IADR Abstract Archives
Enamel Resistance to Demineralization and Bracket Debonding With ACTIVATM BioACTIVE-CEMENT
Objectives: To compare ACTIVATM BioACTIVE-CEMENT with two conventional orthodontic bracket cements regarding the demineralization resistance and shear bond strength (SBS).
Methods: Sixty extracted posterior teeth were equally assigned to four groups: TransbondTM XT Adhesive Light Cure (3M Unitek) (Trans); GC Fuji ORTHOTM (GC America) (Fuji); ACTIVATM BioACTIVE-CEMENT without acid-etching (Pulpdent)(ActivaWOE); ACTIVATM BioACTIVE-CEMENT with acid-etching (Pulpdent)(ActivaWE). Prior to bonding, all teeth were screened with DIAGNOdentTM (KaVO) to determine no demineralization was present and were assessed with MicroMet 2104 (Buehler) for Vickers microhardness at 12 standardized points on enamel, 50µm adjacent to each bracket edge, with three points on each edge. Brackets (OrmcoTM) 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 (Instron® 5566A Norwood, MA) to determine shear bond strength at a cross-head speed of 0.5 mm/min. 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 using the one-way ANOVA with Bonferroni method for post-hoc pairwise comparisons. All p-values less than 0.05 were considered statistically significant.
Results: DIAGNOdent values were not significantly different between the four groups (Table 1), but the baseline microhardness was significantly different (Table 2). The microhardness values post-demineralization decreased in all four groups. ActivaWE and ActivaWOE displayed the lowest reduction in microhardness. ActivaWE displayed the highest SBS. ActivaWOE and Fuji displayed the lowest SBS of the four groups.
Conclusions: The results of this study indicate that ActivaWE for 10 seconds has increased SBS while exhibiting less demineralization of tooth structure.
Methods: Sixty extracted posterior teeth were equally assigned to four groups: TransbondTM XT Adhesive Light Cure (3M Unitek) (Trans); GC Fuji ORTHOTM (GC America) (Fuji); ACTIVATM BioACTIVE-CEMENT without acid-etching (Pulpdent)(ActivaWOE); ACTIVATM BioACTIVE-CEMENT with acid-etching (Pulpdent)(ActivaWE). Prior to bonding, all teeth were screened with DIAGNOdentTM (KaVO) to determine no demineralization was present and were assessed with MicroMet 2104 (Buehler) for Vickers microhardness at 12 standardized points on enamel, 50µm adjacent to each bracket edge, with three points on each edge. Brackets (OrmcoTM) 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 (Instron® 5566A Norwood, MA) to determine shear bond strength at a cross-head speed of 0.5 mm/min. 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 using the one-way ANOVA with Bonferroni method for post-hoc pairwise comparisons. All p-values less than 0.05 were considered statistically significant.
Results: DIAGNOdent values were not significantly different between the four groups (Table 1), but the baseline microhardness was significantly different (Table 2). The microhardness values post-demineralization decreased in all four groups. ActivaWE and ActivaWOE displayed the lowest reduction in microhardness. ActivaWE displayed the highest SBS. ActivaWOE and Fuji displayed the lowest SBS of the four groups.
Conclusions: The results of this study indicate that ActivaWE for 10 seconds has increased SBS while exhibiting less demineralization of tooth structure.
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