Enamel Resistance to Demineralization and Bracket Debonding with ACTIVATM BioACTIVE-Cement

Introduction: This study aimed to compare ACTIVATM BioACTIVE-Cement and two conventional orthodontic bracket cements regarding the demineralization resistance and shear bond strength (SBS). Methods: Sixty extracted posterior teeth were randomly assigned to four groups: TransbondTM XT Adhesive Light Cure (Trans); GC Fuji ORTHOTM (Fuji); ACTIVA TM BioACTIVE-Cement without acid-etching (ActivaWOE); ACTIVA TM BioACTIVE-Cement with acid-etching (ActivaWE). Prior to bonding, all teeth were screened with DIAGNOdentTM to determine no demineralization was present and were assessed with MicroMet 2104 for Vickers microhardness at 12 standardized points on enamel. Brackets were bonded to the buccal surface of each tooth according to manufacturers' instructions. All samples were placed in a 0.05 M acetate buffer, pH 5.0 for 96 hours. After demineralization, brackets were de-bonded with a universal testing machine to determine SBS. All samples were tested again with DIAGNOdent to detect demineralization, and with MicroMet for Vickers microhardness at points 50 μm distal (occlusal and cervical) and 50μm cervical (mesial and distal) to each original standardized point. DIAGNOdent values, Vickers microhardness, and SBS between the four groups were compared. Results: Microhardness reductions after demineralization were 56.4, 58.7, 100.1, and 126.9 for ActivaWOE, ActivaWE, Fuji, and Trans, respectively. The microhardness reductions of ActivaWOE and ActivaWE were not statistically different. SBS was 8.9 MPa for Trans, 7.6 MPa for ActivaWE, 3.8 MPa for Fuji, and 2 MPa for ActivaWOE. There was no significant difference in SBS between ActivaWE and Trans. Conclusion: ActivaWE for 10 seconds provided a similar SBS while significantly reduced the demineralization of enamel around brackets in comparison with the well-established resin cement, TransbondTM XT Adhesive Light Cure.