Pit and Fissure Sealants

Anatomy and Physiology

The morphology of the occlusal surface of the molars is extraordinarily variable. Occlusal fissures are deep invaginations of enamel that can be extremely diverse in shape and have been described as broad or narrow funnels, constricted hourglasses, and multiple invaginations with inverted Y-shaped divisions and irregularly shaped. Due to this morphological diversity, categorizing a tooth as having a single, definitive type of fissure is often not possible.[2] Fissure types include:

• V type: Wide at the top and gradually narrowing towards the bottom; shallow and wide; tends to be self-cleaning.
• U-type: Shallow and wide; tends to be self-cleaning.
• I-type: Extremely narrow slit; deep, narrow, and constricted, resembling a bottleneck; more caries susceptible.
• IK- type: A narrow slit associated with a larger shape at the bottom; may require invasive technique and are very susceptible to caries.

Indications

Pit and fissure sealants can serve as either a primary preventive measure for individuals at high risk for caries or as a secondary preventive measure to arrest early carious lesions. Indications include:

• Deep pits and fissures of deciduous teeth in children at elevated caries risk [5]
• Pits and fissures of permanent teeth in children and adolescents at increased risk [6][7]
• Permanent teeth in at-risk adults [6][7]
• Noncavitated carious lesions in pits and fissures across all age groups [8]
• Patients with medical or physical disabilities where dental disease could jeopardize systemic health or necessitate complex treatments [9]

The use of sealants should be guided by individual caries risk, not just eruption status. Although no diagnostic tool perfectly predicts caries development, a history of caries remains the most reliable indicator of risk for caries development. Resin-based sealants are generally more effective than glass ionomer cements due to superior sealing ability. Nevertheless, glass ionomer materials still have a role, especially in situations where rubber dam isolation is not possible. Even when dentin is involved, sealing can be effective if a tight bond is achieved. In primary teeth, sealants may perform comparably well as more invasive procedures.

Dental sealants are recommended for both permanent and primary teeth. In permanent molars, resin sealants have been shown to reduce caries incidence for up to 4 years compared to no treatment.[10] The evidence on sealing cavitated caries is mixed; while some studies report success in arresting micro-cavitated lesions, others show limited efficacy beyond noncavitated stages.[11][12]

Sealants can be applied to occlusal surfaces, as well as to smooth and proximal surfaces. Research supports their use in preventing both occlusal surface caries and arresting noncavitated and microcavitated lesions on proximal surfaces.[11][13][14] Sealants may be applied to both fully and partially erupted molars. However, retention is lower in the latter due to moisture control challenges, making glass ionomer a preferable choice in such cases. They are also effective on fluorotic teeth, with resin sealants showing significantly better retention than glass ionomer sealants after 1 year.[11]

Contraindications

Dental professionals should determine the need for a pit and fissure sealant based on the patient’s individual risk rather than age or the time since tooth eruption.[15] For patients without risk factors or those at low risk for developing carious lesions, applying a sealant may not be necessary at that time. Regular monitoring remains essential for all children to identify any changes in cariogenic risk factors, as well as clinical or radiographic signs of dental decay.[9] Ongoing assessment ensures timely intervention when risk levels increase, allowing preventive measures to be implemented effectively and maintaining optimal oral health outcomes.

Equipment

Sealant Materials

Dental sealants can be categorized into resin-based, glass ionomer, and hybrid materials, each with specific properties that influence their clinical application, longevity, and effectiveness in caries prevention.

Resin-based sealants

Resin-based sealants are considered the first-line treatment due to their superior retention and mechanical properties. They typically consist of an organic resin matrix, eg, Bis-GMA, UDMA, or TEGDMA, and may include fillers, fluoride-releasing agents, or photo-initiators to enhance anticariogenic properties and physical performance.[11]

Based on their polymerization mechanism, resin sealants are available in either self-curing (auto-curing) or light-curing formulations. Self-cure sealants harden through a chemical reaction initiated by tertiary amines and benzoyl peroxide, whereas light-cure sealants utilize visible light to activate photo-initiators, providing a longer working time and more controlled placement.[11]

Some resin sealants incorporate fluoride-releasing components, eg, sodium fluoride or fluoride-containing glass fillers, to provide an additional layer of caries protection. Resin sealants can also be categorized into 2 types: filled and unfilled. Filled sealants are more wear-resistant but tend to be more viscous, which can limit their ability to flow effectively into narrow or deep fissures.[16] Another distinction lies in hydrophobic versus hydrophilic formulations. Traditional hydrophobic sealants require strict moisture control, whereas newer hydrophilic sealants incorporate acrylate monomers to improve their use under suboptimal conditions.[17]

Glass ionomer sealants

Glass ionomer sealants provide a valuable alternative when resin placement is contraindicated, eg, in partially erupted molars or areas with poor isolation. These materials release fluoride over time, supporting long-term caries prevention.[18][19] Conventional glass ionomers set through an acid-base reaction between fluoroaluminosilicate glass and polyacrylic acid, while resin-modified glass ionomers incorporate monomers, eg, 2-hydroxyethyl methacrylate (HEMA) or urethane dimethacrylate (UDMA), undergoing both acid-base and light-initiated polymerization to improve physical properties.[11]

Hybrid sealants 

Hybrid sealants represent a newer category and include materials such as compomers (polyacid-modified composite resins) and giomers. Compomers combine elements of both composites and glass ionomers, including reactive fillers and photo-initiators, while giomers contain pre-reacted glass ionomer (PRG) particles within a resin matrix.[20] Although these materials aim to merge the benefits of both parent systems, they are not yet widely used in clinical practice.

Sealant color

An additional classification criterion involves sealant color. Sealants may be clear, white, or pink to allow for visualization during placement, but they later change to a white color. Clear types improve visualization of the underlying enamel, which can be beneficial for monitoring early lesions. However, their translucency may make clinical detection during follow-up examinations more difficult.[21] 

Additional Equipment

Additional equipment necessary for sealant placement typically includes:

• Air/water syringe
• Mouth mirror
• Explorer
• Excavator tip
• Squares of 2 x 2 gauze 
• Cotton rolls
• Cotton pellets
• Forceps/cotton pliers
• Articulating paper
• Curing light
• Handpiece
• Dappen dish with pumice

Preparation

The need and method for surface cleansing of pits and fissures before placing a sealant vary among operators. Some have suggested using pumice or air-polishing instruments to obtain an optimal acid-etch pattern of the enamel. At the same time, others consider acid etching alone as sufficient for surface cleaning.[9]

Technique or Treatment

Isolation of the Tooth

Moisture control represents the most critical factor in the successful placement of pit and fissure sealants, making rubber dam isolation the preferred method. Inadequate isolation allows fluids to penetrate the enamel porosities created during etching, blocking resin tags and reducing material retention.

Absolute isolation may not always be possible or practical, particularly in newly erupted teeth, where local anesthesia would be required to place the clamp. In such situations, a dry field can be maintained through the use of cotton rolls, isolation shields, and strategic positioning of the evacuation tip. When optimal isolation cannot be achieved, the application of glass ionomer can serve as a temporary protective measure until definitive sealant placement becomes feasible.

Acid Etching

The most frequently used agent for acid etching is 37% orthophosphoric acid. The gel can be applied directly with special application tips or with a small disposable brush. Application should cover all susceptible pits and fissures, extending up to the cuspal inclines. The following steps are typical techniques used for etching:

• Etch permanent molars for 15 seconds and primary teeth for 15 to 30 seconds. Teeth affected by dental fluorosis require additional etching time. When glass ionomer cement is used, etching is not required; instead, apply a surface conditioner such as polyacrylic acid.

• Rinse thoroughly with an air-water spray.

• Dry the tooth with uncontaminated compressed air until a frosty white opaque appearance becomes visible.

• Replace cotton rolls if cotton roll isolation has been used.

• Re-etch the surface if contamination occurs.[22]

Sealant Placement and Curing

Many sealant kits have their own dispensers and instructions that must be followed, including:

• Apply sealant and allow it to flow into pits and fissures
• In mandibular teeth, apply the sealant from the distal aspect, allowing it to flow mesially.
• In maxillary teeth, apply the sealant from the mesial aspect, allowing it to flow distally.
• Use a fine brush and carry sealant material up to the cuspal inclines.
• Avoid air bubbles.

Light Cured Sealant

The tip of the curing light should be positioned 3 to 5 mm from the sealant surface and applied for 10 to 20 seconds to ensure proper polymerization. Maintaining the correct distance and curing time enhances the strength and longevity of the material.

Once the sealant has set, wipe the surface with a wet cotton pellet to remove the air-inhibited layer of non-polymerized resin. Omitting this step may leave residual material that produces an unpleasant taste in the patient’s mouth, reducing comfort and satisfaction with the procedure.

Evaluation of the Sealant and Occlusion of Sealed Tooth Surfaces

Following placement of the sealant and light curing, clinicians should assess the integrity of the seal. The retention of sealants is visually and tactically evaluated using a probe. Careful inspection helps determine whether the sealant remains intact or requires reapplication due to partial loss or complete dislodgment.[4]

Additionally, the occlusion should be checked with articulating paper, and any interference should be adjusted using a round finishing bur. Annual recalls should be conducted, as 5% to 10% of sealants typically require repair or replacement each year. Consistent follow-up ensures long-term effectiveness and prevents complications related to caries development. 

Follow-up

Sealed surfaces should be regularly monitored clinically. Bitewing radiographs are recommended for radiographic assessment, which should be performed as often as the risk status indicates. However, the risk status may change over time; therefore, other susceptible sites, eg, proximal surfaces, should also be monitored. Defective sealants must be reapplied to maintain marginal integrity.[9]

Complications

An unsuccessful pit and fissure sealant placement may be due to any of the following:

• Contamination may result from either saliva or calcium phosphate products
• Inadequate surface preparation
• Incomplete or slow photopolymerization
• Air entrapment
• Overextension of the material beyond the conditioned tooth surface

Clinical Significance

About one-fourth of children and more than one-half of adolescents experience caries in their permanent teeth.[23] The occlusal surfaces of posterior teeth carry the highest risk due to pits and fissures with complex morphologies that provide an ideal environment for bacterial accumulation and caries progression.

Extensive evidence supports sealants as an effective intervention for both preventing caries and arresting noncavitated lesions. One study in children demonstrated a 37% reduction in caries risk with pit and fissure sealants compared to a control group. Another study found that, over a 3-year period, first permanent molars treated with sealants showed a 44% lower risk of developing caries compared to untreated teeth.[3] Caries risk assessment remains essential in guiding clinical decisions, and each patient’s risk status should be reassessed periodically to optimize preventive care.

Enhancing Healthcare Team Outcomes

Pit and fissure sealants represent an evidence-based strategy for preventing dental caries, particularly in children and individuals with limited access to care. The effectiveness of this intervention relies not only on proper material selection and clinical technique but also on early identification of at-risk patients and ongoing maintenance. High-risk populations benefit most when multiple healthcare professionals contribute to prevention efforts through coordinated roles and responsibilities.

Dentists and hygienists provide technical expertise in isolation, application, and follow-up, while assistants support workflow efficiency and patient care. Pediatricians and nurses identify candidates during routine wellness visits, ensuring timely referrals to dental professionals. Pharmacists reinforce patient education, emphasize the importance of preventive oral care, and guide product choices. Public health professionals extend services to underserved communities through school-based and outreach programs, supported by trained hygienists and assistants. Interprofessional communication, respect for patient autonomy, and evidence-based decision-making strengthen care coordination, improving sealant retention and reducing caries incidence. This collaborative, patient-centered approach enhances outcomes, patient safety, and team performance across diverse healthcare settings.