Bacterial sealing ability of calcium silicate-based sealer for endodontic surgery: an in-vitro study.

BACKGROUND: Apical surgery with standard retrograde maneuvers may be challenging in certain cases. Simplifying apical surgery to reduce operating time and streamline retrograde manipulation is an emerging need in clinical endodontics. AIM OF THE STUDY: The aim of the study was to compare the bacterial sealing ability of a calcium silicate-based sealer with the single cone technique combined with root end resection only, and calcium silicate-based sealer as a retrograde filling versus MTA retrofilling, and to analyze bacterial viability using confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: In this in vitro experimental study, 50 extracted human maxillary incisor teeth were instrumented and randomly divided into five groups: three experimental groups, a positive control group, and a negative control group (n = 10/group). In the experimental groups, the roots were obturated using the single cone technique (SCT) and a calcium silicate-based sealer. In group 1, the roots were resected 3 mm from the apex with no further retrograde preparation or filling. In groups 2 and 3, the roots were resected, retroprepared, and retrofilled with either a calcium silicate-based sealer or MTA, respectively. Group 4 (positive control) was filled with a single gutta-percha cone without any sealer. In group 5 (negative control), the canals were left empty, and the roots were sealed with wax and nail varnish. A bacterial leakage model using Enterococcus faecalis was employed to assess the sealing ability over a 30-day period, checking for turbidity and analyzing colony forming units (CFUs) per milliliter. Five specimens from each group were examined using CLSM for bacterial viability. Data for the bacterial sealing ability were statistically analyzed using chi-squared and Kruskal-Wallis tests. RESULTS: The three experimental groups did not show significant differences in terms of bacterial leakage, or bacterial counts (CFUs) (P > 0.05). However, significant differences were observed when comparing the experimental groups to the positive control group. Notably, the calcium silicate-based sealer, when used as a retrofilling, yielded the best sealing ability. CLSM imaging revealed viable bacterial penetration in all the positive control group specimens while for the experimental groups, dead bacteria was the prominent feature seen. CONCLUSION: Within the limitations of this study, it could be concluded that the bacterial sealing ability of calcium silicate-based sealer with the single cone technique combined with root end resection only and calcium silicate-based sealer as a retrograde filling were comparable with MTA retrofilling during endodontic surgical procedures.

Evaluation of the Efficacy of Three Antimicrobial Agents Used for Regenerative Endodontics: An In Vitro Study.

Aim: To evaluate the antibacterial efficacy of double antibiotic paste (DAP), silver nanoparticle (AgNP) gel, and tailored amorphous multiporous bioactive glass (TAMP-BG) in concentrations suitable for regenerative endodontics (RE) against 3-week-old Enterococcus faecalis biofilms after 24 hours and 7 days. Results: Radicular human dentin specimens were prepared and inoculated with E. faecalis to form 3-week-old biofilms. DAP (1 mg/mL), AgNPs 0.02%, and TAMP-BG 100 mg/mL, in methylcellulose gel formulations, were used as antimicrobials. The biofilm disruption assay was done followed by quantification of bacterial colony-forming units and scanning electron microscopic analysis. Results showed that 1 mg/mL of DAP or AgNPs 0.02% provided significant antibiofilm effects at both time intervals. Both DAP and AgNPs significantly reduced bacterial counts and biofilms after 7 days compared with 24 hours. Furthermore, 100 mg/mL of TAMP-BG had a comparable antibiofilm effect, but it was less potent than DAP and AgNPs at both time intervals. Conclusions: DAP (1 mg/mL), 0.02% AgNPs, and TAMP-BG (100 mg/mL) can significantly reduce E. faecalis biofilms. However, complete elimination was only possible with DAP and AgNPs.