Comparative evaluation of Penetration Depth, Marginal Adaptation and Microleakage of Conventional, Hydrophilic and Bioactive Pit and Fissure sealants in extracted third molars – an in-vitro study

Abstract Introduction Dental caries predominantly affects the occlusal pits and fissures of posterior teeth due to their plaque-retentive anatomy. Pit and fissure sealants provide a protective barrier; however, their effectiveness depends on penetration, marginal adaptation, and microleakage. Hydrophilic and bioactive sealants have been developed to overcome limitations of conventional resin-based materials. Objectives To compare the penetration depth, marginal adaptation, and microleakage of conventional, hydrophilic, and bioactive pit and fissure sealants. Methods This in vitro study included 81 sound extracted third molars, randomly allocated to three groups (n = 27): Conseal F (conventional), UltraSeal XT Hydro (hydrophilic), and BioCoat (bioactive). Following sealant placement and thermocycling (250 cycles, 5–55°C), penetration depth, marginal adaptation, and microleakage (n = 9/group) were assessed using stereomicroscopy, scanning electron microscopy, and confocal laser scanning microscopy, respectively. Data were analysed using ANOVA, Tukey’s post hoc, and Chi-square tests. Results Conseal F demonstrated the highest complete penetration (33.3%; p = 0.01). BioCoat showed the greatest mean penetration depth (583.33 ± 125 µm; p < 0.03), superior marginal adaptation (66.7% smooth margins; p < 0.001), and least microleakage (55.6% with no dye penetration; p < 0.001). UltraSeal XT Hydro showed the highest microleakage (p = 0.007). Conclusion BioCoat demonstrated superior marginal adaptation and sealing ability, suggesting potential for enhanced fissure protection. Further long-term clinical studies are warranted. Clinical Significance BioCoat, with its bioactive properties and favourable sealing characteristics, may be a preferable option for preventive occlusal caries management by limiting microleakage at the sealant tooth interface. Its potential to preserve tooth structure and support minimally invasive care highlights a promising biologically orientated approach to caries-preventive sealants.