The Effect of Acidity on Dislodgment Resistance of Mineral Trioxide Aggregate and Bioaggregate in Furcation Perforations: An In Vitro Comparative Study

Introduction: The aim of this study was to compare the effect of acidic environment on the dislodgement resistance of mineral trioxide aggregate (MTA) and Bio-aggregate (Innovative BioCeramix, Vancouver, Canada) when used as perforation repair materials. Methods: Eighty, human, mandibular molars were used. Perforations were made in the furcation of each molar and enlarged to #4 Pesso drills. After perforation repair, specimens of each material were randomly divided into 4 groups (n = 10) according to storage media and time: group A: phosphate-buffered saline (PBS) (pH = 7.4) for 4 days, group B: acetic acid (pH = 5.4) for 4 days, group C: PBS for 34 days, and group D: acetic acid (pH = 5.4) for 4 days followed by exposure to PBS for 30 days. Dislodgment resistance was then measured using a universal testing machine, and then the specimens were vertically split to examine the perforated dentin wall using scanning electron microscopy. Results: MTA resisted dislodgement more efficiently than BA after 4 days in PBS (P < .05). The dislodgment resistance of MTA was significantly reduced (P < .05) after exposure to acetic acid, whereas BA was not affected (P > .05). There was an increase in the dislodgment resistance with the increase in the storage time to 34 days (P < .01). After 34 days, there was a statistically significant difference among groups; the MTA D group had significantly the highest bond strength, and the BA D group D had the lowest (P < .05). Conclusions: MTA is more influenced by acidic pH than BA. Storage for 30 days in PBS can reverse the affected bond of MTA by the acidic environment. (J Endod 2012;38:245-249)