MTA versus Portland cement as repair material for furcal perforations: a laboratory study using a polymicrobial leakage model

AIM: To compare the ability of Portland cement and mineral trioxide aggregate (MTA) to prevent coronal leakage through repaired furcal perforations in molar teeth. METHODOLOGY: The pulp chambers of 36 human mandibular molar teeth were accessed and the root canal orifices were located. The roots were horizontally sectioned in the middle third. Composite resin was used to fill the root canal orifices and the apical end of the roots. Perforations were created in the centre of the pulp chamber floor using a size 3 round bur. Thirty teeth were divided into two groups (n = 15) and a further six teeth served as controls. In G1, all 15 perforation defects were repaired with MTA while in G2, Portland cement was used. Each tooth was inserted in a silicone tube (bacterial reservoir) with the region containing the perforation protruding through the end. The system was sterilized and placed in a glass flask containing sterile brain heart infusion medium (BHI). The reservoirs were filled with human saliva mixed in BHI and system was incubated at 37 degrees C and checked daily for the appearance of turbidity in the BHI broth during the following 50 days. The leakage data were analysed statistically by a log-rank test (P < 0.05). RESULTS: Eight (53%) of the 15 samples of the MTA group (G1) and nine (60%) of the 15 samples of the Portland cement group (G2) were fully contaminated at 50 days. There was no statistically significant difference between the two groups (P > 0.05). CONCLUSION: Portland cement and MTA demonstrated a similar ability to seal furcal perforations.