The effects of non-thermal plasma and conventional treatments on the bond strength of fiber posts to resin cement

OBJECTIVES This study compared the effect of hexamethyldisiloxane (HMDSO) and ammonia (NH3) plasmas on the bond strength of resin cement to fiber posts with conventional treatments. MATERIALS AND METHODS Sixty-five fiber posts were divided into 5 groups: Control (no surface treatment); H2O2 (24% hydrogen peroxide for 1 min); Blasting (blasting with aluminum oxide for 30 sec); NH3 (NH3 plasma treatment for 3 min); HMDSO (HMDSO plasma treatment for 15 min). After the treatments, the Ambar adhesive (FGM Dental Products) was applied to the post surface (n = 10). The fiber post was inserted into a silicon matrix that was filled with the conventional resin cement Allcem Core (FGM). Afterwards, the post/cement specimens were cut into discs and subjected to a push-out bond strength (POBS) test. Additionally, 3 posts in each group were evaluated using scanning electron microscopy. The POBS data were analyzed by one-way analysis of variance and the Tukey's honest significant difference post hoc test (α = 0.05). RESULTS The Blasting and NH3 groups showed the highest POBS values. The HMDSO group showed intermediate POBS values, whereas the Control and H2O2 groups showed the lowest POBS values. CONCLUSION Blasting and NH3 plasma treatments were associated with stronger bonding of the conventional resin cement Allcem to fiber posts, in a procedure in which the Ambar adhesive was used.