculated and
compared to the recommended upper limit of 7th grade. FK Reading Ease was also calculated
and compared to the target score of 70% and above. Three longer articles were assessed using
Fry Formula.

Results: The reading level of the 25 AAPD articles was significantly more difficult than the
recommended 5th to 7th grade level. The articles scored a mean Flesh-Kincaid grade of 9.12 and
Gunning Fox Index grade of 11.96. The mean FK Reading Ease of 53% was significantly more
difficult than the recommended level of 70%. No single article met the recommended reading
level across all three measures. One article met the recommended level for two of three
measures and three articles met the criteria for Flesch-Kincaid only.

 Table     Flesch-      Gunning       FK Reading
 1         Kincaid     Fog Index         Ease
 Mean       9.12         11.96           53%
 SD          1.8           2.1           12.2
 T           5.8          11.8           -6.96
 P         <0.001       <0.001          <0.001
 Min         6.1           7.4         37.10%
 Max         12           15.9         73.20%

Conclusion: Health information materials should be comprehensible when read by the average
patient. Other determinants such as content, writing style, and graphic elements may also
contribute to the readability of a document. Readability formulas may be a useful guide to help
improve the reading ease of health information materials.




Twenty-second Annual Student Research Program Scientific Session:                               48
February 15, 2006
P26
Blunted Th2 Immunological Memory Profile is Induced by Social Stress Prior to a Primary
Influenza Viral Infection in Male C57 Mice.
JW Mays1, MT Bailey1, DA Padgett1,2,3, JF Sheridan1,2,3,1College of Dentistry, Section of
Oral Biology, 2College of Medicine, Dept. of Molecular Virology, Immunology and
Med.Gen.; 3Institute for Behavioral Medicine Research, The Ohio State University, 305 W.
Twelfth Ave., Columbus, Ohio 43210

Immunoregulation by social disruption stress (SDR) has been demonstrated repeatedly.
However, the impact of social stress on the generation and maintenance of immunological
memory is not well characterized. Previous studies in our laboratory have demonstrated that
mice subjected to SDR prior to a primary influenza infection exhibited reduced morbidity and
mortality during an influenza re-challenge, suggesting that the SDR may have a protective effect.
Subsequent delayed-type hypersensitivity (DTH) challenge with influenza antigen in the hind
footpad after the primary challenge revealed a consistently enhanced DTH response in mice
previously exposed to SDR (SDR-MEM group), suggesting either a prolonged hyper-
inflammatory phenotype or a permanent shift in the immunological phenotype. This study was
designed to profile the influence of SDR prior to a primary influenza infection on the subsequent
anti-viral immunological memory.

The SDR-MEM group underwent 2 hrs of SDR per night for 6 consecutive nights. Each cycle
entailed the introduction of an aggressive mouse that attacked and defeated all C57BL/6 resident
male mice. The non-stress MEM group was isolated from the stressor. Following night 6 of
SDR, all mice were infected intra-nasally with 1 HAU of influenza A/PR8 virus, and then
allowed to recover from the infection. Three months later, mice were re-infected with 16 HAUs
of A/PR8 virus, and immune responses were assessed at days 0, 1, 3 and 5 post-challenge.

An influenza-specific IgG ELISA was used to compare IgG antibody titers in serum samples
from the memory phase and re-challenge. Data across three experiments confirmed a lower
geometric mean IgG antibody titer in the SDR-MEM group during the resting memory phase
(two-sample t-test, p<0.007). This difference was abrogated during re-challenge.

 Lung samples were flash frozen and used for real-time PCR analysis. Expression of influenza
M1 RNA, used to measure viral infection in the lung, was 9.5 fold lower in the SDR-MEM
group at day 1 post-challenge and returned to baseline by day 3 post-challenge, suggesting that
the SDR-MEM mice experienced a less severe viral infection. IL-10 is a major Th2 cytokine
and an inhibitor of Th1 responses. We found 4.2 fold higher expression of IL-10 at day 1 post-
rechallenge in MEM vs. SDR-MEM mice. This data along with the reduced IgG titers in the
resting memory phase suggested that long after exposure to social stress, the SDR-MEM animals
maintained a differential Th2 response. We also observed less viral replication in the SDR-
MEM groups along with an enhanced DTH response. Together these data suggest a shift toward
Th1 memory responses. Further research is needed to confirm this mechanism, however a shift
from Th2 to Th1-type antiviral responses would explain the differences seen in the response of
SDR animals exposed to antigenic challenges.

Supported by NIH grants RO1 MH46801-13 and T32 DE014320-04.


Twenty-second Annual Student Research Program Scientific Session:                              49
February 15, 2006
P27
Neutrophil Formylpeptide Receptor SNP 348T>C in Subjects with Aggressive Periodontitis
P.Maney, J.D. Walters

Objectives: Neutrophil formylpeptide receptors (FPR) play an important role in bacterial
recognition and chemotaxis. We previously reported preliminary findings on the association of
the synonymous FPR single nucleotide polymorphism 348T>C with aggressive periodontitis
(AP) in African Americans. We have extended these findings to a larger population of AP
subjects and controls. Additionally, we conducted preliminary studies of chemotaxis by
neutrophils from subjects in AP and control groups to determine whether the 348T variant is
associated with an impaired chemotactic response to formylpeptides;
 Methods: African-American AP subjects (n=16) and healthy controls (n=13) were recruited
under an IRB-approved protocol. Peripheral blood was drawn and genomic DNA isolated. PCR
amplification and sequencing was done to detect polymorphism 348T>C. Neutrophils from AP
subjects and controls were isolated by ficoll centrifugation, dextran sedimentation and RBC
lysis. Chemotaxis was assayed for 90 min at 37° C with a NeuroProbe 48-well modified Boyden
chamber, using 10nM N-formyl-Met-Leu-Phe as the chemoattractant;
Results: The frequency of 348T>C was significantly different in AP and control subjects, with
348T over-represented in the AP group (P=0.001). The magnitude of the chemotactic response of
three 348T/C AP subjects was 55.9% of that observed in four 348C/C controls (P < 0.05).
Random migration was similar in AP and control subjects (P = 0.2). Neutrophils from one AP
subject genotyped as 348C/C exhibited chemotactic response and random migration similar to
controls;
Conclusions: The findings suggest that individuals with the 348T variant have an increased risk
of developing AP and have neutrophils that exhibit impaired chemotaxis to formylpeptides
relative to those with 348C. Although the 348T>C polymorphism is synonymous, it may be
linked to other polymorphisms in the FPR promoter region. This type of linkage is observed in
the human â2 adrenergic receptor gene and is associated with reduced receptor expression.
Supported by R01DE12601.




Twenty-second Annual Student Research Program Scientific Session:                               50
February 15, 2006
P28
Mandibular Bone Mass and Geometry of C57BL/6J (B6) and B6.C3H-4T (4T) Mice.
Meta IF1, Huja SS1,2, Turner CH3. 1Section of Oral Biology and 2Orthodontics, College of
Dentistry, The Ohio State University, 3188 Postle Hall, 305 W. 12th Avenue, Columbus,
OH 43210, USA. 3Department of Orthopaedic Surgery, Indiana University School of
Medicine, Indianapolis, IN 46202, USA.

B6.C3H-4T (4T) mice show a ~ 10% greater femoral mass than C57BL/6J (B6). We
hypothesize that 4T have greater mandibular bone mass than B6 mice. Hemimandibles were
dissected from 8-week-old female (f) and male (m) 4T (nf=13; nm=13), and B6 (nf=5; nm=8)
mice and embedded in plastic. Lateral view Faxitron radiographs of the hemimandibles were
divided at the level of 3rd molar level into an anterior and posterior region and measured using a
computer imaging program. Then, the entire hemimandible was sectioned transversely. Four
consecutive transverse sections (80 μm) beginning from the distal of the third molar were
selected for analysis of cross sectional area (CSA) and measured with a Merz grid.
Hemimandibles where the coronoid process was not intact were excluded from analyses. Mann-
Whitney test was used to compare area parameters of the 4T and B6 hemimandibles from the
same side.

                MALE (Means ± SE, mm2)                      FEMALE (Means ± SE, mm2)
                 Right            Left                        Right                Left
              4T       B6     4T        B6                4T         B6       4T          B6
             1.53    1.48    1.54      1.51              1.67       1.43     1.69        1.54
   CSA            a       a       a
           (.025) (.026) (.035) (.034)a                (.017) c
                                                                  (.038) c
                                                                           (.036) a
                                                                                       (.101)a
            n=10     n=7     n=8       n=6               n=8        n=5     n=10         n=3
            14.84 14.86     15.01     15.28             14.61      14.77    15.21       14.31
   Ant.
           (.120)a (.192)a (.247)a (.300)a             (.282)a    (.307)a  (.194)a     (.539)a
   Area
             n=8     n=7     n=7       n=7               n=9        n=5     n=11         n=3
            22.90 21.86     23.21     21.75             21.17      18.12    20.70       18.55
   Post.
           (.462)a (.344)a (.316)b (.244)b             (.343)c    (.459)c  (.313)b     (.151)b
   Area
             n=8     n=7     n=7       n=7               n=9        n=5     n=11         n=3
a        b      c
  p>.05; p<.05; p<.01

The parameters that were significantly different were ~ 10-17% greater in the female 4T and the
posterior area was ~ 5-6% greater in the male 4T. We conclude that 4T mice have a trend
towards greater mandibular bone mass than B6 mice, the difference being larger in the female.
This suggests that the mechanosensitivity of the 4T mice extends to the osseous tissues in the
craniofacial region.




Twenty-second Annual Student Research Program Scientific Session:                                51
February 15, 2006
P29
Reactive Species Activation of NFκB in HNSCC
J. Bradburn, A.P. McCormick, J.C. Zwick, S.R. Mallery

        Epidemiological studies correlate head/neck squamous cell carcinoma (HNSCC)
occurrence with chronic inflammation, defined as the prolonged presence of inflammatory
cytokines and/or reactive species (RS). RS such as reactive oxygen (ROS) and reactive nitrogen
(RNS) share the common property of being highly reactive due to the presence of an unpaired
electron. RS promote tumorigenesis by mechanisms including sustained cell proliferation,
increased production of growth factors and induction of angiogenesis. Additional studies have
shown the relevance of the transcription factor nuclear factor (NF) κB activation on HNSCC
development and progression. In a resting cell NFκB is bound to inhibitory proteins (IκB) in the
cytoplasm. Upon stimulation IκB is phosphorylated by IKK kinases and targeted for
ubiquitination and proteolysis which allows NFκB to translocate to the nucleus. Once in the
nucleus NFκB binds a consensus DNA sequence and recruits proteins required for gene
transcription. Reactive species (RS) may play either a stimulatory role in the cytoplasm by
increasing oxidant levels and activating IKK kinases, or conversely, an inhibitory role by
oxidizing the nucleus and preventing NFκB subunits from binding DNA.
        This study investigates the effect of RS using a model system that assesses activation of
NFκB and downstream production of key growth factors IL 8 and VEGF, which are both at least
partly regulated by NFκB. A reporter gene construct was used to determine NFκB activation. IL
8 and VEGF protein was quantified by ELISA. In total five HNSCC lines were obtained from
the ATCC. RS stress was stimulated by the addition of either TNF (100U/ml), H 2O2 (0.2mM for
transfection studies, 0.1mM for ELISA studies), 2,2′-(hydroxynitrosohydrazino)bis-ethanamine
(NOC 18, 25µM) or 3-morpholinosydnonimine (SIN 1, 100µM). TNF is an inflammatory
cytokine known to activate NFκB and generate RS as second messengers. H 2O2 is a stable
source of reactive oxygen. NOC 18 releases reactive nitrogen. SIN 1 releases equimolar
amounts of reactive oxygen and nitrogen. Response was determined relative to control cells in
base media.
        Results from the following preliminary studies are as follows. Transfected SCC 2095
cells show activation of NFκB in response to RS treatment. Although it is an artificial system,
this reporter does suggest that RS induced activation of NFκB since the gene was transcribed,
which can only happen in the nucleus. ELISA studies were used to further develop this concept
by measuring the levels of endogenous proteins secreted into the media over 96 hours. Both IL 8
and VEGF proteins contain κB binding elements in the promoter region of their respective genes.
Media was sampled every 24 hours just prior to the addition of fresh treatment. Addition of TNF
significantly increased IL 8 levels in the media at 72 hours (n=6, p<0.01). In response to H2O2
treatment SCC 4 cells showed a stronger response in IL 8 media levels which were significantly
increased at 48, 72 and 96 hours (n=6, p<0.001 in all cases.) Both treatments peaked at 72 hours
and then decreased. No response was seen following treatment with either NOC 18 or SIN 1.
This could be an artifact of having normalized the data to total protein. Protein levels were
significantly increased in cultures treated with NOC 18 or SIN 1 (n=6, p<0.01 for both.) This
may have eclipsed any real difference between treated and non-treated cultures. Ongoing work
includes repeating transfection of SCC 2095 cells, continuing to collect samples for ELISAs
which will be normalized to cell number not protein as well as developing methods to detect and
quantify nuclear localization of NFκB subunits.


Twenty-second Annual Student Research Program Scientific Session:                             52
February 15, 2006
P30




Twenty-second Annual Student Research Program Scientific Session:   53
February 15, 2006
P31
Periodonal and Peri-Implant Health: Associations in Periodontal Maintenance Patients
P. Nolan, B. Leblebicioglu, F. Beck, A. Mariotti, and D.N. Tatakis

Purpose: There is evidence suggesting that peri-implant health may be affected by a history of
periodontitis. The aim of this study was to determine possible associations between changes
observed in periodontal and peri-implant parameters in periodontal maintenance patients.
Methods: A retrospective study design was used to screen periodontal records of patients who
received non-surgical and surgical periodontal therapy followed by implant placement within the
last 5 years. The inclusion criteria included compliance to maintenance appointments (MAs) for
at least 2 years. Twenty-six patient records (61 implants) with complete periodontal charts from
at least 2 MAs were included. A 2 mm difference in probing depth (PD) between any given 2
MAs was chosen to compare peri-implant and adjacent periodontal tissues. Logistic regression
analysis was used to model the relationship between PD changes seen around implant and
adjacent tooth (P<0.05). The data were controlled for gender and smoking status. Results:
Included subjects had an average of 2.9+/-1.3 MA visits and 3.4+/-1.1 years of implant function.
The relation between observed PD changes around implant and adjacent tooth at any given 2
MAs was statistically significant (P<0.05) for disto-buccal (OR=4.75, tooth vs. implant), mesio-
buccal (OR=5.51), palatal (OR=10.3) and disto-palatal (OR=5.67) surfaces. Only 6 % of the
peri-implant sites showed no BOP when plaque was <30% compared to 38% of the periodontal
sites. The increase in total number of implants per patient had a significant (P<0.05) effect on PD
changes observed on mid-buccal (OR=0.47) and mesio-palatal (OR=0.38) peri-implant surfaces.
Conclusions: The results indicate that peri-implant health, as assessed by PD changes, is
associated with periodontal health changes, suggesting that PD should remain as an important
parameter to evaluate both periodontal and peri-implant status in periodontal maintenance
patients. (Supported by CTOC Program, NIDCR Grant T32 DE14320 and the Section of
Periodontology)




Twenty-second Annual Student Research Program Scientific Session:                                54
February 15, 2006
P32
Potential Prognostic Factors for Dental Implant Failures
B. Paulus, B. Leblebicioglu, F. Beck, D.N. Tatakis, and A. Mariotti

Purpose: Currently acceptable criteria used to evaluate implant treatment outcome have
limitations in defining prognosis and long-term success. The aim of this study was to determine
whether different variables including surgeon's experience and characteristics of implant site
should be considered as factors in dental implant success, in addition to known risk factors.
Methods: A retrospective study design was used to screen implant cases treated at the Graduate
Periodontics Clinics within the last 5 years. The inclusion criteria included complete
maintenance records for at least one year following implant loading. 100 cases were selected
from total of 792 screened records. These included 269 dental implants placed by 19 second or
third year periodontal residents. Logistic regression analysis was used to determine statistically
significant associations between implant failure (IF) and age, gender, need for graft procedure,
resident's year, previous history of periodontal treatment, reason for tooth extraction and
complications seen prior to loading, in addition to systemic health factors.
Results: Average time in function was 3.1+/-1.6 years with 21 implants failed: 8 implants failed
prior to, 5 failed at the time of and 8 failed after loading. The failure rate for implants placed by
second and third year residents was 10.6% (16 out of 151 implants) and 4.2% (5 out of 118
implants), respectively (P>0.05). Most recorded complications included lack of stability, peri-
implantitis alone or in combination with exposed implant/graft material, and loose healing
screws. The relation between IF and gender (females to males OR=0.157, 95%CI=0.035/0.704)
and IF and complications seen prior to loading (prior to others OR=19.1, 95%CI=3.81/95.4) was
statistically significant (P<0.05). Conclusions: The results suggest that future longitudinal
studies on prognostic factors for implant failures should consider additional factors, such as
complications prior to loading. (This study was supported by OSU, College of Dentistry, Student
Research Program)




Twenty-second Annual Student Research Program Scientific Session:                                  55
February 15, 2006
P33
Dentin Adhesion: Are Fewer Steps Better?
E. Prochaska, M. Slabodnick, C. Cripe, and R. Seghi

Objective: Numerous restorative procedures rely on the application of dental adhesives. These
systems have continued to evolve resulting in product changes at an accelerated rate. These
changes have resulted in several products from each manufacturer. The purpose of this
investigation was to evaluate the resulting Microtensile Strength (MTS) of the various systems
produced by two manufacturers. Methods: Approximately 3-4 mm of composite (Herculite XR,
Kerr) was directly bonded to flattened off extracted human 3rd, molars with one of the six
bonding agents. Summarized below. Six specimens of each adhesives type were fabricated and
stored

ID    Product Name Manufacturer Etch type Solution App
                                          Steps

OF    Optibond F        Kerr            Total-etch 2

O+ Optibond Solo Kerr                   Total-etch 1
   plus

OSE Optibond Solo Kerr                  Self-etch 2
    SE

PB    Clearfil Photo Kurraray           Total-etch 2
      Bond

S3    Clearfil S3       Kurraray        Self-etch 1

SE    Clearfil SE       Kurraray        Self-etch 2

in water for approximately 1 week at 37°C. The interface strength was assessed using
microtensile bond tests. Each specimen was sectioned into bars of approximately 1mm2 cross
section using a slow speed diamond saw. The bars were tested in tension and the failure load (N)
for each specimen recorded. The microtensile strength (MTS) was calculated. Data was
subjected to survival analysis methods. Results: The results of the Wilcoxon test indicated that
the adhesive type significantly influenced (p<0.001) the resulting MTS. The results of a
parametric survival fit using a Weibull distribution suggested that the number of solution
application steps significantly influences the resulting MTS (p=0.003) while the etch type did not
(p=0.2) Conclusion: The data suggests that more thorough resin penetration from the multiple
solution applications onto the dentin may be more important to the bond strength than the
method of etching the dentin. Supported by NIDCR R21 DE14719 and OSU Dental summer
research program.




Twenty-second Annual Student Research Program Scientific Session:                               56
February 15, 2006
P34
Histomorphometric Analysis of Bone Supporting Screws at 6 Weeks Post-Insertion
J. Rao1, F. Beck2, A.S. Litsky2, and S. Huja2, 1Ohio State University, School of Dentistry,
Columbus, USA, 2Ohio State University, Columbus, USA

Miniscrews are increasingly being used to enhance orthodontic anchorage. Objectives: The
specific aim of this study was to evaluate the adaptive changes occurring in bone adjacent to a
screw interface at 6 weeks post implantation. Methods: Self-drilling (Synthes, USA) screws
(102) were placed in 7 dogs at predetermined sites in both jaws. Calcein labels were
administered at day 33 and day 40. Animals were sacrificed at day 42. Jaws were dissected and
undecalcified sections, each containing the screw and its adjacent bone, were obtained. Thirty-
seven sections were examined by histomorphometric methods. Mineral apposition rate (MAR),
bone formation rate (BFR) and bone contact (BC) were quantified in the bone supporting the
screw. Modeling response in both jaws was also quantified. Results: The BFR in the bone
directly adjacent (0-1mm) to the screw was significantly greater (32.7±38.1 vs. 10.2±12.5,%/yr,
p=0.01) than in the bone further away (1-4mm) from the screw. The BFR in the mandible was
significantly (p=0.001) higher than in the maxilla (35.5± 27.2 vs. 11.6±7.8, %/yr). No significant
difference (p>0.05) existed in BC in mandible (94.2±2.9, %) vs. the maxilla (84.7±18.8, %).
Periosteal callus thickness of the maxilla was significantly greater (p=0.032) than the mandible.
Remodeling and modeling dynamics in bone-screw interface were similar to that observed
around endosseous implants. BC for self-drilling screws is typically higher than self-tapping
screws placed with a pilot hole. Conclusions: BFR in the mandible was 3-fold greater than in the
maxilla. There was a decreasing gradient of BFR from bone adjacent to the screw to bone further
away. A vital remodeling interface was seen at 6 weeks post insertion of screws. This suggests
an adaptation response, which is necessary for sustenance of the screws during their clinical
application existed at 6 weeks post-insertion.




Twenty-second Annual Student Research Program Scientific Session:                               57
February 15, 2006
P35
Cyclic Loading Effect on Interface Strength of Composite Onlay-like Restorations
T. Roongruangphol, R. Seghi, and N. Katsube

Objectives: The long-term influence of chewing forces on the interface of direct and indirect
composite restorations is not well understood. The purpose of this study was to evaluate the
influence of cyclic vertical loading on the residual strength of restoration/dentin interface.
Methods: Composite disks (MZ100, 3M ESPE) of 1.5 mm thickness were luted to flattened off
extracted human 3rd molars with a resin luting agent (Nexus 2, Kerr) using manufacturer's
recommended instructions. Six simulated onlay specimens were stored in water @ 37°C (CT)
and the remaining 6 specimens were subject to 200 N max vertical loading for a total of 10
million cycles in water at 37°C (FT). The interface strength was assessed using microtensile
strength tests (MTS). Each specimen was sectioned into bars of approximately 1 sq.mm. cross
section using a slow speed diamond saw. The bars were tested in tension and the failure load (N)
for each specimen recorded. The MTS was calculated.
Results: The MTS specimens were subjected to survival analysis. The results of the Wilcoxon
test indicated that group FT resulted in significantly lower MTS (p=.01) than the CT group. The
resulting characteristic Weibull means were CT = 25.7 Mpa, and FT = 18.9 Mpa. The shape
parameters (m) were CT = 1.4 and FT = 1.8. The location of the MTS specimens (Peripheral,
Middle or Center) did not significantly affect the measured strength of either the FT (p=0.29) or
CT (p= 0.52) groups.
Conclusions: Compressive loading significantly reduced the resulting MTS of the interface in
onlay-like restorations bonded to dentin
Supported by NIDCR R21 DE14719




Twenty-second Annual Student Research Program Scientific Session:                                58
February 15, 2006
P36
Indentation Properties of Young and Adult Canine Condylar Bone
A M Rummel, F M Beck, S S Huja

Objectives: The purpose of the study was to determine if differences existed between the
indentation modulus (IM) and hardness of condylar bone in young and adult dogs. Methods:
Mandibular condyles were obtained from adult (1-2yr. old) and young (~5m old) dogs. From
each dog (n=6, adult; n=4, young) a 3-4mm thick bone section was obtained. The condyles were
sectioned antero-posteriorly resulting in 19 (7 young and 12 adult) bone sections for indentation
testing. Frozen specimen was thawed, mounted on a specimen holder and polished on day of
testing. The condylar bone was divided into two regions (near and far) based upon proximity to
the articular cartilage. In adult dogs, the distinct subchondral plate of bone was also quantified.
A total of 2706 indents (young=902, near=423, far=479; old=1804, near=769, far=818,
plate=217) were made on moist condylar trabecular bone to a depth of 500µm at a loading rate of
10nm/s using a custom-made hydration system. IM and hardness values were analyzed using a
repeated-measures factorial analysis of variance and Tukey-Kramer method. Results: Overall,
the IM of the adult condyles (10.0±3.4GPa, Mean±SE) were significantly (p<0.0001) higher than
in young dogs (5.6±2.6GPa). There was no significant (p=0.14) difference in IM between near
and far region in adult condyles. However, the far region (6.2±2.6GPa) had a significantly
(p=0.0007) higher IM than the near region (5.0±2.4GPa) in young condylar bone. Discussion:
The effect of age on material properties of condylar bone has not been reported. This data
suggests that the trabecular bone within the young condyle has lower indentation properties then
adult condylar bone. This data also provides the baseline information needed to compare healthy
to diseased bone. Conclusion: The relative IM of adult condylar bone is nearly two fold greater
than young condylar bone.




Twenty-second Annual Student Research Program Scientific Session:                               59
February 15, 2006
P37




Twenty-second Annual Student Research Program Scientific Session:   60
February 15, 2006
P38
Fiber Reinforced Composite Pins
R. Scoresby, T. Wiltshire, D. Ayala, W.M. Johnston, and C. Machado

Objectives: This study was performed to determine how composite reinforced composite pins
perform in compressive force tests with and without fatiguing and compare the results to similar
tests done on teeth prepared with conventional metallic pins.
Methods: Forty maxillary premolars were collected and divided into four groups of ten (Fiber
Pin with Composite restoration (FPC), Fiber Pin with Amalgam restoration (FPA), Metal
Pin/Composite (MPC), Metal Pin/Amalgam (MPA). The teeth were then mounted in acrylic
resin and the lingual cusp of each tooth was removed. Metal or fiber pins were placed and the
cusps were restored to their original level with amalgam or composite. Each group was then
divided again and five teeth from each group were tested for compressive strength in an Instron
Universal Testing Machine and the remaining five were fatigued in a chewing machine for one
million cycles at 200 N, followed by one million cycles at 400 N, followed by one million cycles
at 600 N. Those teeth that survived the fatiguing process were tested for compressive strength in
the Instron machine.
Results: Due to non-normal data we used a nonparametric one-way anova test for ranked data.
Rankings were assigned with the lowest rank given to the first tooth to fail in fatiguing and
highest rank given to the last to fail. Fiber pins had a mean score of 13.35 while metal pins had a
mean score of 7.65. Chi-square 4.7195, DF=1, p= .030.
Conclusions: Within the confines of this test, when comparing the type of pin used, fiber
reinforced composite pins were found to be significantly more resistant to fatigue than metal
pins.

Supported by The Ohio State University Student Research Program




Twenty-second Annual Student Research Program Scientific Session:                                61
February 15, 2006
P39
Modulation of the Beta-Catenin Pathway by Biomechanical Signals in TMJ
D. Sjostrom, J. Deschner, S. Agarwal

Mechanical loading is a promising approach to limit inflammation, fibrocartilage degradation,
and pain in temporomandibular joint (TMJ) disorders. The Wnt/beta-catenin signaling network
modulates the differentiation, proliferation, and maturation of cartilage. The role of this pathway
in regulating the beneficial effects of dynamic tensile forces (DTF) on fibrochondrocytes is yet to
be elucidated.
Objectives: In this in vitro study, we hypothesized that beta-catenin signaling mediates the anti-
inflammatory effects of DTF in TMJ fibrochondrocytes (FC).
Methods: FC from rat TMJ discs were isolated, phenotyped, grown on flexible bottom plates,
and subjected to DTF (20%; 0.05Hz; Flexercell) in the presence or absence of interleukin (IL)-
1beta, for various time intervals. Unstretched cells with or without IL-1beta were used as
controls. Real-time and end-point PCR, Western blots, and immunofluorescence were performed
to examine the regulation of the Wnt/beta-catenin signaling pathway and associated molecules.
One-Way ANOVA and the post-hoc multiple comparison Tukey test (p<0.05) were
implemented.
Results: (1) The levels of constitutively expressed Wnt3a were suppressed 52±5% by IL-1beta.
However, DTF abolished IL-1beta-induced Wnt3a downregulation in FCs. (2) IL-1beta
upregulated the mRNA expression (401±4%) and synthesis of N-cadherin, which was
downregulated by DTF to 125±5% compared to controls. Furthermore, DTF suppressed the IL-
1beta-dependent translocation of beta-catenin to the cell periphery, suggesting that DTF
upregulates beta-catenin signaling through inhibition of the IL-1beta-induced N-cadherin
expression. (3) IL-1beta significantly diminished the expression of Fer, a kinase in the beta-
catenin activation pathway. However, BCL9-2 and src were not affected by either IL-1beta or
DTF.
Conclusions: Signals generated by DTF utilize the beta-catenin pathway to abrogate the
proinflammatory effects of IL-1beta on Wnt3a and N-cadherin gene transcription and synthesis.
Thus, the Wnt/beta-catenin pathway is critical for the beneficial effects of mechanical loading on
inflamed TMJs. DE15399, DE13799, DE014320, and DE017269.




Twenty-second Annual Student Research Program Scientific Session:                                62
February 15, 2006
P40
STAT1 and T-bet Play Distinct Roles in Determining the Outcome of Visceral
Leishmaniasis Caused by L. donovani1.
H. M. Snider, L. E. Rosas, J. Barbi, A. A. Satoskar, G. Lugo-Villarino , T. Keiser, T.
Pappenfuss, J.E. Durbin, D. Radzioch , L.H. Glimcher, A.R. Satoskar

T-bet and STAT1 regulate IFN-γ gene transcription in CD4+ T cells, which mediate protection
against Leishmania. Here we show that T-bet and STAT1 are required for the induction of an
efficient Th1 response during L. donovani infection, but they play distinct roles in determining
the disease outcome. Both STAT1-/- and T-bet-/- mice failed to mount a Th1 response after L.
donovani infection, but STAT1-/- mice were highly resistant to L. donovani and developed less
immunopathology, whereas T-bet-/- mice were highly susceptible and eventually developed liver
inflammation. Adoptive cell transfer studies revealed that STAT1 in non-T cells was sufficient
to induce pathology and restore susceptibility. However, STAT1 in T cells was required to
control parasite growth once the infection was established in the liver. These unexpected findings
reveal distinct roles for T-bet and STAT1 in mediating host immunity and liver pathology
against visceral leishmaniasis.




Twenty-second Annual Student Research Program Scientific Session:                              63
February 15, 2006
P41
Delivery of Transforming Growth Factor-Beta 3 (TGF-BETA3) Plasmid in a Collagen Gel
Vehicle Delays Fusion of the Rat Posterior Frontal Suture In Vivo
S. Premaraj, B. Mundy, M. Mooney, A.M. Moursi

Purpose:
To determine the ability of an increase in non-viral, plasmid-encoded Tgf-beta 3 production to
inhibit the fusion of rat posterior frontal sutures in vivo.

Methods:
Fifteen days after birth, rat pups received sub-dermal injections superficial to the posterior
frontal suture. Rats were randomly assigned to one of three groups and injected with: 1) PBS
(Sham Control), 2) collagen gel vehicle with Tgf-beta 3 plasmid, 3) collagen gel vehicle with
carrier plasmid, pCMV6-xl5. Ten days after injection, rats were euthanized by CO2 narcosis and
the posterior frontal sutures were harvested for histological examination. Briefly, tissues were
fixed, decalcified and paraffin-embedded, then sectioned at 6 µm using the coronal suture as a
landmark. The extent of bony bridging at the sutures was measured at progressive distances
anterior to the coronal suture. Percent bridging was calculated as bridging height divided by
suture height x 100. Percent bridging were measured from sections every 6 µm beginning at 600
µm from the coronal suture and extending 900 µm anteriorly. Statistical analysis was performed
using a one-way analysis of variance (ANOVA) comparing percent suture fusion in each group.
Post hoc tests were performed using the Tukey-Kramer multiple comparison test with p< 0.05
considered significant.

Results:
In all animals bridging began on the endocranial side and extended ectocranially. In animals
implanted with collagen gel containing Tgf-beta 3 plasmid, a statistically significant reduction in
mean percent bridging of the posterior frontal suture was seen (p<0.05) as compared to animals
implanted with either PBS or the carrier plasmid.


Conclusions:
The above results indicate that an increase in plasmid-encoded Tgf-beta 3 was effective in
maintaining the patency of rat posterior frontal sutures in vivo. This study supports the important
role of Tgf-beta 3 in cranial suture fusion and its possible clinical applications in the prevention
of re-ossification following surgical treatment of craniosynostosis.




Twenty-second Annual Student Research Program Scientific Session:                                 64
February 15, 2006
P42
Restraint Stress Differentially Affects Oral and Cutaneous Wound Healing
B.Leblebicioglu, L.Thomas, D. Padgett, J.Sheridan

Purpose: Microbiological challenge, host response and behavioral characteristics influence
wound healing. It has been reported that mucosal wound heal faster and have less scar tissue
formation than cutaneous skin wounds. The aim of this study was to develop an animal oral
mucosa wound model to study the effect of restraint stress (RST) on mucosal healing and to
delineate differences in repair of these two types of tissues.

Methods: Oral mucosal and dorsal cutaneous wounds were placed on CD-1 mice to assess
differences with regard to rate of healing and gene expression. Animals were subjected to
restraint stress (RST) starting 3 nights prior to injury and continuing for 3 additional days post
wounding. Wound closure was assessed by taking standardized pictures and measuring gene
expression for selected anti-inflammatory and pro-inflammatory cytokines, growth factors and
matrix metalloproteinases (MMPs) was studied using RT-PCR. In addition, ELISAs were used
to analyze protein expression of specific cytokines at different time points during the early phse
of wound healing. Statistical differences between groups were determined by ANOVA followed
by the Tukey test (P<0.05).

Results: Similar to what has been reported for cutaneous wounds, stress delayed healing of oral
mucosal wounds. Likewise, RST suppressed IL-6 expression in both wounds. However, in
contrast to cutaneous tissues, expression of IL-1 beta, MMP-8 and TIMP-1 were each induced by
RST in the oral wound tissues.

Conclusions: The results of this preliminary study indicate that although RST delays healing of
an oral mucosal wound like it does to cutaneous wounds, stress differentially affects the
expression of those genes expressed during the early inflammatory phase of healing.




Twenty-second Annual Student Research Program Scientific Session:                              65
February 15, 2006
P43
Histomorphometry of Mandibular Condyles in Young Canine Dogs
D.R. Thurman*, S.S. Huja

Objectives: Our long term goal is to understand the changes in bone mass, architecture and
material properties associated with aging. We have demonstrated a significant difference in
material properties of young versus old mandibular condyles through indentation testing. The
purpose of this study was to quantify the bone architecture and mass in the mandibular condyle
of young beagle dogs.
Methods: Mandibular condyles were obtained from 4 young dogs (~ 20 weeks old). A pair of
calcein bone labels were administered at 16 and 2 days prior to sacrifice. Two undecalcified
sections (~ 80 µm) were obtained from both the right and left side of each condyle. Bone under
the articular cartilage was examined using histomorphometric methods at 100X. One section
from the right and left side of each canine condyle was stained with Goldner's Trichome for
evaluating percent osteoid surface and percent bone surface. In nonstained sections we calculated
percent labeled bone and percent porosity.
Results: Osteoid covered 65.1 ± 12.0% (Mean ± SD) of bone surface. Two thirds (66.1 ± 4.4%)
of the bone was labeled and its porosity was 39.8 ± 7.6%.
Discussion: These measurements provide baseline histomorphometric data on developing
mandibular condyles. A high percent of bone tissue in young dogs is covered by osteoid and is
newly formed. This is in agreement with the two fold difference in observed indentation modulus
of previous experiments. We hypothesize that older dog condyles would have substantially less
osteoid and labeled bone but with increased porosity due to an overall higher indentation
modulus of supporting bone.
Conclusion: The trabecular bone in the condylar head is rapidly forming with a large percentage
of the bone surface covered by osteoid.




Twenty-second Annual Student Research Program Scientific Session:                              66
February 15, 2006
P44
The Reliability of the OQLQ in an American Population
J. Whitesides, S. Shanker, A. R. Firestone, and F. M. Beck

Cunningham, Garratt, and Hunt (2000) developed a conditions-specific quality of life measure
for patients with a dentofacial deformity. This instrument, the Orthognathic Quality of Life
Questionnaire (OQLQ), was found to be reliable in Great Britain using the test-retest technique.
Cultural influences may affect the perception of oral impacts on quality of life. To account for
cultural differences, quality of life instruments should be validated cross-culturally.

Objectives: This study was designed to test the reliability of OQLQ with an American
population.

Methods: 50 consecutive patients were selected from the dentofacial clinic at OSU whose
proposed treatment plan included orthognathic surgery to correct the deformity. The OQLQ
containing 22 statements reflecting the impact of facial deformity on the individuals’ quality of
life was administered. The questionnaire was repeated 3 weeks later to assess the test-retest
reliability. Reliability was analyzed using an intra-class coefficient (ICC) with a 95% confidence
interval.

Results: 15 patients completed and returned the first questionnaire. 10 of theses patients
completed a second questionnaire. The questionnaire was divided into four components which
were:
    First component – social aspects of deformity
    Second component – facial aesthetics
    Third component – oral function
    Fourth component – awareness of facial deformity
The first three components had good reliability with ICC’s ranging from 0.68 to 0.75. The last
component showed poor reliability with an ICC of 0.16.

Conclusions: Three of the four components of the OQLQ were found to be reliable in an
American population. Quality of life instruments, like the OQLQ, are likely to be of importance
in the future in order to investigate treatment need and outcomes. A complete understanding of
orthognathic surgery to correct skeletal mal-relationships and its effects on quality of life are
essential to document the benefits derived from treatment.




Twenty-second Annual Student Research Program Scientific Session:                                67
February 15, 2006
P45
Assessment of the Esthetic Acceptability of Orthodontic Appliances
J. Ziuchkovski, W.M. Johnston, D.T. Lindsey, H.W. Fields

To date, no studies have been published in the refereed literature evaluating the esthetic
acceptability of orthodontic appliances. Objectives: Appliance acceptability was evaluated for
adults and their children. Appliance variables including material, brand, wire, and ligature were
assessed for acceptability. Demographic factors were also evaluated. Methods: Orthodontic
appliances were placed on one consenting adult and digital images subsequently captured,
standardized, and incorporated into a computer-based survey. Subjects (n=200) rated each image
as acceptable or unacceptable for themselves and their children. Statistical analyses (Chi-
squared and Fisher’s Exact test for demographic factors, Wilcoxon Matched-Pairs Signed-Ranks
for pair-wise image comparison, and categorical modeling for parent/child comparison) were
performed with Bonferroni corrections (overall <0.05). Results: Acceptability rates for
ceramic and stainless steel (SS) appliances (including self-ligating appliances) ranged from 78.9-
94.5%, and 49.0-59.6%, respectively. When rating for their children, acceptability for the same
ceramic and SS groupings ranged from 83.8-94.5%, and 64.8-67.8%, respectively. Both
acceptability responses for the no-appliances and clear tray material images ranged from 98.5-
100%. No demographic factors were found significant. All pair-wise comparisons revealed
significant differences in acceptability between the following appliance groups: ceramic
appliances, SS appliances, and no-appliances/clear trays. There were no differences detected
between self-ligating brackets, nor between self-ligating and standard-twin SS brackets. There
was a significant difference detected between the conventional and reduced size standard-twin
SS brackets. Acceptability of some ceramic appliances was significantly affected by arch-wire
and ligatures. Significant differences between adult and child acceptability were found for all
SS, self-ligating, and several ceramic appliance combinations. Conclusion: Orthodontic
appliance acceptability varies significantly among ceramic, SS, and unconventional appliance
systems. Adults rate SS, self-ligating, and several ceramic appliances as more acceptable for
their children than for themselves.




Twenty-second Annual Student Research Program Scientific Session:                              68
February 15, 2006

								
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