Dental sealants are thin, plastic coatings painted onto the chewing surfaces of the back teeth to prevent decay. Molars and premolars contain natural pits and fissures that are often too narrow for toothbrush bristles to clean effectively, making them susceptible to trapping food particles and bacteria. By filling these deep grooves, the liquid coating creates a smooth, protective shield over the enamel. The application process is a simple, non-invasive procedure that provides a physical barrier against cavity-causing agents.
Preparing the Tooth for Placement
Meticulous preparation of the tooth surface is essential before the sealant material is applied. The first step involves thoroughly cleaning the pits and fissures of the target tooth to remove any plaque or debris that could compromise the bond. This cleaning is typically done using a mild abrasive material like pumice or a specialized air-polishing device.
After cleaning, the tooth must be isolated and kept completely dry, as moisture contamination is the primary cause of sealant failure. Dental professionals achieve this isolation using absorbent materials like cotton rolls, dry field pads, or a rubber dam. Maintaining a dry field is necessary because saliva prevents the sealant material from adhering to the enamel surface.
Once the tooth is isolated and dry, a mild acid etchant, usually a phosphoric acid gel, is applied to the chewing surface for 15 to 20 seconds. This gel microscopically roughens the enamel surface, creating tiny pores and channels. This etching allows the liquid sealant to flow into and mechanically lock onto the tooth, creating a strong, durable bond with the natural tooth structure.
The Sealant Application Process
The acid gel is thoroughly rinsed off the tooth with water for 10 to 15 seconds, and the surface is dried again with air. A properly etched tooth will exhibit a distinct, dull, chalky-white appearance. If the tooth surface becomes contaminated with saliva at this stage, the etching process must be repeated to ensure the bond is not compromised.
Next, the liquid sealant material, often a resin-based compound, is carefully painted onto the prepared chewing surface using a small brush or a syringe. It is applied in a thin layer, allowing the low-viscosity material to flow deeply into the narrowest pits and fissures of the tooth. This precise placement ensures that all vulnerable grooves are sealed off from the oral environment.
A specialized curing light, which emits blue light, is shone directly onto the sealant material for 20 to 30 seconds. This light initiates polymerization, which rapidly hardens the liquid resin, transforming it into a solid, durable plastic barrier. The entire process of applying and curing the material is quick, often taking only a few minutes per tooth.
Post-Application Care and Longevity
Immediately after the sealant has hardened, the dental professional checks the patient’s bite to ensure the new material does not interfere with the natural alignment of the teeth. This check is performed using articulating paper, which leaves a colored mark on any high spots. If necessary, any excess sealant material is gently adjusted or polished down until the bite feels smooth and comfortable.
Patients can typically eat and drink right away, but they should be mindful of the newly placed material for the first 24 hours. Avoiding exceptionally hard or sticky foods, such as ice, hard candy, or caramel, is recommended because these items can potentially chip or dislodge the sealant before it has fully set. Maintaining regular brushing and flossing routines is important, as sealants only protect the sealed surface.
With proper oral hygiene and regular professional monitoring, dental sealants can provide protection for several years, often lasting between five and ten years before needing repair or reapplication. Regular dental check-ups allow the dentist to examine the integrity of the sealant, checking for wear or chipping. Prompt repair of a partially lost sealant is necessary to maintain the protective barrier against decay.
Who Should Get Sealants?
While anyone with healthy, decay-free molars and premolars can benefit from dental sealants, they are most commonly recommended for children and teenagers. This is because their permanent molars, which are the teeth most frequently sealed, typically erupt around ages six and twelve. Applying the sealant shortly after eruption protects the enamel during its most vulnerable stage.
Sealants are effective in children; data suggests that school-age children without sealants have significantly more cavities in their first molars than those who have them. The deep grooves in newly erupted teeth are a prime target for decay, and the sealant provides a defense against this early damage.
Adults can also receive sealants, especially if they have deep pits and fissures in their back teeth that are difficult to clean and have no existing decay or fillings. High-risk adult patients, such as those with a history of frequent decay, may also be candidates. Sealants are a preventive measure, placed only on teeth that are currently healthy and free of cavities.