Bond strength and nanoroughness assessment on human pretreated cementum surfaces

Objectives: To determine the bond strength of seven adhesive systems to human cementum, and to assess the promoted surface roughness. Methods: Extracted human canines were used for the present study. The mesial surface from the cervical third of the roots were ground flat with wet 600-grit silicon carbide paper and bonded. Seven adhesive systems were employed: an etch-and-rinse adhesive (Single Bond), two two-step self-etching (Clearfil SE Bond and Resulcin Aquaprime) and four one-step self-etching (One-up Bond F, Prompt-L-Pop, Etch and Prime 3.0 and NRC+Prime&Bond NT). Composite build-ups were constructed and stored in a humid environment for 24 h at 37 °C. Specimens were sectioned into 1 mm² beams and tested for microtensile bond strength (MTBS). Additional surfaces were conditioned for atomic force microscopy (AFM) analysis. Results were analyzed with ANOVA and Student-Newman-Keuls tests (P < 0.05). Results: Single Bond showed the highest MTBS values. No differences were found between Resulcin Aquaprime, One-up Bond and Prompt-L-Pop. Clearfil SE Bond, Etch and Prime and NRC+Prime&Bond NT obtained the lowest bond strength values. H₃PO₄ acid treatment of cementum and Resulcin Aquaprime showed the highest nanoroughness parameters and One-up Bond the lowest. Conclusion: The etch-and-rinse adhesive and the two-step self-etching adhesive with the lowest pH value promoted the highest bond strength to human cementum surfaces.