The Effect of Obturation Technique on the Push-out Bond Strength of Calcium Silicate Sealers

Introduction: Calcium silicate based sealers are known to have excellent sealing ability and bioactivities. They are typically recommended to be used in a single-cone (SC) technique. No studies have evaluated the effects of the thermoplastic obturation technique on the dentin interface of these sealers. The purpose of this study was to evaluate the push-out bond strengths of MTA Plus Sealer (Avalon Biomed Inc, Bradenton, FL) and Endo Sequence BC Sealer (BC; Brasseler USA, Savannah, GA) when they were used in a thermoplastic technique. Methods: Fifty single-rooted human extracted teeth were randomly divided into 5 groups (n = 10), instrumented, and obturated with the SC technique or continuous wave (CW) technique: group 1, BC-SC; group 2, BC-CW; group 3, MTA Plus SC; group 4, MTA Plus CW; and group 5, AH Plus (Dentsply DeTrey, Konstanz, Germany) CW. The roots were sectioned into 1.0-mm-thick slices, and bond strengths were measured using a standardized push-out test. The mode of failure was determined by visual inspection under magnification. Results: The MTA Plus CW had statistically significant lower bond strengths than all other groups. The BC-SC group had statistically higher bond strengths than the MTA Plus SC and AH Plus CW groups. No significant differences were seen among the other groups. Modes of failure were predominately cohesive or mixed except for group 4 (ie, MTA Plus-CVV) in which nearly half the specimens had no visible sealer. Conclusions: BC and MTA Plus sealer showed favorable bond strengths when used in an SC technique. The CW obturation technique decreased the bond strengths of these sealers.