comparison of the microleakage of octacalcium phosphate and mineral trioxide aggregate for furcal perforation repair: an in-vitro study

objective: furcal perforation is an undesirable complication that may occur during root canal therapy and seriously compromises the prognosis of endodontic treatment. the prognosis of furcal perforation repair depends on the prevention of bacterial infection of the perforation site. thus, use of a biocompatible material for complete sealing of the perforation site is critically important. this study aimed to compare the microleakage of mineral trioxide aggregate (mta) and octacalcium phosphate (ocp) for furcal perforation repair.   methods: this experimental study was conducted on 70 human mandibular molars with divergent roots, intact furcation site and completely formed apices. the teeth were randomly divided into 4 groups of two experimental (n=30), one positive control and one negative control group (n=5). the furcation floor was then perforated. in the first and second experimental groups, furcation perforations were repaired with ocp and mta, respectively. in the positive control group, the perforation was left untreated and in the negative control group no furcal perforation was created. the access cavity in all groups was filled with cavit. the teeth were stored in 100% humidity for 48h. root apices were sealed with sticky wax and the entire external surface of teeth except for 0.5 mm around the perforation site was covered with two coats of nail polish. the specimens were immersed in india ink for 4 days and then sectioned in half buccolingually. the sections were separated and dye penetration was evaluated using a stereomicroscope at 25x magnification. obtained data were analyzed using independent t-test.   results: no microleakage was observed in the negative control group. in the positive control group, the dye had completely penetrated into the walls. the amount of dye penetration was 1.64 and 1.22 mm in the ocp and mta groups, respectively. statistical analysis of data revealed that the sealability of mta was significantly greater than that of ocp (p<0.0001). conclusion: ocp cannot be an acceptable alternative to mta in terms of sealability.