Relationship between microtensile bond strength and nanoleakage at the composite–dentin interface

Abstract Objectives This study evaluated the relationship between microtensile bond strength (μTBS) and occurrence of nanoleakage at the resin–dentin interface using the same specimens. Methods Resin–dentin-bonded micro-specimens (sticks with a size of 300 μm × 300 μm × 8 mm) were prepared using one of two material combinations (group I: Syntac classic/Tetric Ceram Cavifil: n = 57; group II: Prime & Bond NT/Spectrum TPH: n = 52). After immersion of the micro-specimens in 0.1% rhodamine-B solution for 1 h, nanoleakage was imaged nondestructively using a confocal laser scanning microscope (CLSM). Then the specimens were subjected to a μTBS test. Results For the influence of nanoleakage on μTBS with the Syntac classic/Tetric Ceram Cavifil group, the nonparametric Spearman correlation was 0.033 at p = 0.805. For the Prime & Bond NT/Spectrum TPH group, the nonparametric Spearman correlation was 0.077 at p = 0.584. Significance The degree of nanoleakage had no influence on microtensile bond strength for the Syntac classic/Tetric Ceram Cavifil or for the Prime & Bond NT/Spectrum TPH group.