Investigation of the effect of irrigation solutions at different temperatures on the bond strength of bioceramic based canal sealer

Aim The aim of this study was to evaluate the effect of irrigation solutions at different temperatures on the bond strength of bioceramic-based root canal paste using push-out test. Materials and Methods In our study, 72 mandibular premolar teeth with single root and canal were used. The teeth were randomly divided into 6 groups (n=12); Group 1: 5 ml 5% sodium hypochlorite (NaOCl) at 22 °C + 5 ml 17% ethylenediamine tetra acetic acid (EDTA) at 22 °C, Group 2: 5 ml 5% NaOCl at 37 °C + 5 ml 17% EDTA at 37 °C, Group 3: 5 ml 5% NaOCl at 22 °C + 5 ml 17% glycolic acid (GA) at 22 °C, Group 4: 5 ml 5% NaOCl at 37 °C + 5 ml 17% GA at 37 °C, Group 5: Dual Rinse (HEDP) (Medcem, Weinfelden, Switzerland) used in combination with 20 ml 5% NaOCl at 22 °C, Group 6: Dual Rinse HEDP used in combination with 20 ml 5% NaOCl at 37 °C. Root canals were prepared with Reciproc R40 (VDW, Munich, Germany) NiTi files with apical diameter #40. In the first four groups, final irrigation was completed with 5 ml of standard NaOCl solution volume at 22 °C and 37 °C, while in the 5th and 6th groups, final irrigation was completed with 10 ml of Dual Rinse HEDP mixture used in combination with 5% NaOCl at 22 °C and 37 °C. In all groups, the chelating agents used in the final irrigation were activated by passive ultrasonic irrigation (PUI) activation for 30 s. The canals were washed with 5 ml of distilled water, dried with paper cones, and canal filling was completed by single cone filling method using R40 gutta percha and AH Plus Bioceramic (AHBC; Dentsply Sirona, York, PA, USA) root canal paste. Samples were kept in the incubator for one week. Two 1 mm thick horizontal sections were taken from the apical 2 mm and 5 mm levels of the roots under water cooling using an IsoMet device (IsoMet, Buehler, Lake Bluff, IL, USA) and a 0.3 mm thick diamond disc (Metkon, Microcut precisioncutter, Bursa, Turkey). The specimens were subjected to the thrust test method using a Universal Testing Machine (Instron, Canton, MA, USA) with a stainless steel test tip with diameters of 0.8 mm in the middle third and 0.3 mm in the apical third, suitable for the canal filling diameter, with a loading speed of 1 mm/min. Three-way ANOVA test was used to compare the bond strength values, which followed a normal distribution according to solution, temperature and cross-section. Results The main effect of solution was statistically significant on the mean values of bond strength (p=0.020). The main effect of temperature was statistically significant on the mean values of bond strength (p<0.001). The main effect of cross-section was statistically significant on the mean values of bond strength (p<0.001). Conclusion EDTA solution significantly increased the binding strength compared to Dual Rinse HEDP solution. The bond strengths of the solutions increased with increasing temperature. The bond strengths in the apical region were found to be lower than the middle region. Key words: Continuous chelation, Dual Rinse, EDTA, Glycolic acid, push-out binding strength