An in vitro study of microleakage of pit and fissure sealants in the presence of occlusal forces

The purpose of this study was to evaluate the effect of load on microleakage of pit and fissure sealants. In the first phase of the study load of maximal force (F = 880 N) on central and peripheral enamel was applied. Three groups of ten specimens were tested for microleakage. Group A no application of load, Group B application of load on the central pit of the tooth, and Group application of load on the peripheral enamel 2.5 mm away from the margin of the tooth, at the level of dentinoenamel junction. The results of that study showed significant increase of microleakage on the peripheral sealed enamel, as well as enamel microcracks. So, in the phase II sixty wisdom teeth were sealed with Ultra seal XT plus and load of different magnitude was applied on the peripheral enamel. The specimens were thermocycled for 500 cycles at 5 degrees C and 55 degrees C with a dwell of 30 seconds at each temperature prior to load application. Six groups of ten specimens were tested for microleakage under load. The force was applied at the peripheral enamel, 2.5 mm away from the margin of the tooth, at the level of dentin-enamel junction in cross-section view. Group A: F = 0 N; Group B: F = 300 N; Group C: F = 400 N; Group D: F = 500 N; Group E: F = 600 N; Group F: F = 700 N. Microleakage was scored as distance of dye penetration with 0 = no microleakage and 3 = microleakage to underlying fissure. A linear regression statistics was used with R-squared of 0.31. The groups with load applied (B, C, D, E, F) showed statistically significant results (p < 0.05) compared with group A (F = 0 N). Both, the magnitude of the force and tooth morphology may influence the degree of microleakage observed after the placement of sealants.