Partial restoration of fracture resistance in mandibular molars: A comparative study of Bio MTA+ and calcium-enriched mixture for furcal perforation repair

Objective Furcal perforations are iatrogenic complications which compromise the biological and mechanical integrity of endodontically treated teeth. Although calcium silicate-based materials are widely used for perforation repair, their ability to restore fracture resistance remains unclear. This study aimed to evaluate the fracture strength of mandibular molars with simulated furcal perforations repaired using Bio MTA+ or calcium-enriched mixture (CEM). Method Seventy-six extracted human mandibular molars were randomly allocated into four groups (n = 19): negative control (no perforation), positive control (perforation without repair), Bio MTA+ (perforation repaired with Bio MTA+) and CEM (perforation repaired with CEM). Standardised root canal treatments were performed on all specimens, followed by perforation and repair procedures where applicable. Fracture strength was measured using a universal testing machine at a crosshead speed of 1 mm/min. The data were analysed using one-way ANOVA and Tukey’s HSD test. Results A statistically significant difference was observed among the groups (F(3,72) = 52.362, p < 0.001). The negative control group exhibited the highest fracture strength values, whereas the positive control group presented the lowest. Both Bio MTA+ and CEM groups demonstrated significantly higher fracture strength than the positive control group (p < 0.05), but significantly lower values than the negative control group (p < 0.05). No statistically significant difference was found between Bio MTA+ and CEM (p = 0.773). Conclusion Furcal perforations significantly reduce the fracture resistance of endodontically treated teeth. Repair with calcium silicate–based materials improves mechanical strength but does not restore it to the level of endodontically treated teeth without perforation. Bio MTA+ and CEM demonstrated comparable performance and may be considered suitable options for furcal perforation repair.