Effect of acidulated phosphate fluoride and casein phosphopeptide-amorphous calcium phosphate application on shear bond strength of orthodontic brackets

Abstract

Objective: To evaluate the effect of a recently introduced prophylactic agent, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), on shear bond strength of brackets and compare it with the effect of acidulated phosphate fluoride (APF). Materials and Methods: Forty-eight freshly extracted mandibular bovine incisors were used. Teeth were randomly divided into four groups (n = 12) as follows: group 1 served as control, and no pretreatment was performed on the enamel; group 2, enamel was treated with 1.23% APF and CPP-ACP, respectively; group 3, enamel was treated with CPP-ACP; and group 4, enamel was treated with 1.23% APF for 4 minutes. In all groups, brackets were bonded using a conventional acid-etch and bond system (Transbond XT, 3M Unitek, Monrovia, Calif). Bonded specimens were first stored in deionized water at 37°C for 24 hours, subjected to thermal cycling for 1000 cycles, and further stored in distilled water for 6 weeks before debonding procedures. After debonding, teeth and brackets were examined under a stereomicroscope at 10x magnification for any adhesive remaining, in accordance with the modified adhesive remnant index. Results: The shear bond strengths of all experimental groups were significantly higher than that of the control group (P < .01). There was no significant difference between the shear bond strengths of the experimental groups (P > .05). Conclusion: The use of CPP-ACP either alone or combined with APF could be considered as an alternative prophylactic application in orthodontic practice since it did not compromise bracket bond strength. © 2008 by The EH Angle Education and Research Foundation, Inc.