Pit & fissure sealants (1)

Editor's Notes

• #9: Over 85% of children (5-17 years old) in US have caries in the pits and fissures - these children are mostly from low-income families and other vulnerable populations
• #11: Initial studies of community water fluoridation demonstrated that reductions in childhood dental caries attributable to fluoridation were approximately 50%--60% ( 94--97 ). More recent estimates are lower --- 18%--40% ( 98,99 ). This decrease in attributable benefit is likely caused by the increasing use of fluoride from other sources, with the widespread use of fluoride toothpaste probably the most important. The diffusion or "halo" effect of beverages and food processed in fluoridated areas but consumed in nonfluoridated areas also indirectly spreads some benefit of fluoridated water to nonfluoridated communities. This effect lessens the differences in caries experience among communities ( 100 ). Studies of the effects of school water fluoridation in the United States reported that this practice reduced caries among schoolchildren by approximately 40% ( 118--122 ). A more recent study indicated that this effect might no longer be as pronounced ( 123 ). Studies of 2--3 years duration have reported that fluoride toothpaste reduces caries experience among children by a median of 15%--30% ( 139--148 ). This reduction is modest compared with the effect of water fluoridation, but water fluoridation studies usually measured lifetime --- rather than a few years' --- exposure. Regular lifetime use of fluoride toothpaste likely provides ongoing benefits that might approach those of fluoridated water. Combined use of fluoride toothpaste and fluoridated water offers protection above either used alone ( 99,149,150 ). Studies indicating that fluoride mouthrinse reduces caries experience among schoolchildren date mostly from the 1970s and early 1980s ( 184--191 ). In one review, the average caries reduction in nonfluoridated communities attributable to fluoride mouthrinse was 31% ( 191 ). Two studies reported benefits of fluoride mouthrinse approximately 2.5 and 7 years after completion of school-based mouthrinsing programs ( 192,193 ), but a more recent study did not find such benefits 4 years after completion of a mouthrinsing program ( 194 ). The National Preventive Dentistry Demonstration Program (NPDDP), a large project conducted in 10 U.S. cities during 1976--1981 to compare the cost and effectiveness of combinations of caries-prevention procedures, reported that fluoride mouthrinse had little effect among schoolchildren, either among first-grade students with high and low caries experience ( 195 ) or among all second- and fifth-grade students ( 196 ). NPDDP documented only a limited reduction in dental caries attributable to fluoride mouthrinse, especially when children were also exposed to fluoridated water. The evidence for using fluoride supplements to mitigate dental caries is mixed. Use of fluoride supplements by pregnant women does not benefit their offspring ( 198 ). Several studies have reported that fluoride supplements taken by infants and children before their teeth erupt reduce the prevalence and severity of caries in teeth ( 98,199--207 ), but several other studies have not ( 19,208--212 ). Among children aged 6--16 years, fluoride supplements taken after teeth erupt reduce caries experience ( 213--215 ). Fluoride supplements might be beneficial among adults who have limitations with toothbrushing, but this use requires further study. Clinical trials conducted during 1940--1970 demonstrated that professionally applied fluorides effectively reduce caries experience in children ( 233 ). In more recent studies, semiannual treatments reportedly caused an average decrease of 26% in caries experience in the permanent teeth of children residing in nonfluoridated areas ( 191,234--236 ). The application time for the treatments was 4 minutes. In clinical practice, applying fluoride gel for 1 minute rather than 4 minutes is common, but the efficacy of this shorter application time has not been tested in human clinical trials. In addition, the optimal schedule for repeated application of fluoride gel has not been adequately studied to support definitive guidelines, and studies that have examined the efficacy of various gel application schedules in preventing and controlling dental caries have reported mixed results. On the basis of the available evidence, the usual recommended frequency is semiannual ( 151,237,238 ). Studies conducted in Canada ( 242 ) and Europe ( 243--246 ) have reported that fluoride varnish is efficacious in preventing dental caries in children. Applied semiannually, this modality is as effective as professionally applied fluoride gel ( 247 ). Some researchers advocate application of fluoride varnish as many as four times per year to achieve maximum effect, but the evidence of benefits from more than two applications per year remains inconclusive ( 240,246,248 ). Other studies have reported that three applications in 1 week, once per year, might be more effective than the more conventional semiannual regimen ( 249,250 ). Combinations of Fluoride Modalities Studies comparing various combinations of fluoride modalities have generally reported that their effectiveness in preventing dental caries is partially additive. That is, the percent reduction in the prevalence or severity of dental caries from a combination of modalities is higher than the percent reduction from each modality, but less than the sum of the percent reduction of the modalities combined. Attempts to use a formula to apply sequentially the percent reduction of an additional modality to the estimated remaining caries increment have overestimated the effect ( 151,253 ). For example, if the first modality reduces caries by 40% and the second modality reduces caries by 30%, then the calculation that caries will be reduced by a total of 58% (i.e., 40% plus 18% [30% of the 60% decay remaining after the first modality]) will likely be an overestimate.
• #13: Liquids – soft drinks, fruit drinks, cocoa, sugar and honey in beverages, nondairy creamers, ice cream, sherbet, jello, flavored yogurt, pudding, custard, popsicles. Solid and Sticky – cake, cupcakes, donuts, sweet rolls, pastry, canned fruit in syrup, bananas, cookies, chocolate candy, caramel, toffee, jelly beans, other chewy candy, chewing gum, dried fruit, marshmallows, jelly, jam Slowly Dissolving – hard candies, breath mints, antacid tablets, cough drops
• #14: “ Occlusal Sealing” – 1965 Mixing methyl-2-cyanoacrylate with poly(methyl methacrylate) and inorganic powder then placed in pits and fissures. Polymerized on exposure to moisture
• #18: Debris and/or saliva contamination – use a hydrophilic primer to dry the tooth surface and thoroughly clean the tooth Air inclusion during manipulation – surface voids which can discolor and retain plaque Manipulating self-cured sealants late in the setting reaction can disrupt polymerization and induce bond failure
• #44: (Bis-GMA) Bisphenol A-glycidyl methacrylate resins 3 parts composite resin mixed with a diluent (methyl methacrylate or triethylene glycol dimethacrylate) – to obtain a low-viscosity sealant Sealants with fluoride – Glass ionomer Anticariogenic- high fluoride content Since viscous it is difficult to gain penetration to the depth of the fissure. This lack of penetration makes it difficult to obtain mechanical retention to the enamel surface to the same degree as Bis-GMA resins
• #45: Filler makes sealant more wear resistant and more visible upon clinical inspection Filler – fumed silica or silanated inorganic glasses Unfilled sealants are clear making detection difficult. Less resistant to wear over the long term. Best used when high spots can’t be adjusted i.e. school based setting.
• #55: The surface of the substrate be clean The adhesive wet the substrate well, have a low contact angle, and spread onto the surface Adaptation to the substrate produce intimate approximation of the materials without entrapped air or other intervening materials The interface include the sufficient physical, chemical, and/or mechanical strength to resist intraoral forces of debonding The adhesive be well cured under the conditions recommended for use.
• #79: Avoid rubbing the etched surface during etching and drying because the roughness developed can easily be destraoyed. The etched area should extend beyond the anticipated area for sealant application to secure optimum bonding along the margin aad reduce the potential for early leakage.
• #80: Inadequate rinsing permits phosphate salts to remain on the surface as a contaminant, interfering with bond formation
• #83: Bond agent will improve retention especially when there appears to be minor moisture or salivary contamination.