Microleakage and penetration capability of various pit and fissure sealants upon different sealant application techniques

BACKGROUND: Sealant application that yields superior marginal adaptation and deeper fissure penetration potentially improves success in preventive and restorative dentistry. This study evaluated the amount of in-vitro microleakage and penetration capabilities of different pit-fissure sealants as the effect of different application techniques. MATERIAL AND METHODS: 160 freshly extracted human sound premolars, assigned as suitable for sealant application, selected and allocated randomly into 8 groups (n=20 teeth/group) and applied with different sealants including Embrace-Wetbond® (E), UltraSeal XT® (U), Clinpro™ (CL), Helioseal® (H), using either conventional (C) or induced application (I). The sealed teeth were thermocycling for 500 cycles between 5°C and 55°C with 30 seconds dwelling time. The tooth was coated with 2 layers of nail varnish, leaving 1 mm around the sealant margin, then immersed in 5% methylene blue solution for 24 hours. Subsequently, 2 pieces were segmented vertically in a buccolingual direction, yielding 4 surfaces/tooth for determination of microleakage and penetration proportion of sealant with polarized light microscopy (PLM) and image-J software. ANOVA and Bonferroni multiple comparisons were determined for significant differences (α=0.05). Sealant adaptability was detected using a scanning electron microscope (SEM). RESULTS: The highest microleakage was observed for EC, followed by CLC, HC, UC, CLI, HI, EI, and UI. The highest penetration was seen in UI, followed by HI, CLI, CLC, UC, HC, EI, and EC. ANOVA indicated significant differences in microleakage and penetration on the type of sealant and application method (p<0.05). SEM revealed that the I-application method significantly promoted less microleakage and better penetration than the C-application (p<0.05). CONCLUSIONS: Microleakage and penetration capabilities of sealant are greatly affected by the types of sealant and the method by which the sealant is applied. U-sealant exhibited less microleakage and better penetration capability than others. I-application reduced microleakage, promoting enhanced penetration and adaptation, is the recommended sealant application. Key words:Microleakage, penetration, dental sealant.