Pit-and-fissure sealants are thin, protective coatings applied to the chewing surfaces of the back teeth. This material, typically a liquid resin or glass ionomer, flows into the microscopic crevices of the tooth enamel. Once hardened, the sealant forms a smooth, plastic layer that acts as a shield over the molars and premolars, safeguarding the teeth from decay.
Preventing Decay: The Primary Goal
The primary purpose of applying pit-and-fissure sealants is to prevent occlusal caries, which is decay on the chewing surface. These surfaces contain deep grooves, or pits and fissures, that are highly prone to developing cavities because they trap bacteria and food particles. Even diligent brushing is often insufficient to clean the depth of these grooves, as toothbrush bristles cannot reach the very bottom. This leads to a persistent collection of plaque and acid-producing bacteria that erode the enamel. Sealants drastically reduce the risk of decay in these specific areas, where a majority of all cavities in younger populations originate.
The Mechanism of Protection
Sealants achieve their protective effect by physically blocking bacteria and their food source from accessing the tooth enamel. The liquid material is engineered to have a low viscosity, allowing it to penetrate and fill the deepest parts of the pits and fissures. This process completely seals off the susceptible grooves, creating an impervious barrier. Once the material hardens, the smooth, sealed surface prevents the entrapment of plaque and debris that would otherwise lead to acid production and decay. The sealant material bonds to the enamel primarily through a micromechanical lock, where the tooth surface is first treated with a mild acid solution (etch) to create microscopic pores for the sealant resin to flow into and securely interlock.
Target Teeth and Age Range
Pit-and-fissure sealants are applied to the chewing surfaces of the molars and premolars, which are the teeth most susceptible to occlusal decay. The timing of application is highly important for maximum benefit, typically coinciding with the eruption of the permanent teeth. The first permanent molars erupt around age six, and the second permanent molars emerge around age twelve, making these periods the ideal window for placement. The procedure is most commonly recommended for children and adolescents because their newly erupted teeth are the most vulnerable to decay. However, sealants can also benefit adults who have deep grooves without existing fillings or decay.
The Application Process and Lifespan
The application of pit-and-fissure sealants is a simple, non-invasive, and painless procedure that usually takes only a few minutes per tooth. The process begins with thoroughly cleaning the tooth surface, followed by the brief application of a mild acidic gel to etch the enamel, creating the necessary microscopic roughness for effective bonding. After the etch is rinsed off and the tooth is dried, the liquid sealant material is carefully painted onto the pits and fissures, and a specialized curing light is then shined on the material to rapidly harden the coating. The expected lifespan for a properly placed sealant ranges from five to ten years, providing a long period of protection. Regular dental check-ups are necessary to monitor the condition of the sealants, as they can wear down or chip over time; if damage or partial loss occurs, the material can be easily repaired or re-applied during a routine visit.