Abstract
BACKGROUND: Dental caries is a major global health issue, leading to tooth loss, infections, and even systemic complications. Modern dentistry favours minimally invasive caries removal, but its impact on the bond between composite and caries-affected dentin requires further study. The present in vitro analysis evaluated the microtensile bond strength (μTBS) of composite bonded to human dentin impacted by caries, after three caries removal methods: SmartPrep bur, chemo-mechanical removal, and air abrasion. The null hypothesis posited no significant difference in bond strength among the techniques. MATERIAL AND METHODS: Twenty-one extracted human molars with caries, but no pulpal involvement, were randomly allocated into three groups. Caries removal was performed using: 1) SmartPrep bur, 2) chemo-mechanical method using Papacarie® gel (Formula & Acao, Sao Paulo, Brazil) 3) air abrasion (AquaCare air-abrasion (Velopex, London, UK). Following caries removal, a two-step etch-and-rinse adhesive and composite restoration were placed. The test specimens from each group underwent microtensile bond strength testing utilizing a Universal Testing Machine, data were statistically analysed using one-way ANOVA and further examined with Tukey's post hoc test (p<0.05). RESULTS: Analysis revealed that SmartPrep bur demonstrated superior microtensile bond strength (33.31 ± 10.23 MPa), followed by chemo-mechanical removal (22.86 ± 11.61 MPa). Air abrasion yielded the lowest mean bond strength values (15.74 ± 2.99 MPa). The SmartPrep bur and air abrasion groups showed statistically significant differences (p = 0.012). CONCLUSIONS: This study demonstrated that the caries removal technique significantly influences the bond strength of composite to caries-affected dentin. The SmartPrep bur achieved superior microtensile bond strength, suggesting potential clinical benefits. These results emphasize the importance of technique selection for achieving optimal restorative outcomes. Key words:Caries, Dentin, adhesion, tooth.