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 (μTBS) of a conventional resin-based sealant (Clinpro™) and a hydrophilic resin-based sealant (Embrace™ WetBond™) 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 (Clinpro™ and Embrace™ WetBond™) were applied to the artificial enamel 'grooves' in each group. The specimens were then cut into beams with a cross-sectional area of 1 mm² and tested for the micro-tensile bond strength (μTBS). 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 μTBS mean ± SD for Clinpro™ was 16.43 ± 7.08, and 10.57 ± 6.64 for Embrace™ WetBond™. There was a statistically significant difference in μTBS between Embrace™ WetBond™ and Clinpro™ (p < 0.001). There was no association between fissure sealant and failure modes (p = 0.922). Conclusion: Clinpro™ showed higher μTBS to enamel than Embrace™ WetBond™. Further studies are needed to conclude the clinical effectiveness of these sealants.