Dental Sealants

The caries process is multifactorial and, over time, can culminate in localized destruction of hard dental tissues by the weak acids produced by bacterial carbohydrate fermentation.¹ Microbiological shifts within the oral biofilm upset the balance of the tooth enamel remineralization/demineralization process; this balance is also affected by salivary flow and composition, fluoride exposure, consumption of dietary sugars, and preventive behaviors (e.g., brushing teeth).¹ Whether dental caries progresses, is halted, or reverses depends on a balance between protective and pathogenic factors.²

Anatomical grooves, or pits and fissures on occlusal surfaces of permanent molars can trap food particles and promote the presence of bacterial biofilm, increasing the risk of developing caries lesions. Effectively penetrating and sealing these surfaces with a dental material, e.g., pit-and-fissure sealants, can prevent lesions and is part of a comprehensive caries management approach.³ From the perspective of secondary prevention, sealants can inhibit the progression of non-cavitated caries lesions.⁴ The use of sealants to arrest or inhibit the progression of caries lesions is important to the clinician when determining the appropriate intervention for non-cavitated caries lesions.

Dental sealants are systems that can be applied to the occlusal surfaces of teeth to penetrate anatomic surface pits and fissures and form a physical barrier on the tooth surface.³  Sealant materials can be broken down into two main categories based on the type of reaction that takes place as they set in the mouth⁵. Glass ionomers undergo an acid-base reaction as they set, while composite resins set through a polymerization reaction that is usually initiated by a dental curing light.⁵ Resin-modified glass ionomers and polyacid-modified resins set by a combination of these two reactions, resulting in sealant products with differing characteristics that vary across a continuum from those of traditional glass ionomers to composite resins (Table).^{5, 6}

Table. Sealant Types (adapted from Albers⁶)

Glass Ionomer (acid-base reaction)	Resin-Modified Glass Ionomers	Polyacid-Modified Resins (compomer)	Composite Resin (polymerization)
-high acid-base bonding (only need a conditioner) -less shrinkage on setting -high fluoride release -low thermal expansion -low tensile strength -high susceptibility to desiccation -stiffer			-no acid-base bonding (requires resin-dentin bonding) -more shrinkage on setting -less fluoride release -less expansion (after water immersion) -higher tensile strength -low susceptibility to desiccation

Sealants are generally placed on the tooth in liquid form and then cured either chemically or with light activation.³ To prepare the tooth for bonding with the sealant system, the tooth surface is first treated with an acid etch to enhance wetting of the tooth with the liquid sealant and to optimize mechanical retention of the sealant.³  Sealants must also be of low enough viscosity to wet the tooth adequately and to flow readily into the pits and fissures on the tooth surface.³

Based on a systematic review, a 2016 guideline panel convened by the ADA CSA and the American Academy of Pediatric Dentistry (AAPD) came to the following evidence-based clinical recommendations for the use of pit-and-fissure sealants on the occlusal surfaces of primary and permanent molars in children and adolescents:^{7, 8}

• sealants are effective in preventing and arresting pit-and-fissure occlusal caries lesions of primary and permanent molars in children and adolescents compared to the non-use of sealants or use of fluoride varnishes; and
• sealants can minimize the progression of non-cavitated occlusal caries lesions (also referred to as initial lesions) of the tooth that received a sealant.

The report defined pit-and-fissure sealant materials as follows: 1) resin-based sealants; 2) glass ionomer cements or sealants; 3) polyacid-modified resin sealants; and 4) resin-modified glass ionomer sealants.³ There was insufficient evidence available at the time the guidelines were formulated to provide specific recommendations on the relative merits of one type of sealant material over the others.

Pit-and-fissure sealants are one of the most effective – yet underutilized – interventions for preventing caries, especially among children. New guidelines from the ADA Council on Scientific Affairs and the American Academy of Pediatric Dentistry confirm the effectiveness of sealants. Nonetheless, misperceptions still exist, and five of them are discussed below.

Misperception 1: The ADA has not stated a position on dental sealants.

For a number of years, the ADA Council on Scientific Affairs has recommended placing sealants on the primary and permanent molars of all children and adolescents to prevent caries. The Council also recommends dentists use pit-and-fissure sealants rather than fluoride varnish for the purposes of sealing the occlusal surfaces of molars.

Misperception 2: But isn’t fluoride varnish just as effective as dental sealants for preventing occlusal caries lesions?

No. Although fluoride varnish performs an important function in terms of preventing caries generally in at-risk patients,⁹ data from three studies^10-12 with nearly 2,000 total participants revealed those who received pit-and-fissure sealants on occlusal surfaces saw a 73% reduction in the risk of developing new caries lesions, compared to those participants who received only fluoride varnishes.

Misperception 3: Young patients could become exposed to concerning levels of bisphenol A (BPA) when receiving dental sealants.

The potential amount of BPA patients could be exposed to when receiving sealants is miniscule, and it’s less than the amount a person receives from breathing air or handling a receipt. There is no evidence of patients experiencing adverse effects caused by BPA in dental sealants (see “Bisphenol A and Dental Sealants” section, following).

Misperception 4: Sealants are not reimbursable under many dental plans.

Many dental plans will cover sealants (CDT code 1351) on children’s teeth. There are cost savings to patients from the prevention of non-cavitated caries lesions (which do not require treatment).

Misperception 5: Sealants should not be placed over initial caries (non-cavitated caries lesions) in the primary or permanent molars.

In addition to being effective for primary prevention of caries lesions, evidence indicates that sealants can also halt the progression of existing non-cavitated caries lesions in the teeth to which they are applied.

Dental materials used to treat and prevent caries, including dental sealants, may contribute exceedingly low levels of bisphenol A (BPA) for a few hours after placement.^13-15 In 2013, the ADA CSA adopted a statement on BPA and dental materials.

BPA might be found in dental composites and sealants for two reasons: as a by-product generated from degradation or as a trace contaminant from materials used in the manufacture of sealants and composites.  ADA research, confirmed by direct communications from dental material manufacturers, show that BPA is not used as a formula ingredient in dental materials.

The U.S. Department of Health and Human Services (HHS) provides scientific guidance on issues that affect the health of Americans, and the U.S. Food and Drug Administration (FDA) provides advice and recommendations on dental product safety. The National Toxicology Program of HHS reported that BPA in food and beverages accounts for the majority of daily human exposure.¹⁶ Based on this conclusion, in 2012, the FDA indicated that because there was sufficient uncertainty regarding human health concerns regarding BPA exposure, it would continue to provide for the use of BPA in dental materials, medical devices, and food packaging.¹⁷

Azarpazhooh and Main¹⁸ and a 2015 ADA Professional Product Review¹⁹ provide the following insights for dental providers to minimize BPA exposure following dental sealant placement:

• Be sure that your curing light is functioning properly
• Read and follow manufacturers’ instructions
• Fully adhere to manufacturers’ curing instructions
• Use a mild abrasive, or pumice on a cotton applicator or a prophylaxis cup to reduce the possibility of unpolymerized BPA remaining on the surface
• Wash the surface of the sealant for 30 seconds with an air-water syringe with suction to remove fluids and debris from a child’s mouth  
• Have older children and adults rinse with water after curing is complete

1. Selwitz RH, Ismail AI, Pitts NB. Dental caries. Lancet 2007;369(9555):51-9.
2. Featherstone JD. Caries prevention and reversal based on the caries balance. Pediatr Dent 2006;28(2):128-32; discussion 92-8.
3. Anusavice KJ, Shen C, Rawls RR. Phillips' Science of Dental Materials. Missouri, US: Elsevier/Saunders; 2013.
4. Splieth C, Forster M, Meyer G. Additional caries protection by sealing permanent first molars compared to fluoride varnish applications in children with low caries prevalence: 2-year results. Eur J Paediatr Dent 2001;3:133-37.
5. American Dental Association. ADA Professional Product Review: Academic Corner. 2008. Accessed August 1, 2016.
6. Albers HF. Resin Ionomers (Ch. 4). In: Tooth-Colored Restoratives: Principles and Techniques. Hamilton, ON: BC Decker Inc.; 2002.
7. Wright JT, Tampi MP, Graham L, et al. Sealants for preventing and arresting pit-and-fissure occlusal caries in primary and permanent molars: A systematic review of randomized controlled trials-a report of the American Dental Association and the American Academy of Pediatric Dentistry. J Am Dent Assoc 2016;147(8):631-45 e18.
8. Wright JT, Crall JJ, Fontana M, et al. Evidence-based clinical practice guideline for the use of pit-and-fissure sealants: A report of the American Dental Association and the American Academy of Pediatric Dentistry. J Am Dent Assoc 2016;147(8):672-82 e12.
9. Weyant RJ, Tracy SL, Anselmo TT, et al. Topical fluoride for caries prevention: executive summary of the updated clinical recommendations and supporting systematic review. J Am Dent Assoc 2013;144(11):1279-91.
10. Bravo M, Llodra JC, Baca P, Osorio E. Effectiveness of visible light fissure sealant (Delton) versus fluoride varnish (Duraphat): 24-month clinical trial. Community Dent Oral Epidemiol 1996;24(1):42-6.
11. Houpt M, Shey Z. The effectiveness of a fissure sealant after six years. Pediatr Dent 1983;5(2):104-6.
12. Liu BY, Lo EC, Chu CH, Lin HC. Randomized trial on fluorides and sealants for fissure caries prevention. J Dent Res 2012;91(8):753-8.
13. Fleisch AF, Sheffield PE, Chinn C, Edelstein BL, Landrigan PJ. Bisphenol A and related compounds in dental materials. Pediatrics 2010;126(4):760-8.
14. Joskow R, Barr DB, Barr JR, et al. Exposure to bisphenol A from bis-glycidyl dimethacrylate-based dental sealants. J Am Dent Assoc 2006;137(3):353-62.
15. Kingman A, Hyman J, Masten SA, et al. Bisphenol A and other compounds in human saliva and urine associated with the placement of composite restorations. J Am Dent Assoc 2012;143(12):1292-302.
16. Shelby MD. NTP-CERHR monograph on the potential human reproductive and developmental effects of bisphenol A. NTP CERHR Mon 2008(22):v, vii-ix, 1-64 passim.
17. U.S. Food and Drug Administration. Bisphenol A (BPA): Use in Food Contact Application. Accessed July 19, 2016.
18. Azarpazhooh A, Main PA. Pit and fissure sealants in the prevention of dental caries in children and adolescents: a systematic review. J Can Dent Assoc 2008;74(2):171-7.
19. American Dental Association. An ADA Laboratory Evaluation: Bisphenol A Released from Resin Based Dental Sealants (May 15, 2015). ADA Professional Product Review. Accessed July 19, 2016.

Professional Resources

• ADA Clinical Practice Guideline
• ADA Systematic Review: Sealants for Preventing and Arresting Pit-and-Fissure Occlusal Caries in Primary and Permanent Molars (2016)

ADA Professional Product Reviews (PPRs)

• Bisphenol A Released from Resin Based Sealants: Lab Report, Expert Panel, and Caries Corner (August 2016)
• An ADA Laboratory Evaluation: Bisphenol A Released from Resin-Based Dental Sealants (May 2015)
• Determination of Bisphenol A Released from Resin-Based Dental Composite Restoratives (July 2014)

Additional ADA Resources

• JADA: search articles related to sealants
• ADA Library

ADA Catalog

• Dental Sealants: Protecting Teeth, Preventing Decay (Item #W291 [English] or Item #W223 [Spanish])
• Sealants Quick Reference Card (Item #W276)
• Seal Out Decay (Item #W191)
• ADA Patient Smart

Patient Resources

• ADA MouthHealthy: Sealants
• JADA “For the Patient” page: Dental Sealants
  
  

Government Resources

• Centers for Disease Control and Prevention:

• Vital Signs: Dental Sealants Prevent Cavities (October 2016)
• Dental Sealants (July 2013)
• School-Based Dental Sealant Programs (October 2016)

• National Institute for Dental and Craniofacial Research: Seal Out Tooth Decay!

Cochrane Systematic Reviews

• Pit and fissure sealants versus fluoride varnishes for preventing dental decay in the permanent teeth of children and adolescents (January 2016) 
• Sealants for preventing decay in the permanent teeth (March 2013)

 Additional Resources

• Mayo Clinic: Cavities/Tooth Decay: Prevention
• MEDLINE Plus (U.S. National Library of Medicine): Patient Instructions - Dental sealants