An In Vitro Evaluation of the Effects of Different Pre-Treatment Protocols on Fissure Sealant Microleakage

Background: Optimal marginal sealing ability is highly dependent on pre-treatment protocols, use of adhesives, and sealant materials. Studies have been conducted worldwide for enamel surface preparation and placement methods prior to fissure sealant application, but the results were mixed.

Objectives: To evaluate and compare in vitro, the effects of applying different enamel pre-treatments with conventional acid-etch, etch-and-rinse adhesives, and self-etch adhesives on microleakage around fissure sealant margins in primary and permanent molar teeth.

Materials and Methods: 30 extracted human permanent third molars and 30 extracted primary second molars were randomly assigned into three groups of ten teeth each. Clinpro, resin-based fissure sealant was applied after undergoing either one of these pre-treatment protocols; 1) Phosphoric acid etching; 2) Acid etching + Prime & Bond NT (etch-and-rinse adhesives) and 3) Single Bond Universal (self-etch adhesives). The teeth were stored inside a distilled water for 30 days, followed by thermocycling and then, immersed for 24 hours in 0.5% basic fuchsin solution. A total of 180 surfaces were identified and examined under a stereomicroscope for microleakage scoring by two calibrated observers. Statistical analysis was done using SPSS version 23.0. Kruskal-Wallis test was used for comparison between three pre-treatment protocols.

Results: There was a significant difference (p < 0.05) among the three groups in both permanent and primary groups. In permanent teeth, acid etching technique showed the highest group of (score 0) no leakage (96.7%), followed by self-etch adhesive and etch-and-rinse adhesive at (76.7%) and (46.7%) respectively. Primary teeth also showed that acid etching technique had the highest group of (score 0) no leakage (93.3%), followed by the self-etch adhesive (73.3%), and etch-and-rinse adhesive (63.3%).

Conclusions: Fissure sealant applied with conventional acid etching technique showed the least microleakage, followed by self-etch adhesive technique, and etch-and-rinse adhesive technique in both permanent and primary teeth.