effect of calcium hydroxide on the push-out bond strength of endodontic biomaterials in simulated furcation perforations

introduction: the aim of this in vitro study was to evaluate the effect of calcium hydroxide (ch) on push-out bond strength of white mineral trioxide aggregate (wmta) and calcium-enriched mixture (cem) cement in simulated furcation perforations. methods and materials: furcation perforations, measuring 1.3 mm in diameter and 2 mm in height, were created in 80 human mandibular first molars. the teeth were then divided into 4 groups ( n =20). in groups 1 and 3 ch was placed in the perforation for one week, before placement of wmta and cem. in groups 2 and 4 perforations were repaired without placement of ch. in groups 1 and 2 the perforation sites were repaired with wmta and cem cement was used in groups 3 and 4. after 7 days, the push-out test was carried out using a universal testing machine. data were analyzed with two-way anova. the level of significance was set at 0.05. results: the maximum and minimum bond strength values were recorded in the wmta/ch (13.08±1.8 mpa) and cem cement groups (8.03±0.98 mpa), respectively. there were significant differences in resistance to dislodgement between the wmta/ch and other groups ( p <0.05). conclusion: placement of ch before placement of wmta in furcation perforation improves the push-out bond strength of this material.