Objectives. To evaluate the push-out bond strength of experimental apatite calcium phosphate coated gutta-percha (HAGP) compared to different commercially available coated gutta-percha root obturation points. Methods. Extracted teeth were selected and instrumented using ProTaper rotary files. The canals were assigned into five equal groups and obturated using matching single cone technique as follows: EndoREZ cones and EndoREZ sealer, Bioceramic Endosequence gutta-percha (BCGP) with Endosequence BC sealer, Active GP with Endosequence BC sealer (ActiV GP), conventional GP with Endosequence BC sealer, and HAGP with Endosequence BC sealer. Each root was sectioned transversally at the thickness of 1±0.1 mm to obtain 5 sections (n=25 per group). The specimens were subjected to push-out test using a Universal Test Machine at a loading speed of 0.5 mm/ min. Failure modes after push-out test was examined under stereomicroscope and the push-out data were analyzed using ANOVA and the post hoc Dunnett T3 test (p = 0.05). Results. The highest mean bond strength was yielded by HAGP followed by BCGP, ActiV GP, conventional GP, and EndoREZ. There were significant differences between EndoREZ and all other groups (p<0.001). The prominent failure mode of HAGP was mixed mode, whereas EndoREZ exhibited adhesive failure mode. Conventional GP, ActiV GP, and BCGP showed cohesive failure mode. Conclusion. HAGP showed promising results to be used as root canal filling material in combination with bioceramic sealer.

This study compared the chemical and physical properties of an experimental radiopaque white Portland cement (REPC) with reduced particle size to ProRoot white mineral trioxide aggregate (WMTA). The particle size distribution of experimental Portland cement (EPC) was examined, and then nano-zirconium oxide (nano-ZrO) was added to produce REPC. Chemical analysis, initial setting time, pH values, and push-out bond strength were evaluated. Results showed that REPC had smallest particle size (354.5±26.45 nm), while PC had the largest (1,309.67±60.54 nm) (p<0.05). Differences in chemical composition were observed. REPC exhibited shorter setting time (32.7±0.58 min) compared to WMTA (131.67±2.89 min) and PC (163.33±2.89 min) (p<0.05). All groups showed alkaline pH (p<0.05). REPC demonstrated the highest push-out bond strength (22.24±4.33 MPa) compared with WMTA (15.53±3.26 MPa) and PC (16.8±5.43 MPa) (p<0.05). This cost-effective PC formulation reduced the setting time and increased the push-out bond strength while maintaining the alkaline properties of the original cements.

Aims: This study aimed to assess the apical sealing ability of experimental apatite-coated gutta-percha points compared to various coated gutta-percha root filling materials. Study Design: Experimental in-vitro study. Place and Duration of Study: Department of Restorative Dentistry, University of Malaya, June 2014 and November 2014. Methodology: Ninety-six extracted permanent maxillary central incisors were standardized and prepared by ProTaper universal rotary files. The specimens were allocated into six groups (n=15) and filled using matching single cone technique as follows; EndoREZ points with EndoREZ sealer, Bioceramic coated points (BCGP), Active GP (ActiV GP), Conventional gutta-percha (GP), apatite coated GP (HAGP) all in combination with Endosequence BC sealer. The sixth group was filled using cold lateral compaction of Conventional GP and Endosequence BC sealer. The specimens were subjected to a dye leakage test. The remaining six teeth were divided equally to be used as a negative and positive control. One-way analysis of variance (ANOVA) followed by the post hoc Dunnett T3 test was performed for data analysis, and the significance value was set at P =.05. Results: ActiV GP had the least leakage followed by BCGP, HAGP, cold lateral compaction, conventional GP, and EndoRez. Conclusion: HAGP as root canal filling showed favourable sealing ability comparable to ActiV GP, BCGP, and conventional GP and it was superior to EndoREZ.