The effect of obturation techniques on the push-out bond strength of a premixed bioceramic root canal sealer

Objectives: The aim of the study was to evaluate the effect of obturation techniques on the push-out bond strength of a premixed bioceramic (TotalFill BC) root canal sealer to root canal dentin surface. Methods: The palatal root canal of sixty extracted human maxillary first premolar were prepared with Mtwo rotary system, teeth were divided into two groups; according to the sealer to be obturated with; TotalFill BC sealer and AH Plus sealer. Each group was then divided into three subgroups (n = 10) according to the obturation technique; cold lateral compaction, single cone, and warm vertical compaction. After obturation teeth were stored in an incubator for two weeks. Three slices of 1.5 mm thickness were then obtained from each root. Bond strength of obturation materials to root dentine was measured using push-out test by universal testing machine. Data were analyzed using ANOVA followed by Tukey's test. Mode of failure was determined by optical microscope examination. Results: Overall, the push-out bond strength of TotalFill BC sealer was significantly higher than that of AH Plus sealer (P < 0.001). The obturation technique had no significant effect on the bond strength of TotalFill. While the bond strength of AH Plus was significantly affected, warm vertical compaction and single cone groups displayed lower bond strength than cold lateral compaction group (P < 0.05). Mixed mode of failure was most predominant in all groups. Conclusions: TotalFill BC sealer showed a higher push-out bond strength than AH Plus sealer, and the obturation technique significantly affected AH Plus sealer but not the TotalFill. Clinical Significance: Warm vertical compaction significantly reduced the bond strength of the resin based AH Plus sealer compared to cold lateral compaction, but this was not significant with the bioceramic TotalFill BC sealer. Single cone technique could be used with bioceramic sealer which make the obturation faster and easier.