Background/Objectives: To assess the cytocompatibility, antibacterial and anti-biofilm efficacy of grape seed extract (GSE) and quercetin hydrogels versus calcium hydroxide (CH) as intracanal medications (ICMs) against an endodontic ex vivo biofilm model. Methods: Single-rooted teeth (n = 50) were prepared and sterilized before being infected with E. faecalis to develop a mature biofilm. They were divided into five equal groups according to the ICM used: G1: medicated with CH paste, G2: medicated with GSE hydrogel, G3: medicated with quercetin hydrogel, G4: positive control group that was infected and not medicated, and G5: negative control group that was neither infected nor medicated. After 1 week, the ICM was removed, and the root canals were cultured to assess the antibacterial efficacy by counting the colony-forming units and the anti-biofilm efficacy by the crystal violet assay. Dead/live bacterial viability was assessed by CFLSM examination, while the cytocompatibility was assessed using the MTT assay. Results: CH had the best antibacterial efficacy, followed by GSE and quercetin hydrogels (p < 0.001). Regarding the anti-biofilm efficacy, GSE was superior, followed by quercetin and CH (p < 0.001). CFLSM examination showed CH and GSE hydrogel to be highly effective in comparison to the positive control (p < 0.0001), with no statistical difference between them (p > 0.05). CH showed significantly higher cell viability percentages using a 500 μg/mL, while quercetin and GSE started to show cell viability > 70% at concentrations of 125 μg/mL and 62.5 μg/mL. Conclusions: CH fulfilled the ideal requirements of ICM as being both antibacterial and non-cytotoxic compared to the other materials tested.

Background: This is a triple-blinded, prospective split-mouth clinical trial. It is important to shed light on the effect of different apical preparation sizes regarding postoperative pain within the same patient with the same pulpal histological status. The aim is to compare and evaluate the severity of postoperative pain following apical enlargement with two different sizes after the IBF using the visual analogue scale. Methods: Fifty “teeth” in 25 patients were assigned into two equal groups (25 per group) using E3 Azure rotary files; Group A was prepared two sizes greater than the Initial binding file (IBF) (the largest K file to bind at the actual working length) mesial canals, which were enlarged to 35#/0.04 and 40#/0.04 for the distal canals. Group B was prepared in three sizes larger than the IBF: 40#/0.04 for mesial canals and 45#/0.04 for the distal canals. On a modified VAS form, patients were questioned to indicate the degree of their pain and assisted in narrating their pain intensity during the following periods: 12, 24, and 72 h, and after a week. VAS data were non-parametric and analyzed using the signed-rank test for intergroup comparisons, Freidman’s test, and the Nemenyi post hoc test for intragroup comparisons. The significance level was set at p < 0.05. Results: showed that regardless of measurement time, enlargement of apical preparation was significantly associated with higher pain scores (p < 0.001). Within both groups, there was a significant reduction of measured pain score with time, with values measured after 12 and 24 h being significantly higher than values measured at other intervals (p < 0.001) and with values measured after three days being significantly higher than 1-week value (p < 0.001). Conclusion: The size of apical preparation had a significant effect on postoperative pain. Trial registration number & date: NCT05847738, 08/05/2023.