Can surface preparation with CVD diamond tip influence on bonding to dental tissues?

This study evaluated the influence of chemical vapor deposition (CVD) tips surface treatments of enamel and dentin on bonding resistance of two adhesive systems. Thirty embedded samples were divided in 12 groups (n = 10), according to factors: substrate (enamel and dentin), adhesive system [etch-and-rinse (SB) and self-etch]; and the surface treatments (paper discs, impact CVD tips and tangential CVD tip). When CVD tip was used in the impact mode the tip was applied perpendicular to dental surface, while at tangential mode, the tip worked parallel to dental surface. Specimens were tested in tension after 24 h at 0.5 mm/min of cross-head speed. ANOVA results, in MPa showed that in enamel, only adhesive system factor was statistically significant (p = 0.015) under tested conditions, with higher bond strength observed for SB groups. However, in dentin the best bonding performance was obtained in SE groups (p = 0.00). In both tested substrates, results did not show statistically significant difference for factors treatment and its interactions.