Effects of papain-based gel and air-abrasion enamel pretreatments on microleakage, sealant penetration, and shear bond strength of fissure sealant materials: an in vitro study.

INTRODUCTION: Establishing a durable seal between enamel and fissure sealant materials is critical for the long-term prevention of occlusal caries, particularly in anatomically complex pits and fissures. This in vitro study evaluated the effects of chemical pretreatment with a papain-based gel and mechanical pretreatment with air abrasion on the microleakage, sealant penetration, and shear bond strength of two pit and fissure sealant materials. METHODS: A total of 120 sound human premolars were randomly allocated according to sealant type, resin-based sealant (RBS) or resin-modified glass ionomer cement (RMGIC), and pretreatment protocol: no pretreatment, enzymatic papain-based gel, or air abrasion. Following sealant application and thermocycling, microleakage was evaluated by dye penetration under a stereomicroscope. Sealant penetration was measured in relation to fissure morphology using ImageJ software, and shear bond strength was evaluated using a universal testing machine. RESULTS: RBS showed significantly lower microleakage than RMGIC, indicating better sealing ability. Papain-based gel pretreatment significantly reduced microleakage in the RBS group without affecting sealant penetration or shear bond strength; however, no comparable improvement was observed in the RMGIC group. In contrast, air abrasion pretreatment did not produce a significant improvement in any of the evaluated outcomes. Fissure morphology significantly influenced sealant penetration, with wider fissure patterns demonstrating greater penetration. DISCUSSION: These findings indicate that fissure sealant performance is primarily influenced by material properties and fissure morphology, while the benefit of enamel pretreatment appears to be material-dependent.