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5_ Pit and Fissure Sealants Study Workbook

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					Pit and Fissure Sealants




 Study Workbook




           1
Prior to reading this section of the Sealant Packet, read chapter 59 of MOD and answer all
the workbook questions.

                                                                     Due Date ____________


Pit and Fissure Sealants
Introduction

        Pits and fissures occur during tooth development and result in incomplete closure or
fusion of the lobes of the teeth. The incomplete fusion creates narrow pathways into the enamel
that can trap food and microbes and create acid producing fluids. The presence of such acid
producing fluids within the fissures can easily create dental caries, even in patients with good
oral hygiene. (See MOD – page 968 Figs 59.1 and 59.2.)
        Throughout modern history several attempts have been made to fill-in these defects with
various types of materials. In the earlier part of the twentieth century, copper cement was
drizzled into the defective areas. Because dental cements are highly soluble in saliva, this attempt,
though well intended, failed. Later, it became commonplace to perform a procedure called a
preventive odontonomy. This procedure involved the removal of the pits and fissures with a
dental bur, and the placement of a conservative amalgam restoration. This technique was hardly
a preventive procedure since it involved the removal of tooth structure. In addition, when the
amalgam became defective or worn, it was replaced with an even larger restoration.
        In the 1950‟s Dr. Michael Buonocore developed a technique for etching teeth with
phosphoric acid. The acid created a rough surface by forming micropores between the enamel
rods. A thin layer of low viscosity polymer (plastic) was added to the occlusal surface of the
tooth and thus was borne the first modern attempt at pit and fissure sealants. Dr. Bowen started
the development of dental composite restorations in the 1960s and sealant material developed
along with composite restorative materials. Since the early days of sealants placement, both
products and techniques have been improved. (See MDA page 968 Fig. 59.3.)

Legal Issues

        In September of 2004 the California legislature approved major changes in the Scope of
Practice for dental assistants. Included in the document was the approval the placement of pit and
fissure sealants by the RDA. Placement of sealants requires that the RDA successfully complete
Board approved course of instruction. After completion of the course, sealants may be placed by
the RDA in a clinic, office or public health setting at the discretion of the supervising dentist.
Although it is the legal responsibility of the dentist to diagnosis for sealants placement, the
dentist can then assign the performance of the function with direct supervision. Beginning
January 1st of 2007, the RDA may place pit and fissure sealants under either direct or general
supervision depending upon the discretion of the supervising dentist. This change in supervision
requirements allows the RDA to place and adjust sealants without the dentist being present in the
treatment facility, as long as the dentist has given instruction to perform such a procedure on a
specific patient(s).



                                                 2
Prevalence of caries and the caries process

        The National Institutes of Health, conducted a yearlong study to determine the prevalence
of caries in school children in the United States. According to that study and many others done
by different agencies, occlusal caries account for 88% of all carious lesions experienced by
children in the 6-15 year age group. If you consider that there are five surfaces on each posterior
tooth (facial, lingual, mesial, distal and occlusal) you will determine that occlusal surfaces only
make up about 12-13% of the available tooth surfaces in the mouth, and yet occlusal caries
represent well over ¾ of the total caries experienced by children. Although sealants are most
beneficial to children, they can be of great benefit to adult patients who exhibit deep pits and
fissures or occlusal caries activity. Even those individuals that have had the benefit of systemic
fluoride may need sealants.
        A report by Mary DeSpain DDS, Associate professor at Baylor College of Dentistry,
cites many studies that indicate “current data show a slower rate of caries progression and
delayed onset of the disease resulting from suppression of the caries process by fluoride. The
period from initiation of the enamel lesion through advancement to dentin can be as long as four
years. Consequently, the risk for a first carious attack now extends into early adulthood.”
Occlusal caries in individuals in their early to mid twenties. Many of these individuals have had
the benefit of systemic fluoride as children, but are now showing signs of occlusal caries in deep
pit and fissure areas. We currently place sealants on individuals up to age 30.
        “Evidence from several additional studies lends support to the theory that caries is no
longer primarily a disease of children. In fact, one study suggests that the primary cause of tooth
loss in adults is caries and its sequelae, not periodontal disease, as many believe.”
        Another study showed the need for sealants among military personnel between the ages
of 17-34 years from 33 to 48 percent; a third of the individuals would have avoided Class I
restorations had sealants been placed even as young adults.
        National studies also reveal changes in the pattern of tooth surfaces affected by dental
caries, and the distribution of disease.

       a.      More pit and fissure caries
       b.      More caries in poor and minorities (80% of caries found in permanent teeth are
               found in only 25% of population)
       c.      Poor and minority children experience more tooth loss
       d.      Only 1.5% of children ages 2-11 have had primary teeth sealed
       e.      Fewer second molars are sealed than first molars, despite an equal caries risk

        The Centers For Disease Control and Prevention (CDC) has indicated the following
factors which increase the risk of caries in both children and adults. They are individuals that:

       •       Seek dental care on an irregular basis, have no dental insurance or no access to
               dental services
       •       Have active dental caries
       •       Have high levels of infection with cariogenic bacteria
       •       Have family members with a history of high caries prevalence
       •       Have impaired ability to maintain oral hygiene
       •       Children with a history of caries in their primary dentition
       •       Root surfaces exposed by gingival recession

                                                3
       •       Malformed enamel or dentin
       •       Reduced salivary flow because of medications, radiation treatment or disease
       •       Low salivary buggering capacity
       •       Presence of orthodontic appliances, or dental prostheses
       •       Frequent intake of high carbohydrate and sugar containing foods
       •       Inadequate exposure to systemic and topical fluorides
       •       Child is far less likely to have sealants if patents do not have a college education

Dental Disease Process – The Easy Version

        The formation of dental caries is a complex disease process. There are several
components to this process, and in addition, constantly evolving information about how dental
disease occurs. Most researchers agree that caries is the progressive loss of tooth minerals,
followed by bacterial invasion into the demineralized tooth structure. There are several factors
that contribute to the disease process, they are:

       •       Presence of acid tolerant bacteria, that adhere to tooth structure
       •       Presence of dietary sugars that change the thickness and chemical nature of
               plaque
       •       Frequency of dietary sugar intake, particularly sucrose, glucose, and fructose
       •       Oral hygiene frequency and efficiency
       •       The presence of adequate saliva flow

        Dr. Per Axelsson, a noted researcher and dentist in Sweden is considered one of the most
respected authorities on dental disease. In his textbook, Diagnosis and Risk Predictions of Dental
Caries, Dr. Axelsson includes several additional factors that contribute to the formation of dental
plaque. Among these factors are:

       •       The anatomy and surface morphology of the dentition
       •       Quality of saliva
       •       The exposure to chewing forces and abrasion from foods
       •       The eruption stage of the teeth

        All of these additional factors have a significant effect on dental disease. Axelsson‟s book
includes studies performed by Kohler et al, which showed that mother/caregivers who have high
S Mutan bacteria levels in their saliva transmit the bacteria to their babies. These infants will
experience a higher caries rate in their first primary molars as compared to infants from
mothers/caregivers that have good oral hygiene. The same study also showed that one year old
infants with plaque and gingivitis will develop several caries during the following year. All of
these studies show that dental disease is an infectious disease and also preventable.
        Axlesson‟s studies additionally show molars are much more likely to experience occlusal
caries than premolars. The reason?...... Molars have a significantly longer eruption period (14-16
months) than premolars (1 to 2 months). Since the molars take much longer to erupt they are not
in occlusal contact, and are not exposed to chewing forces. This lack of occlusal contact, allows
for heavy plaque accumulation. Heavy plaque can be found in particular in the distal and central
fossae since they are the last areas to erupt. After complete eruption, there is a reduction in
plaque simply because of abrasion from normal mastication (chewing) forces.

                                                 4
        Newly erupted teeth are also more susceptible to caries until they reach a secondary
maturation period, which takes about two years from the completion of eruption.
        Of all the age groups at risk for dental caries, the 11 to 14 year old group represents the
greatest risk. Not only do they have the largest number of intact tooth surfaces, but they also
have the highest number of tooth surfaces at risk. These risk factors include:

        •       newly erupted, immature teeth
        •       currently erupting teeth
        •       often high exposure to fermentable carbohydrates (sugars)
        •       often poor oral hygiene habits
All of these factors go a long way to show that both children and young adults can benefit from
pit and fissure sealant placement as part of a preventive dental program.

A Bit About Tooth Development

       Teeth begin to develop inutereo between the fifth and sixth weeks of pregnancy. Tooth
development is divided into the following distinct groups. (See MOD page 86 Table 8-1).

Initiation

         Initiation begins with the formation of a “tooth germ”. This tooth germ produces the
tissues of the tooth. This primary stage of development is also referred to as the „bud stage”. In
this stage the oral epithelium (the primary dental lamina), thickens and grows downward into the
underlying tissues to form a “bud shape”. This process continues toward the posterior area until
all the primary tooth buds are formed in both the maxillary and mandibular jaws.

Proliferation

         In this stage, tissues begin to form into specific groups. The first cell grouping is the
enamel organ which produces enamel. These cells multiply (proliferate) at a very fast pace and
start to create a “cap” shape. The mesoderm produces connective tissue within the cap which will
eventually produce specialized cells/tissues.

Histodifferentiation

        As cells increase in number, they begin to form layers into a bell shape. Later these cells
become specialized and form ameloblasts to make enamel, and odontoblasts which produce
dentin. Seperating these two cells is a basement membrane.

Morphodifferentiation

        During morphodifferentiation the cells begin to specialize in shape. As the tooth germ
develops the bone cells begin to form into both the mandibular and maxillary jaws. Later the
nerves, blood vessels and teeth will become incorporated into this bone tissue. By the fifth month
inutero, the hard tooth tissues form starting with dentin and then enamel.




                                                  5
Apposition

        Apposition is thought of as the final stage of tooth formation, though not complete
development. During apposition, both dentin and enamel increase in layers until the tooth has a
complete shape. Much like a tree that grows in layers, the tooth develops from the incisal or
occlusal surface toward the root apex in layers. This means that the crown forms first and than a
portion of the root is formed. The entire root will not be completely formed until long after the
tooth is completely erupted into the mouth.

Calcification

        Calcification of the dentin occurs as the dentin develops. Once a layer of dentin is
produced it will begin calcification. As soon as the next layer is produced, the previous layer
begins to calcify. Dentin will continue to be produced throughout the life of the tooth. Enamel
however, is only produced and mineralized during the calcification stage. Once the process is
complete, no additional enamel is produced.
        This last stage of tooth development is the actual eruption of the tooth into the mouth.
Because tooth eruption occurs throughout life, this process has been divided into active and
passive stages.

Eruption
Active Eruption

        Active eruption begins once the crown and portions of the root are finished developing.
At that time the tooth will move from its placement in the jaw into the oral cavity. The active
eruption process will continue until the tooth meets another tooth (occludes) in the opposite arch.
The opposing tooth is referred to as an antagonist tooth. It is at the active eruption stage that we
should consider placement of pit and fissure sealants. The teeth should be sufficiently erupted to
allow for a dry area of placement, but placement should ideally occur as soon as possible.

Passive Eruption

       I always tell my students that teeth are very friendly… they like to touch each other.
Passive eruption can occur throughout the life of a tooth. For example, if a second maxillary
molar is extracted, the mandibular tooth will try to erupt further into the mouth to contact the
opposing arch. Teeth also passively erupt in response to wear and other factors.

Tooth Eruption

       Since sealants are most effectively placed as soon as the teeth are fully erupted, it is
important to know the various eruption dates for both primary and permanent posterior teeth.
The MOD has photographs of the primary dentition and the gradual development and eruption of
permanent teeth from ages 3-9 years of age. These photos graphically display the long process of
development and eruption. Eruption dates for permanent teeth are also included in the MDA. It is
important for you to make these eruption dates part of your general dental knowledge. (See
MOD pages 90 & 91 Fig. 8-11 A & B, and page 92 Fig. 8-13 & 8-14).

                                                 6
Tooth Morphology

         All teeth develop from individual lobes. Lobes are the separate divisions of the tooth that
join together to eventually form the entire tooth. As mentioned in the introduction, it is the
incomplete joining of these lobes that creates deep pits and fissures. Each tooth is formed from a
minimum of four lobes. For example, the maxillary premolars are formed from four lobes. The
mandibular second premolars (bicuspids) however, are formed from five lobes. The number of
lobes involved in the formation of all molars, is directly related to the number of cusps the tooth
has. If a molar has four cusps, it was developed from four lobes.
         A maxillary central incisor is formed from four lobes. Three lobes form the bulk of the
crown and create mamelons (the little bulges along the incisal edge), the fourth lobe forms the
singulum, located at the gingival third of the tooth on the lingual. Sometimes the fourth lobe does
not completely fuse and a pit occurs at the cingulum. A sealant can be placed in that area to help
prevent decay.
         My friend Barbara Cancilla, the former Director of the Dental Assisting Program at the
College of Marin utilizes a great analogy for explaining lobes and the formation of pits and
fissures. Imagine placing four or five pieces of biscuit dough tightly together on a baking sheet
(these represent the individual separate lobes of the teeth). Now bake the biscuits. You will have
a giant fused biscuits with grooves. The place where the grooves come together or cross is a pit.
If the grooves don‟t completely fuse, you have a fissure. If you follow that analogy a bit further,
you can imagine drizzling butter and jelly down into the un-fused biscuits. That would be the
sealant. Of course you can‟t eat a sealant, but I bet you wish you had some nice homemade
biscuits with butter and jelly right now!

Components of the Occlusal Surfaces of Posterior Teeth

        The following pages contain detailed descriptions of the morphology of the first and
second premolars, and first and second molars in the permanent dentition. Although we do not
expect you to identity every aspect of each tooth, you are expected to know basic occlusal
morphology, since it directly relates to your ability to correctly place and evaluate pit and fissure
sealants. To help you get started, here is another analogy.
       Think of the occlusal surface of a tooth as a mountain range that surrounds a valley, in the
bottom of the valley is a river bed. The mountains have inclined sides and a top or mountain
ridge. Our job is to place sealant in the river bed without getting the sealant up onto the inclined
sides of the mountain ridges. BUT, we need to make sure that all the river bed is covered with
sealant.




                                                  7
       On a tooth,

       A. the river bed is the grooves (fissures and pit)
       B. the inclined sides of the mountain range are the cusps inclines
       C. the mountain ridges/tops are the marginal ridges
       D. the valley is the fossae




         When placing etchant and sealant, keep the material into the pits and fissures without
extending the material up onto the cusp inclines or marginal ridges. Our job is to create rivers of
sealant in the river beds and not make a lake that extends up the mountain side!

       Although each type of tooth has different morphology, you should be to identify at lease
the least the following basic structures

     All posterior teeth have the following general structures:
           Pits
           Grooves
           Fossae
           Ridges

        We know that there are many variations for each tooth type. Your job is to recognize the
basic structures even when they differ from ideal. It will be your job to learn the specific patterns
of each tooth type. Knowing each pattern type will greatly help you correctly place sealants. By
knowing each pattern you will cover everything you need to cover, but won‟t place material in
areas that will cause high occlusion or sealant failure.

                                                  8
                               MAXILLARY 1st PREMOLARS
                                        #5 & # 12
                                 (erupts at age 10-11 yrs)

                                    Occlusal View of Crown

1. Hexagonal shape – 6 sides
       a. Wider buccolingually than mesiodistally

2. Cusps (2) (Mountains):
       a. Buccal cusp
            i. Largest
           ii. Set to the distal
       b. Lingual cusp
            i. Smaller
           ii. Set to the mesial

3. Incline planes (Sides of Mountains):
       a. Each cusp has 4 incline planes, named for location: mesiobuccal, mesiolingual,
          distobuccal, distolingual
              i. Mesiolingual & distolingual of the buccal cusp are the only functional planes
                 during occlusion
             ii. All incline planes of lingual cusp are functional during occlusion

4. Ridges (The top of the mountain):
      a. Cusp ridges:
             i. Each cusp has 4, named for location – mesial , distal, buccal, lingual.
      b. Mesial marginal ridge – shorter and straighter than distal marginal ridge.
             i. Mesial marginal groove can create dip in outline
      c. Distal marginal ridge – shorter, less prominent
      d. Transverse ridge – see page 13 following formed by the buccal triangular ridge of
         the buccal cusp (lingual cusp ridge of buccal cusp) and the lingual triangular ridge
         (buccal cusp ridge of lingual cusp) of the lingual cusp.

5. Fossae (Valley), Pits and Grooves (River Bed):
      a. Central groove
              i. Extends mesiodistally across occlusal table
             ii. Evenly divides tooth buccolingually
            iii. Ends in mesial pit & distal pit
            iv. Deep, sharply defined, V- Shaped
     b. Masial triangular fossa
              i. Deeper but smaller than distal fossa
             ii. Contains:
                    1. Mesial pit
                    2. Developmental grooves present:
                         a. mesiobuccal triangular, mesiolingual triangular, and mesial
                            marginal (crosses mesial marginal ridge onto mesial surface)

                                                9
     c. Distal triangular fossa
              i. Shallower but larger than mesial fossa
             ii. Contains:
                    1. Distal pit
                    2. Developmental grooves:
                           a. Distobuccal triangular, and distolingual triangular

     d. A few shallow supplemental groves maybe present




                               MAXILLARY 2nd PREMOLARS
                                         # 4 & # 13
                                  (erupts at age 10-12 yrs)

                                     Occlusal View of Crown

1. Oval (rounded) shape
         a. Wider buccolingually than mesiodistally

2. Cusps (2) (Mountains):
         a. Buccal cusp
               i. Largest
              ii. Centered
         b. Lingual cusp
               i. Smaller
              ii. Set to the mesial
3. Incline planes (sides of Mountains):
         a. See maxillary 1st premolar – 4 inclines

4. Ridges (The top of the mountain):
        a. See maxillary 1st premolar

                                                10
5. Fossae (valley), Pits, and Grooves (River Bed):
        a. Central groove
               i. Very short compared to 1st premolar
                     1. Mesial & distal pits close together
        b. Mesial triangular fossa
               i. Smaller than distal fossa
              ii. Contains:
                     1. Mesial pit
                     2. NO mesial marginal groove
        c. Distal triangular fossa
               i. Larger than mesial fossa
              ii. Contains:
                        1. Distal pit
        d. Many shallow supplemental grooves will be present and give tooth wrinkled
           appearance. Unless additional groove have deep fissures, they probably won’t
           need to be sealed.




                                MAXILLARY 1st MOLARS
                                        #3 & #14
                                  (erupts at age 6-7 yrs)

                                   Occlusal View of Crown

1. Rhomboidal shape uneven parallel lines
       a. Wider buccolingually than mesiodistally

2. Cusps (Mountains):
       a. mesiolingual-largest
       b. mesiobuccal-second largest
       c. distobuccal-third largest
       d.distolingual-smallest and most variable of major cusps
       e. possible nonfunctional 5th cusp “cusp of Carabelli” on mesiolingual cusp

                                              11
3. Incline planes (Sides of Mountains):
         a. Four per cusp-named for position
         b. All four functional on mesiolingual and distolingual cusps
         c. Two functional (mesiolingual and distolungual) on mesiobuccal and distobuccal
            cusps.

4. Ridges (The top of mountain):
       a. cusp ridges:
               i. Each cusp has 4 – mesial, distal, buccal, lingual.
       b. Mesial marginal ridge – longer than distal marginal ridge.
       c. Distal marginal ridge- shorter, less prominent.
       d. Transverse ridge- formed by the buccal triangular ridge of the mesiolingual cusp and
           the lingual triangular ridge of the messiobuccal cusp.
       e. Oblique ridge- formed by distal triangular ridge of the mesiolingual cusp and the
           lingual triangular ridge of the distobuccal cusp.

5. Fossae (Valley), Pits, and Grooves (River Bed):
       a. Central fossa (mesial to oblique ridge):
                i. Contains central pit at deepest portion
                       1. Divides central groove into mesial groove and distal groove
                       2. At junction of 3 developmental grooves:
                               a. buccal, mesial and distal
        b. Mesial triangular fossa (distal to mesial marginal ridge)
                i. Contains mesial pit
                       1. At junction of 4 developmental grooves:
                               a. mesial, mesiobuccal triangular, mesiolingual triangular, and
                                  mesial marginal
        c. Distal triangular fossa (mesial to distal marginal ridge)
                i. Contains distal pit
                       1. At junction of 5 developmental grooves:
                                a. distal, distolingual, distobuccal triangular, distal marginal,
                                   and distal lingual
               ii. Contains distal groove
                        1. Extends from central pit across oblique ridge to the distal pit
                                a. Sometimes referred to as the transverse groove of the
                                   oblique ridge
         d. Distal fossa (linear depression runs parallel and distal to oblique ridges
                i. Contains distolingual groove
         e. Supplemental grooves may be present
         f. Lingual groove may end in pit on lingual surface




                                                12
                                MAXILLARY 2nd MOLARS
                                         #2 & #15
                                 (erupts at age 12-13 yrs)


                                   Occlusal View of Crown


1. 2 types:
         i. Rhomboidal – Most common type. Very similar to 1st molar, but more accentuated
        ii. Heart- shaped – less common type. More similar to maxillary 3rd molar.
                1. Distolingual cusp is very small or absent.
                   Distolingual groove is confined to the occlusal table.


2. Cusp, ridges, fossae, pits, and grooves very similar to the 1st molar
        1. except:
                i. Oblique ridge may be less prominent than on 1st molar
               ii. Usually has more supplemental groves than 1st molar
              iii. Distolingual groove may end in pit on lingual surface

                 IMPORTANT NOTE
                 The distolingual groove and pit are probably the most often missed area
                 For sealant placement.


3. Mesiolingual cusp is largest cusp on 2nd molar




                                              13
                       MANDIBULAR 1st PREMOLARS
                                #21 & # 28
                             (erupts at 10-12 yrs)

                                Occlusal View of Crown

1. Diamond shape

2. Cusp (2) (Mountains):
      a. Buccal cusp
             i. Larges
            ii. Centered over
                long axis of tooth
           iii. Set to the mesial
      b. Lingual cusp
             i. Much smaller
               (half as big as
               buccal cusp or
               smaller)
            ii. Nonfucional
           iii. Set to the mesial

3. Incline planes (Side of Mountain):
       a. Each cusp has 4 incline planes, named for location: mesiobuccal,
          mesiolingual, distobuccal, distolingual
             i. All incline planes of buccal cusp are functional during occlusion

4. Ridge (The top of the mountain):
      a. Cusp ridges:
             i. Buccal triangular ridge
            ii. Lingual triangular ridge
      b. Mesial marginal ridge
             i. Shorter than distal marginal ridge.
            ii. Slopes buccolingually at a 45 degree angle
           iii. Dip created by mesiolingual groove
      c. Distal marginal ridge- shorter, not as steep of slope.
       IMPORTANT NOTE
       The buccal triangular ridge and the lingual triangular ridge often join together
       In the middle of the central groove dividing the groove into two separate fossae.
       When placing a sealant in this area you will usually place two separate dots of material.
       We will probably refer to this as “snake eyes”.

5. Fossae (Valley), Pits, and Grooves (River Bed):
       a. Central groove
                 i. Extends mesioldistally across occlusal table
                ii. Ends in mesial pit & distal pit



                                                14
      b. Mesial fossa
                i. Shallower and smaller than distal fossa
               ii. Contains:
                       1. Mesial pit
                       2. Developmental grooves present:
                              a. mesiobuccal triangular, mesiolingual,
                                 (Crosses mesial marginal ridge)
       c. Distal fossa
                i. Deeper and larger than mesial fossa
               ii. Contains:
                      1. Distal pit
                      2. Developmental grooves:
                              a. Distobuccal triangular, distolingual triangular, distal
                                 marginal




                        MAN DIBULAR 2nd PREMOLARS
                              # 20 & # 29
                           (erupts at age 11-12 yrs)

                            Occlusal View of Crown

1. Square (or rounded) shape
       a. 3 types
               i. “Y” (most common 55%)
                  “U”, “H”

                                             15
2. Cusps (Mountains)
       a. (“Y” type-3):
                   3 cusp type “Y”
                   2 cusp type “U”
              i. Buccal cusp
                   1. Largest
                   2. Set buccally (not centered over long axis of tooth as with 1st
                      mandibular premolar)
              ii. Mesiolingual cusp
                    1. Smaller than buccal cusp, larger than distolingual cusp
              iii. Distolingual cusp
                    1. Smallest of all 3 cusp
       b. (“U” & “H” types – 2):
              i. Buccal cusp
                       1. Largest
              ii. Lingual cusp
                       1. Smallest

3. Incline planes (Sides of Mountains):
        a. See mandibular 1st premolar

4. Ridges (The top of the mountain):
       a. cusp ridges:
               i. Each cusp has 4, named for location – mesial, distal, buccal, lingual.
       b. Mesial marginal ridge
       c. Distal marginal ridge
       d. Transverse ridge (none on “Y”
           shape)

5. Fossae (Valley), Pits, and Grooves (River Bed):
       a. “Y” type:
               i. Central groove
                       1. Central pit, mesial pit, and distal pit
               ii. Lingual groove
                       1. separates mesiolingual and distolingual cusps
               iii. Mesial groove
                       1. Contains:
                               a. Mesial pit
                               b. Developmental grooves present:
                                       i. mesiobuccal triangular, mesial marginal
               iv. Distal triangular fossa
                       1. Contains:
                               a. Distal pit
                               b. possible developmental grooves:
                                       i. Distrobuccal triangular, distolingual
                                          triangular, distal marginal



                                                 16
     b. “U” & “H” type:
            i. Central groove
                     1. Mesial pit, distal pit
            ii. Mesial fossa – circular
                     1. Contains:
                             a. Mesial pit
                             b. May have some supplemental grooves
            iii. Distal fossa – circular
                     1. Contains:
                             a. Distal pit
                             b. May have some supplemental grooves




                            MANDIBULAR 1ST MOLARS
                                    #19 & #30
                              (erupts at age 6 – 7 yrs)

                                 Occlusal View of Crown

1.   Rectangular (or pentagonal) shape
           a.      Wider mesilodistally than buccolingually

2.   Cusps (Mountains):
           a.    5 functional cusps
                 i. mesiobuccal – largest
                 ii. mesiolingual – second largest
                 iii. distolingual – third largest
                 iv. distobuccal – smallest of major cusps
                 v. distal – smallest minor cusp

                                           17
3.   Incline planes (Sides of Mountains):
            a.     Four per cusp – named for position

4.   Ridges (The top of the mountain):
           a.      Cusp ridges:
                   i. Each cusp has 4 – mesial, distal, buccal, lingual.
           b.      Triangular ridge:
                   i. Each cusp has one
           c.      Mesial marginal ridge – longer than distal marginal ridge.
           d.      Distal marginal ridge – shorter, less prominent.
           e.      Transverse ridge – can have one formed by the mesiobuccal triangular
                   ridge and the mesiolingual triangular ridge (can have 2nd transverse ridge
                   if distal cusp is absent)
           f.      Oblique ridge – None

5.   Fossae (Valley), Pits, and Grooves (River Bed):
            a. Central fossa
                    i. Contains central pit
                            1. “Y” shaped groove pattern formed around cusps by the
                                junction of mesiobuccal groove, distobuccal groove, and
                                lingual groove
            b. Mesial triangular fossa (distal to mesial marginal ridge)
                    i. Contains mesial pit
                            1. Junction of mesial groove, mesiobuccal groove, mesiolingual
                               groove, and mesial marginal groove
            c. Distal triangular fossa (mesial to distal marginal ridge)
                            1. Contains distal pit
                                    a. Junction of distal groove, distolingual groove, and
                                      distal marginal groove
            d. Supplemental grooves may be present
            e. Mesiobuccal groove and distobuccal groove may end in a pit on the buccal
               surface




                                            18
                             MANDIBULAR 1ST MOLARS
                                      #18 & #31
                              (erupts at age 11 – 12 yrs)

                                  Occlusal View of Crown

1.   Rectangular shape
           a. Wide mesiodistally than buccolingually

2.   Cusps (Mountains):
           a. 4 equal sized cusps
                  i. mesiobuccal, mesiolingual, distobuccal, distolingual

3.   Incline planes (Sides of Mountains):
            a. Four per cusp – named for position

4.   Ridges (The top of the mountain):
           a.      Cusp ridges:
                   i. Each cusp has 4 – mesial, distal, buccal, lingual.
           b.      Triangular ridge:
                   i. Each cusp has one
           c.      Mesial marginal ridge – longer than distal marginal ridge.
           d.      Distal marginal ridge – shorter than mesial.
           e.      Transverse ridge (2)
                           i. has one formed by the mesiobuccal triangular ridge and the
                              mesiolingual triangular ridge, and the other by the distobuccal
                              triangular ridge and the distolingual triangular ridge
           f.      Oblique ridge – None

5.   Fossae (Valley), Pits, and Grooves (River Bed):
            a. Central fossa
                    i. Contains central pit
                            1. “Cross” shaped groove pattern formed by the buccal groove
                                and lingual groove crossing the well defined central groove
            b. Mesial triangular fossa (distal to mesial marginal ridge)
                    i. Contains mesial pit
            c. Distal triangular fossa (mesial to
               distal marginal ridge)
                            1. Contains distal pit
            d. Supplemental grooves
               may be present
            e. Buccal groove may end in a pit
              on the buccal surface




                                            19
Oral Fluids

    Since successful sealant placement is greatly
dependent on the control of oral fluids, it is important
to understand both saliva glands and saliva itself.

    First, there are three basic types of oral fluids.

Serous        Serous secretions are thin.
              Watery and clear.

Mucous        Mucous secretions are
              thick, viscous water and
              inorganic salts that help
              protect and lubricate oral
              tissues.

Mixed - Serous + mucous
        These oral fluids are secreted by
three major saliva glands, and several
minor glands located throughout the
mouth. The location of the saliva glands and ducts is important to understand since it will be your
job to isolate the teeth from there fluids during sealant placement as much possible.

Parotid Gland
       The larges to the salivary glands is the parotid. It is located on the side of the face, in front of
and below the ear. The gland releases fluids through the Stenson‟s duct. Stenson‟s duct may be
seen as a small hole on the inside of the cheek adjacent to the maxillary first molars. Fluids
produced by the parotid gland are purely serous. Because the fluid is serous it will not be thick and
ropy like fluids in other parts of the mouth.
Dri-Aid or other device placed over the duct will usually work well in this area to reduce salvia
contamination when placing sealants on both the maxillary and mandibular arches. A viral
infection of this gland is called munps.
Submandibular Gland
        Underneath the inferior border of the mandible is small walnut sized gland called the
submandibular gland. The gland releases fluid through the Wharton‟s duct and produces about
20% mucous and 80% serous fluids. You can locate the Wharton‟s within the soft tissues
underneath the tongue. These are the ducts that secrete fluid when someone is speaking. Isolation
in this area is best accomplished with cotton rolls and high volume suction or rubber dam.
Sublingual Gland
         The smallest of the major salivary gland is the submandibular gland. It is located on the
floor of the mouth, beneath the sublingual mucosa and can have as many as 20 small ducts. This
grouping of ducts is referred to as the ducts of Rivinus and Bartholin. Although these glands
secrete a mixture of both fluids, they are primarily mucous secretions. Again the openings for these
ducts are located beneath the tongue. Isolation is best accomplishmplished with cotton rolls and
high volume suction or rubber dam.



                                                   20
Minor Salivary Glands

Labial Glands
             The labial glands are buried deep within the tissue of lips. They have many small
ducts with open directly onto the lips. Although they are a mixture of fluids, they are primarily
mucous producing.

Buccal Glands
        Buccal glands are located within the cheeks and are similar to the labial glands in both
secretions and numbers.

Palatine Glands
         The palatine glands are located across the posterior third of the hard palate and across the
entire surface of the soft palate. The ducts are numerous and often visible. They secrete pure
mucous fluids. It is only possible to isolate these numerous ducts with rubber dam or cotton rolls
with Garmer‟s clamps
Lingual Glands
               Anterior Lingual Glands
                       The glands are located at the apex of the tongue and the ducts secrete
primarily mucous fluids onto the ventral surface of the tongue.
                Lingual Glands of Von Ebner
                        The glands re located beneath the vallate paillae are only serous fluids.
                Posterior Lingual Glands
                        The glands are located on the posterior portion of the tongue, near the
tonsils, and secrete only mucous fluids.


A Brief Tour of Occlusion

       Fully understanding all of the principals of occlusion could easily take years. Even many
dentists do not fully understand this concept, so we are not asking you to have more than a basic
understanding of occlusion.
       You are allowed to both place sealants, and adjust the sealant if it is too high in occlusion.
The most ideal situation would be to avoid placing too much sealant in the first place. That will be
an important goal of the course you will be taking. To help avoid high occlusion we will be
teaching you to use re articulating paper to determine “occlusal stop” prior to placing a sealant.
This should go a long way toward reducing the number of sealants that might need to be adjusted.
Even so, high sealants will probably occasionally occur.
       Centric occlusion occurs when the maxillary and mandibular jaws close into a position that
provides the most stable contact of the occluding surfaces of the teeth. As you probably already
know, the entire occusal surface of the maxillary teeth does not contact the entire occlusal surface
of the mandibular teeth. Instead cusp ridges fit into various grooves of the opposite arch. We will
be giving you a diagram of occlusal stop in class for a reference. For now watch your dentist as
they utilize articulating paper to check occlusion and note how the teeth come together.




                                                 21
Adhesive/ Bonding

        Although there is technically a difference between the terms adhesive and bonding, we will
use them interchangeably. In dentistry we utilize a lot of materials to “bond” or hold things
together. We use both “micromechanical” (small) and “macromechanical” (large) bonding
techniques.
        Recently I had a cabinet door in my kitchen pull apart. I used a wood glue to repair the
door. In order for the glue to work, the wood surface had to be visibly rough or irregular of at least
feel rough. The glue was able to hold the two surfaces together because the glue flowed into the
irregular surfaces of the wood as liquid, and then in hardened. The hardened glue locked into the
irregular surfaces of the two pieces of wood and created a bond between the two surfaces repairing
the door.
         In dentistry we use the same kind of macromechanical bonding to hold crowns and fixed
bridges onto teeth. The dental cement locks into the rough inner surface of the crown and the
roughened tooth surface. We can even create additional roughness on the tooth surface with
etchant. We sometimes refer to dental cements as luting agents, but they really work in the same
way as the glue I used for my cabinet door. The difference is that in dentistry, we have to use
adhesive materials that can survive in the wet oral environment.
        Some procedures that we do in dentistry, such as sealants, require “micromechanical”
bonding. With this type of bonding, we won‟t be able to see or even feel the roughness. Because
teeth are not naturally rough, we will need to create the roughness. This is where “etchant” comes
into the picture. With etchant (ortho-phoshoric acid), we can create a significant number of
irregular surface surfaces, far more than you would see with macromechanical bonding. Even
though the irregular surfaces are microscopic, there are many rough surfaces. Because there are so
many irregular surfaces spread across the entire occlusal surface of the tooth, the bond between the
tooth and sealant will be very strong. (See MDA pg. 733 fig 44-6 & 44-7).

        For sealant and most other bonded composite restorations, we use a 35-37%
orthophosphoric acid to remove part of the material between the enamel rods. The etchant can
dissolve either the core around the rod, the rod itself or a mixture of both, the acid etchant
dissolves away the calcium and phosphate ions, leaving behind a rough surface. The surface
texture is often referred to as micropores the surface will have a frosted look as in the photos in the
MDA.

Sealant Material Composition
        Sealants are very similar in composition to composites and bonding agents. Simply put,
they are a combination of resin (plastic) and many of the components found in glass. We list all of
the chemical names found in sealants, but it would not make you any better at pacing sealants. So
listed below are a few important items. Sealants contain:
        ● several types of resins (monomers) which act as a matrix to hold other components
            together and provide the bulk of the material
        ● Titanium Dioxide for white colorization
        ● Several components that cause photo-initiation (light cure)
        ● Several fillers for stretngh
               ○ Optional fluoride
               ○ Optional coloring for ease of application



                                                 22
Sealant failure

        There are many things that can cause a sealant to fail. However the two most important
factors are true of any form of adhesion. If the surface of the tooth is not cleaned, or becomes
contaminated with fluids after the etchant is rinsed, a good bond will not occur. The term
“Biofilm” is used today to describe all the different fluids in the mouth, i.e. saliva, blood,
crevicular fluid, pellicle, pladque, etc. If the tooth surface becomes contaminated with biofilm,
the adhesive or bonding agent no longer prepares or roughens tooth surface. Like the cobwebs
and dirt on the wood. Biofilm interferes with adhesion and can cause the bond to fail. Without
the bond, the sealant will fail. It may fail by falling off completely or it may leak, allowing for
decalficaiton or caries to form underneath the surface of the sealant.

        There are several additional reasons besides surface contamination why a sealant might
fail. They can include.
        ● Outdated material
        ● Material exposed to high heart
        ● Exposure to Eugenol containing products
        ● Incorrect curing time
        ● Malfunctioning curing light
        ● Manufacturer‟s error
        ● Inadequate etch
        ● Presence of demineralized tooth structure
        ● Incorporation of bubbles into the mix
        ● Incomplete removal of cleaning debris from the pits and fissures before etch
        ● Teeth not completely erupted
        ● Presence of an operculum

      Just remember, that the most common reason for failure is because of an incomplete bond,
caused by biofilm contamination after the etchant is placed, rinsed and dried.


Out dated material
Outdated material will not polymerize properly and can cause the sealant to fail

Material exposed to high heat/Eugenol
Sealant material exposed to high heat or extreme cold will not properly flow and will fail to
correctly polymerize. Sealant material should be stored and used at room temperature. 70-75
degrees F. Sealant material should never be stored in close proximity to eugenol-containing
products such as IRM, periodontal dressing and some luting cements. Eugenol interferes with
the polymerization process and cause the sealant to not fully cure. The face that the sealant has
not fully cured will not necessarily by visible at the time of placement.

Incorrect curing time/Malfunctioning curing light
Incorrect curing time or a malfunctioning curing light can also cause sealant failure. It is very
important to always check the function of a curing light prior to each use. Meters for measuring
visible light output are available and should be used in every office. Many new curing lights now
have built-in meters.

                                                 23
Inadequate etch
Inadequate etch can occur when too much or too little time is use for etching. Etching may also
be compromised if the etchant is too vigorously applied. Sealant retention relies on a roughened
enamel surface created by the etchant. If too little time is used, the enamel will not have enough
surface retention to hold the sealant. If the etchant remains on the teeth too long or is to
vigorously rubbed onto the surface, the fragile lattice-work structure created by the etchant will
actually be reduced, creating less likelihood that the sealant will adhere to the tooth for very long.
Surface contamination
The leading cause of sealant failure is thought to be saliva contamination after the ectchant has
been removed and dried. The pellicle contained in saliva acts to cover the etched surface, and
cause the sealant to adhere to the pellicle instead of the enamel.
Presence of demineralized tooth structure
Some research has shown a connection between sealant failure and demineralized tooth structure.
The theory indicates that etching demineralized tooth structure will create less surface retention
for the sealant to adhere to the enamel, thus causing sealant failure.
Incorporation of bubbles into the mix
Bubbles incorporated into the mix while mixing auto polymerizing sealant can weaken the
sealant and cause it to fracture or detach. Likewise bubbles can be present in pre-loaded syringes.
It is best to store the syringes facing downward and dispense a small amount of sealant onto 2x2
gauze or mixing pad before applying the sealant to the tooth surface. If bubblers are noted during
application they should be eliminated from the surface. The tip of the applicator or an explorer
can be used for this purpose.
Incomplete removal of cleaning debris from the pits and fissures before etch
The presence of remaining prophy paste from coronal polish or bicarbonate of soda from a
prophy jet may be responsible for some sealant failures. The bicarbonate of soda can be
particularly problematic because it can neutralize the effects of the acid etch. For this reason,
most sealant manufactures are now recommending a double etch or the use of a hydrogen
peroxide wash/rinse/dry before etchant is placed. The procedure that seems to create the best
result is a dry toothbrush. The surfaces can be brushed with a dry toothbrush and rinsed/dried
prior to etchant or etchant/bond combination. Some manufacturers are recommending that teeth
do not be pre-cleaned at all.
Tooth not completely erupted/Presence of an operculum
Since the leading cause of sealant failure is thought to be saliva contamination after the ectchant,
it is important that the tooth is sufficiently erupted to control crevicular fluids from
contaminating the tooth surface. If an operculum is still present, it is almost impossible to keep
the tooth dry, and you can almost guarantee sealant failure.


Different Techniques of Sealants
You will be learning two different techniques to apply pit and fissure sealants. The first
technique is the traditional etch and seal technique. This technique has been used for many years
to apply both sealants and place composite restorations. The second technique is one that we feel
is a superior and easier way to place sealants. It utilizes a combination etch/primer/bond and then
the sealant. Both products are cured together. This newer technique has very good retention rates
equal to or better than the traditional technique and is faster and simpler to complete.




                                                 24
1. Technique for Application of sealant
Check air / water syringe, function of curing light and assemble all armentaria
1.    Below a jet of air from syringe onto a glove or mirror. If small droplets are seen the
      syringe must be adjusted so only air is expressed. Any moisture contamination during
      certain stages of this procedure will compromise the integrity of a sealant.
2.    Check light out – put of curing light with light monitor. Improper light cure will cause
      sealant failure.
3.    Make sure you have all need items to place a sealant including, sealant, etch and tips for
      both and/or etch/bond material, floss, basic set – up, articulating paper, dicoid/cleoid for
      adjustment, suction, air/water syringe, cotton rolls and holder, dri-tips, toothbrush, curing
      light, barriers, micro brushes, etc.

2. Select Teeth
Teeth must be sufficiently erupted so that a dry field can be maintained. The morphology of the
pits and fissures should be deep.

3. Clean Enamel
Thoroughly clean teeth to remove plaque and debris from enamel surfaces and fissures. Rinse
thoroughly with water.
Note: Do not use any cleaning medium that may contain oils. If using an air – polish device that
utilizes sodium bicarbonate for cleaning, the etching step should be repeated a second time, or
3% hydrogen peroxide should be applied to the surface for 10 second to neutralize the sodium
bicarbonate, and then thoroughly rinsed with water prior to applying etch. (We will be using a
toothbrush for both efficiency and to avoid problems associated with other techniques.)

4. Dry Teeth and Check Occlusal Stops
Dry the teeth to remove excess water. Use RED articulating paper to verify the occlusal stops.
Using this technique will help you avoid overfilling the pits and fissures.

5. Isolate Teeth and Dry
While a rubber dam provides the best isolation, cotton rolls used in conjunction with isolation
shields such as Dri–tips are acceptable. Use saliva ejection device or high volume evacuation,
including a Lingua – fix.

6. Etch Enamel or Etch/Bond
Technique 1. Apply etchant to all enamel surfaces to be sealed, extending just beyond the
anticipated margin of the sealant. Do not etch the entire surface of the tooth. Etch for a minimum
of 20 seconds, but no longer than 60 seconds.
Technique 2. If using etch/bond (prompt – L – pop) vigorously rub the surface for a full 15
seconds and gently apply air across the surface to thin down the material. Skip to step number 8.
Sealant Application.

7. Rinse Etched Enamel
Thoroughly rinse teeth with air/water spray for at least 10 – 15 seconds to remove etchant.
Remove rinse water with suction. Do not allow patient to swallow or rinse. If saliva contacts the
etched surfaces, re-etch for 10 seconds and rinse.



                                                25
8. Dry Etched Enamel
Gently dry the etched surfaces. Air should be oil and water free. The dry etched surfaces should
appear as a matte frosty white. If not repeat steps 6 and 7.

DO NOT ALLOW THE ETCHED SURFACE TO BE CONTAMINATED.
Clinical studies have clearly shown that moisture contamination of these surfaces is the main
cause for failure of pit and fissure sealants. Immediately apply sealant.

9. Apply Sealant
Using the syringe needle tip, introduce a dot of sealant into the central groove of the tooth, now
hold the syringe like a pen and use the tip to spread the sealant into each pit and fissure area. Do
not let sealant flow beyond the etched surfaces. Stirring the sealant with the syringe tip during or
after placement will help eliminate any possible bubbles, and enhance the flow into the pit and
fissures. Cure the sealant by exposing it to light from a Curing Light. Make sure you have
validated the function of the curing light. A 30-second exposure is needed for each surface. The
tip of the light should be held as closely as possible to the sealant (1-2 mm), without actually
touching the sealant. When set, the sealant forms a hard, opaque film light yellow in color with a
slight surface inhibition.

10. Evaluate Sealant
Inspect sealant for complete coverage and voids. If surface has not been contaminated, additional
sealant may be added. If contamination has occurred re-etch, rinse, and dry prior to placing
more sealant.

11. Dismissal
Wipe the sealant with a cotton applicator to remove the thin sticky inhibition film on the surface.
Check occlusion and adjust if required. Instruct patient not to chew ice.


Curing Light
         The incandescent blue light in a traditional curing light has appropriate filtration at the
light source to eliminate any stray ultraviolet radiation. Although there is minimal potential for
retinal damage, caution and eye protection should always be used by the operator, patient &
assistant. Devices such as special tinted glasses, large paddles and small shields that fit over the
end of the light rod are available for this purpose. One of these devices should always be used.
         Since the success of a sealant is dependent on a proper cure (photo-initiation), the curing
light should be checked before it is used on each patient. Light cure testers are often included
with the light unit. If you do not have a built-in testing device, a handheld unit can be purchased
to check all of the curing lights in your practice.
         If sealant or composite material has adhered to the end of the light rod, the intensity of
the light will be reduced. This light reduction could affect the cure of the sealant, and may cause
it to fail. Cleaning kits are available to maintain the light rod, and should be routinely used.




                                                 26