Comparison of the bond strength of selected adhesive dental systems to cortical bone under in vitro conditions.

The study was performed to compare the tensile bond strength attained between composite and bone and between bone and bone using two different adhesive systems (Clearfil New Bond and Histoacryl) in vitro. Sixty porcine bone specimens with a total thickness of 4.0 mm (+/- 0.5 mm) and a cortical layer of 1.5 mm (+/- 0.2 mm) were obtained under standardised conditions. Ten specimens each were assigned to four experimental groups: group A: Clearfil New Bond (bone-composite); group B: Clearfil New Bond (bone-bone); group C: Histoacryl (bone-composite); group D: Histoacryl (bone-bone). The tensile bond strength of the adhesive agents mentioned above was measured 15 min after application and also after light-curing of the composite filling material (Tetric Ceram, colour A2; groups A and C) using a universal testing machine. The tensile bond strength measured was as follows: group A 8.00 MPa (+/- 1.36 MPa), group B 6.39 MPa (+/- 2.05 MPa), group C 5.22 MPa (+/- 1.96 MPa), and group D 1.95 MPa (+/- 0.49 MPa). Tensile bond strength was significantly increased in group A compared to groups C and D (P < 0.05, Tukey's test). The values in group D were significantly reduced compared to all other groups (P < 0.05, Tukey's test). Despite the limitations of an in vitro investigation, it can be concluded that adhesive systems might be a useful alternative in bone bonding. The use of dentin adhesives seemed to produce higher bond strength to bone than that attained with the cyanoacrylate adhesive.