Context <p>Pit and fissure caries remain a major challenge in preventive dentistry, necessitating the development of advanced bioactive sealants with enhanced properties.</p> Aim <p>To compare and evaluate the microleakage scores, resin-tag penetration, and remineralizing potential of nanosilver-reinforced (AgNP)&#xa0;sealant with three bioactive materials as sealants.</p> Methods and materials <p>68 extracted permanent molars were randomly divided into four groups (n = 17), Group I: Kids-e-Dental e-Pit &amp; Fissure Sealant, Group II: Shofu BeautiSealant, Group III: Pulpdent ACTIVA^™ Bioactive, and Group IV: Ivoclar Vivadent Cention^® N and occlusal fissures were sealed. After undergoing thermocycling, 14 teeth per group were sectioned bucco-lingually. One half of the section was analyzed for microleakage using stereomicroscope and the other was analyzed for resin-tag depth using SEM. Three teeth per group were subjected to EDX analysis at baseline and following 7-day pH-cycling. Statistical analysis was performed using chi-square test to compare microleakage scores, one-way ANOVA test for resin-tag depth and variation in mineral content from baseline to post-pH-cycling using paired sample t test.</p> Results <p>Microleakage scores were found to be statistically insignificant (p &gt; 0.05) across groups. A difference in resin-tag depth was statistically significant with group I exhibiting the highest mean resin-tag length and Group IV showing the lowest. All four groups showed variations in Ca, P, O, and F ion concentrations from baseline to post-pH-cycling, with Group I showing a statistically significant increase in fluoride ion concentration.</p> Conclusions <p>AgNP-reinforced sealant exhibits competitive performance relative to other bioactive sealants, with respect to resin-tag depth and fluoride ion exchange—both essential for sustained caries prevention.</p>