Comparison of microleakage of different methods of repairing fissure sealants

Fissure sealants are applied in order to obliterate the fissures and isolated them from surrounding decay-causing environment. If these materials are lost، they should be repaired to provide protection from tooth caries. The aim of this study was to evaluate microleakage of repaired fissure sealants after using preparation methods such as prophylaxis، enameloplasty، air abrasion، application of bonding agents and beveling of fissures. In this in vitro experimental study، fifty caries-free third molars were used. After cleaning by prophylaxis and acid etching، the fissure sealant (Fissurit FX) was placed on the teeth while a periodontal probe was placed on one half of the occlusal surface to create a break point sealant before curing، which was removed after light-curing. The sealant of one half of the surface was removed and the teeth were randomly placed in one of the five groups: 1) prophylaxis and etching (control); 2) enameloplasty with a round carbide bur and etching; 3) air abrasion and etching; 4) etching and application of the bonding agent; 5) beveling the margins of the buccal aspect of the occlusal fissure and etching. After thermocycling and sealing the teeth، they were immersed in 1% methylene blue for 48 hours. Then the teeth were sectioned longitudinally in a mesiodistal direction. The sections was examined under a stereomicroscope for microleakage. Data were analyzed with Kruskal-Wallis test. The highest and lowest rates of microleakage were seen in group 2 (enameloplasty) and group 5 (bevel of the buccal fissure)، respectively. Statistical analysis with Kruskal-Wallis test showed no significant differences between the groups (p value = 0. 19). This study did not demonstrate any one single method of repair to be superior to the control method for reapplication of the sealant. It seems that persistence of each of these methods depends on the results of future studies، especially clinical studies.