Transcript No Slide Title

PREVENTION V
PIT AND FISSURE
(Dental)
SEALANTS
HISTORY
• The concept of sealing the fissures of teeth is over 100
years old. In 1895, Wilson, described in Dental Digest the
use of oxyphosphate cement to seal fissures.
• Contemporary pit and fissure sealants were introduced into
clinical dentistry in 1967 by Michael Buonocore of the
Eastman Dental Center, Rochester.
• Dr. Buonocore is credited with developing the field of
adhesive dentistry through his introduction of the concept
of acid etching of tooth enamel, and his documentation of
the ability of resin materials to ‘adhere’ to such etched
enamel surfaces.
• The effectiveness of pit and fissure sealants as a preventive
tool was recognized with provisional approval by the
American Dental Association Council on Dental Therapeutics
in 1971; full approval came in 1976.
• Since then the use of pit and fissure sealants, now generally
referred to as dental sealants, has increased steadily.
SEALANT USAGE
• Surveys show an increase in sealant use among dentists from
38% in 1974 to as high as 90-95% of dentists in recent
surveys.
• The most recent National Health and Nutrition Survey
(NHANES), reported in 2005 that 42% of 6-19 year old
children had caries in one or more of their permanent teeth,
with the majority of lesions being on the occlusal surface.
• 32.2% of 6-19 year olds had one or more sealed permanent
teeth.
• Prevalence of sealed teeth was higher for children 12-15
(37.4%) than children 6-11 (29.5%)
• The prevalence of sealed teeth increased from 19.6 % in
1988-1994 to 32.2% in 199-2002.
• Sealants demonstrated to reduce caries by 84% after one
year and 58% after 4 years.
CARIES PREVALENCE
• As we have discussed, there has been a significant decline in
caries prevalence among school aged children in the past 2030 years.
• Among 2-11 year old children, the NHANES study found
41% had caries in their primary teeth. The prevalence of
caries was higher in Mexican American children (54.9%)
than in black children; and higher in black children (43.3%)
than non-Hispanic white children (37.9%).
• Children from economically disadvantage families (100% of
the federal poverty level—FPL) had a caries prevalence of
55.3%. Caries is correlated with reduced family income.
• There was no change in dental caries prevalence in children
2-11 between 1988-1994 and 1998-2002.
RELATIVE DISTRIBUTION
OF CARIES
• While over time there has been a general reduction in dental
caries, there has also been a change in the relative
distribution, or pattern, of caries on different tooth
surfaces.
• There has been a greater percentage reduction for smooth
surface caries (mesial and distal surfaces) compared to pit
and fissure caries.
• Overall, 88% of the caries in school children occurs in
pits and fissures, and only 12% on the proximal surfaces.
• This differential is related to the more significant impact of
fluorides on smooth surfaces in reducing enamel solubility;
and serves to underscore the imperative of dental sealants
in a comprehensive program of prevention.
TOOTH SURFACE ATTACK
RATES IN PERMANENT
TEETH BY SURFACE
PREVALENCE OF SEALANTS
1988-1994 AND 1999-2002
PRINCIPLES UNDERLYING
SEALANT USE
• Prevention of dental caries is preferable to
treatment; sound, nondiseased teeth are to be
more highly valued than adequately restored
teeth.
• For equivalent outcomes, the least invasive
approach, using the simplest intervention for
managing dental caries is preferred.
• Minimizing the cost of preventing or controlling pit
and fissure caries is desirable.
• Strategies for sealant use may vary between
individual care and community-based programs.
SCIENTIFIC FACTS RELATED
TO SEALANT USE
• Sealants have been demonstrated to be a safe and
effective long-term method to prevent pit and
fissure caries.
• Pit and fissure caries attack begins in childhood
and continues through adolescence and into
adulthood.
• In addition to preventing carious lesions, sealants
can arrest caries progression.
• Effective sealant use requires meticulous
attention to detail in application technique,
particularly moisture control. Sealant retention
should be checked within one year of application.
RISK ASSESSMENT IN TREATMENT
PLANNING FOR SEALANTS
• Determination of the need for sealants begins with an
assessment of the individuals risk for dental caries, as well
as an assessment of the risk of the individual tooth.
• Factors to evaluate when considering individual teeth
include:
– individual’s risk for developing caries
– pit and fissure morphology
– caries pattern
– status of the proximal surface of the tooth in question.
• Not all permanent teeth have defined pits and fissures.
Teeth with well-coalesced groups do not require fissure
sealants.
• Children who grow and develop in communities with water
fluoridation have few pits and fissures with concomitantly
more well-coalesced grooves.
TREATMENT DECISION MAKING
• Studies suggest that the first and second permanent molars
are at the greatest risk for pit and fissure caries; premolars
are at significantly less risk.
• Primary teeth have an aprismatic layer of enamel and do not
etch in the same manner as permanent teeth, consequently
sealant retention is not as great on primary teeth.
Additionally, the grooves of primary teeth tend to be wellcoalesced in comparison to permanent teeth.
• In general, primary teeth are not sealed.
• The cost-benefit effectiveness is greatest in sealing first
and second permanent molars, and they should be given
preferential treatment to premolars in application of
sealants.
• Generally, insurance programs will not pay for sealants on
primary teeth or premolars.
• Indiscriminate sealing of teeth with low risk of caries
reduces the overall cost-effectiveness of sealants.
TREATMENT DECISION
MAKING
• Diagnosing dental caries on occlusal surface
surfaces can be challenging: Is it the lesion
cavitated or not.
• As previously discussed in caries diagnosis, unless
a tooth is clearly cavitated a sealant should be
placed. Cavitation of the enamel indicates that
the caries has penetrated past the DEJ.
• Cavitation is defined by cariologists as a lesion in
which the 0.5 mm rounded tip of a WHO probe
engages the lesion.
• If cavitated, a restoration should be placed, the
pulpal extent of which in into the dentin.
EFFICACY OF SEALANTS
• Sealants are effective as long as they remain
intact. With complete retention, sealed surfaces
are virtually impervious to decay.
• Therefore, the effectiveness of sealants in
preventing decay is measured by the retention of
the sealant.
• However, there is some evidence that caries
resistance is imparted by the presence of the
resin “tags” in the etched microporosities. If
true, the bulk of the sealant could be lost and if
the resin tags remain intact, caries prevention will
be effected.
• Glass ionomer sealants also may have imparted
caries resistance while in place.
VARIABLES AFFECTING
SEALANT RETENTION
• Position of the teeth in the mouth
– better sealant retention in mandibular versus maxillary
arch--???
• Skill of operator
– more skillful and experienced operators produce better
sealant retention
• Eruption status of the tooth
– the younger the child, the more difficult to maintain a
dry field due to the eruption status of the teeth;
partially erupted molars are difficult to isolate. As a
consequence typically delay sealant placement on first
and second molars until completely erupted.
– Patient Cooperation
– children who present problems with cooperation make
gaining and maintaining a dry field more difficult.
SEALANT RETENTION
• A compilation and summary of over 75
studies of sealant retention
indicates:
– 94% of sealants were intact after one
year
– 83% of sealants were intact two years
after placement.
– 67% were intact five years after
placement.
– 57% were intact after ten years.
UPDATING TECHINQUE:
MATERIALS
• There is a wide variety of sealant materials from which to
choose.
• Sealants are often classified by their method of
polymerization, either auto-polymerizing (chemically cured),
or visible light-cured sealants; they are also classified by
whether they are ‘filled’ resins, or ‘unfilled’ resins--though
increasingly the market is dominated by filled resins.
• Numerous studies have compared bond strengths and
retention rates between the two and found they offer
comparable results.
UPDATING TECHINQUE:
MATERIALS
• A further materials’ issue is the use of resin-based sealants
versus glass ionomer sealants . Glass ionomer sealants
release fluoride in addition to sealing the tooth.
• A traditional criticism of glass ionomer sealants is there is
some evidence that glass ionomer sealants are not retained
as well as resin-based sealants.
• However, a recent systematic review of the literature found
that the difference in retention between the two sealants
was small.
• Advocates of glass ionomer sealants argue that when
sealants are lost (whether in whole or part) the exposed
fissure is more resistant to caries due to the fluoride
release from the glass ionomer.
• Additionally, glass ionomer sealants are not as moisture
sensitive in placement as are resin-based sealants.
UPDATING TECHNIQUE:
CLEANING THE FISSURE
• Prior to acid etching the enamel, it is important to be sure
that the tooth surface and fissure areas are free of gross
plaque that might interfere with the etching process.
• Historically, it was recommended that this be done with a
prophylaxis cup or bristle brush and pumice.
• Recent studies have shown that cleaning the tooth with a
pumice prophylaxis does not significantly increase bond
strength.
• Current recommendation is to run an explorer through the
fissures and rinse forcefully with water; or, brush the
fissures thoroughly with a tooth brush to remove the gross
plaque.
• Complete debridement of plaque from the fissure is viewed
to be essentially impossible and not an imperative for
successful etching and sealant retention.
UPDATING TECHNIQUE:
ISOLATION
• Adequate isolation of the tooth is the most critical aspect
of the sealant application process.
• Salivary contamination of a tooth surface during or after
acid etching will have a deleterious effect on the ultimate
bond between the enamel and resin.
• Studies have shown that even a one second exposure of
etched enamel to saliva adversely affected bond strength
and sealant retention.
• Several studies have shown that rubber dam isolation and
cotton roll isolation provide comparable retention rates.
• However, it is obvious that rubber dam provides the best,
most controllable, isolation.
• When sealants are treatment planned for a tooth in a
quadrant where restorative therapy will also be
accomplished, the sealant should be placed under rubber
dam isolation in the context of the restorative treatment.
UPDATING TECHNIQUE:
ETCHING
• The most commonly used etchant is 37% orthophosphoric
acid; it is available as both a liquid and a gel.
• Etchant should be applied to all of the fissures and extend
2mm up the the cuspal inclines.
• Soft tissue exposure to the etchant is to be avoided.
• Historically, etchant times were 30-60 seconds; however,
recent studies have concluded that 15-20 seconds is
comparable and adequate.
• Rinse time is not important as previously thought (20
seconds). What is critical is that the etchant be completely
rinsed away.
• On thorough drying the enamel should present a chalky,
frosted appearance; if it does not, it must be re-etched..
DEMINERALIZATION PATTERNS
(SEM X 5,000)
Enamel prism
centers mainly
involved
DEMINERALIZATION PATTERNS
(SEM X 5,000)
Enamel prism
peripheries mainly
involved.
UPDATING TECHNIQUE:
APPLYING THE SEALANT
•
•
•
•
All susceptible pits and fissures should be sealed; this includes the
buccal pit of mandibular molars, and the lingual groove of maxillary
molars.
Recent studies have shown that using priming and bonding agents,
as an intermediate step, prior to placing the sealant, increases
sealant retention. Therefore it is recommended that a prime and
bond technique be used. With some marketed materials this is a
two step procedure. However, there are one-step prime and bond
products on the market today, and these are recommended as they
are more efficient. (3M/ESPE’s Prompt L-Pop and Caulk’s Prime and
Bond)
An additional advantage of using prime and bond before placing the
sealant, is that should the area become contaminated with saliva, it
only needs to be re-washed, not re-etched.
Care should be taken not to place excess sealant, which may affect
the child’s occlusion; and increase the potential for the sealant
bond being fractured.
PENETRATION OF MICROSCOPIC
SEALANT TAGS
OCCLUSAL SEALANT AFTER
REMOVAL OF ENAMEL BY
DEMINERALIZATION
INNER SURFACE OF SEALANT
AFTER REMOVAL OF ENAMEL BY
DEMINERALIZATION
POLYMERIZED SEALANT
TAGS (SEM X 3,000)
UPDATING TECHNIQUE:
POLYMERIZATION
• In one study it was found that the longer sealants were
allowed to remain on the tooth surface before being
polymerized, the more sealant penetrated the
microporosities, creating longer resin tags, which are the
critical dimension for micromechanical retention.
• Sealants in which polymerization was not effected for 20
seconds after application, had nearly three times longer
resin tags than those of sealants polymerized after 5-10
seconds. This is true when bonding composites to etched
enamel as well.
• When isolation can be adequately maintained, it appears to
be beneficial to wait for 20 seconds after sealant
application before applying the light activation.
• The above is applicable only if a prime and bond
technique is not employed.
UPDATING TECHNIQUE:
EVALUATING THE SEALANT
• All sealants should be visibly and tactually inspected for
complete coverage, and the absence of voids or air bubbles.
• Attempts should be made to dislodge the sealant with an
explorer.
• An evaluation of the occlusion should be conducted. Filled
resin sealants (which we utilize) in contrast to unfilled resin
sealants, are not easily abraded and can create occlusal
interferences. They should be adjusted with a rotary
instrument, if determined to be in hyperocclusion.
• The interproximals of the tooth should be evaluated as well
to ensure no sealant has flowed into the area inadvertently.