Micro-tensile bond strength of two pit and fissure sealants to intact enamel

Background: Sealing dental pits and fissures with resin-based sealants effectively prevents occlusal dental caries. The effectiveness of resin-based pit and fissure sealants relies on maintaining a strong bond between the sealant and the enamel. Objective: This in-vitro study compared the micro-tensile bond strength (mu TBS) of a conventional resin-based sealant (Clinpro (TM)) and a hydrophilic resin-based sealant (Embrace (TM) WetBond (TM)) when applied to intact, aprismatic human enamel. Methods: Forty extracted permanent premolar and molar teeth were divided into two groups and paired by tightly approximating two buccal surfaces to create an artificial enamel groove (fissure). Fissure sealants (ClinproTM and Embrace (TM) WetBond (TM)) were applied to the artificial enamel 'grooves' in each group. The specimens were then cut into beams with a cross-sectional area of 1 mm(2) and tested for the micro-tensile bond strength (mu TBS). Fractured surfaces of samples were examined under a conventional microscope to identify the failure modes. Two specimens from each group were prepared and observed under a scanning electron microscope (SEM). Mann-Whitney U and Fischer-Freeman-Holton exact tests were used to test the statistical differences between the fissure sealants. Results: The mu TBS mean +/- SD for ClinproTM was 16.43 +/- 7.08, and 10.57 +/- 6.64 for EmbraceTM WetBondTM. There was a statistically significant difference in mu TBS between EmbraceTM WetBondTM and ClinproTM (p < 0.001). There was no association between fissure sealant and failure modes (p = 0.922). Conclusion: ClinproTM showed higher <mu>TBS to enamel than EmbraceTM WetBondTM. Further studies are needed to conclude the clinical effectiveness of these sealants.