Objective: To investigate the tissue dissolution efficacy of different concentrations of sodium hypochlorite (NaOCl) using the GentleWave® technology (GW) and compare it with that of passive ultrasonic irrigation. This study will provide a novel in vitro model used to evaluate the tissue dissolution efficacy of different concentrations of NaOCl using the GentleWave® procedure. Materials and Methods: Palatal bovine tissue was standardized by weight at 70-75 mg (average of 74.4 mg). The samples were divided into three groups of n = 10, Group 1: GW + 0.5% NaOCl, Group 2: GW + 3% NaOCl, and Group 3: ultrasonic group (US) + 6% NaOCl, and a control group of n = 2 with GW + H2O. A specialized CleanFlow instrument was manufactured for the GW groups. For the US group, an apparatus was developed to allow the tissue to be in close contact with a freely operating ultrasonic tip. Each group was operated with its specific irrigants and dissolution times were obtained unless the samples were not visually dissolved within 5 min, and the dissolution rates were calculated. Dissolution times and rates were analyzed using univariate analysis of variance followed by a t-test. Results: The GW groups with 0.5% and 3% NaOCl dissolved entire tissue samples within 5 min and had average dissolution times of 227.5 s (Group 1) and 81.5 s (Group 2). GW with water had a higher tissue dissolution rate than ultrasonics with 6% NaOCl. Conclusions: The GentleWave® using a lower concentration of NaOCl showed a similar clinical efficacy of dissolving tissues but displayed a significantly faster rate when compared with passive ultrasonic agitation.

To evaluate the efficacy of multi-functional root canal irrigating solutions in the removal of canal wall smear layers, antibacterial activity, cytotoxicity, and tissue dissolution efficacy.

Forty single-rooted teeth were mechanically instrumented and irrigated with Triton, EndoJuice™, EDTA, and 0.9 % saline. Each tooth was evaluated for smear layer removal using scanning electron microscopy. Antibacterial activity of the irrigants was assessed against Enterococcus faecalis biofilms using colony-forming unit analysis. Neutral red, clonogenic, and cytokinesis-block micronucleus assays were performed on Chinese hamster V79 cells to evaluate the short-term and long-term cytotoxicity and genotoxicity of the irrigants. Tissue dissolution efficacy was tested on shrimp meat placed in resorptive cavities prepared in root canals.

EndoJuice™ and EDTA showed better smear layer removal than Triton in the coronal-third and middle-third of the canal walls. There was no significant difference between EndoJuice™ and EDTA. In the apical-third, EndoJuice™ removed the smear layer more effectively than EDTA and Triton. Specimens treated with saline were heavily smeared. Triton and sodium hypochlorite were similar in reducing intracanal E. faecalis counts, while specimens treated with EndoJuice™ had higher colony-forming units compared to Triton or sodium hypochlorite. EndoJuice™ was less cytotoxic and genotoxic compared to Triton. Sodium hypochlorite dissolved the most soft tissue, followed by Triton and EndoJuice™.

EndoJuice™ was less toxic and more effective in smear layer removal. Triton demonstrated better antimicrobial activity and tissue dissolution efficacy.

Evaluating the smear layer removal, antibacterial activity, toxicity, and tissue dissolution abilities of multi-functional root canal irrigants is essential to ensure their effectiveness and safety for clinical use in root canal treatment.

This systematic review aims to provide preclinical evidence of the antimicrobial efficacy of natural endodontic solutions (NES) compared to sodium hypochlorite (NaOCl) and chlorhexidine (CHX) against Enterococcus faecalis. The study followed the PRISMA guidelines and had a registered protocol (PROSPERO - CRD42021224022). The inclusion criteria comprised ex vivo studies simulating root canal irrigation to assess the standardized mean difference of colony-forming units (CFUs). Records were systematically identified in PubMed, Scopus, EMBASE, SciELO, Web of Science, LILACS, DANS Easy, and BDTD databases in January 2024. The RoBDEMAT tool helped determine the risk of bias. As for the network meta-analysis, CFU data were collected pre- and post-irrigation protocols as an effect measure. Thirty-five studies met the eligibility criteria and were included in the qualitative analysis, and seven studies were eligible for the network meta-analysis. The total sample consisted of 1,504 root canals. Among the tested solutions, apple cider vinegar combined with 2.5% NaOCl showed the highest probability of reducing CFUs after root canal irrigation (95%CI: -0.76-0.20), followed by 2% CHX and NaOCl (considering the different concentrations [95%CI: -0.32-0.17]). The bias assessment revealed significant omissions in reporting, particularly regarding sample size calculation, sample randomization, and operator blinding. The obtained evidence demonstrated that, even though NES did not overcome NaOCl, they have antimicrobial potential against Enterococcus faecalis.

Background and Objective: Eliminating intracanal Enterococcus faecalis (E. faecalis) is challenging because of its ability to penetrate deep dentinal tubules and its high resistance to many chemicals. This study evaluated the effectiveness of conventional needle irrigation and three different irrigant activation methods in reducing E. faecalis. Methods: The root canals of extracted teeth were shaped, contaminated with E. faecalis, and incubated for three weeks. They were randomly allocated to four experimental groups of 15 teeth each according to the final irrigation method: group 1, conventional needle irrigation; group 2, passive ultrasonic (PU) irrigation; group 3, XP-endo Finisher (XPF); and group 4, laser-activated (LA) irrigation. Bacterial samples were taken and cultured before and after these final irrigation procedures. The colony-forming units were counted, and the bacterial reduction percentages of each group were calculated. The Kruskal-Wallis and Dunnet tests were used for statistical analysis. Results: All irrigant activation methods were significantly more effective than conventional needle irrigation. Although the LA group generated more negative samples than PU, there was no statistically significant difference between the LA and PU groups. LA was significantly more effective than the XPF, whereas PU and XPF were statistically similar. Conclusions: Within the limitations of this study, the final irrigation with LA and PU showed the best reductive effect on E. faecalis colonies. Considering that the LA group had more negative samples, it may be chosen as an alternative to enhance root canal disinfection, especially in difficult cases.

This study aimed to evaluate whether the use of 8.25% sodium hypochlorite (NaOCl), compared with the use of 2.5% NaOCl, leads to higher postoperative pain after endodontic treatment.

A total of 154 patients were randomly assigned into 2 groups: 8.25% and 2.5% NaOCl. A single-visit endodontic treatment was performed using a standard protocol, varying only the NaOCl concentration. Postoperative pain was assessed using the numeric rating scale at multiple times over 30 days. Overall pain scores over time were explored via multilevel mixed-effects negative binomial regression. The need for pain medication was recorded and compared between groups via the Mann-Whitney U test.

The use of 8.25% NaOCl increased postoperative pain scores over time by 3.48 times compared with the use of 2.5% NaOCl (incident rate ratio [IRR], 3.48; 95% CI, 1.57 to 7.67). Furthermore, the 8.25% NaOCl group exhibited higher pain incidence than the 2.5% NaOCl group during the 12-hour through 3-day period, with scores at these times ranging from 2.21 (IRR, 2.21; 95% CI, 1.35 to 3.62) through 10.74 (IRR, 10.74; 95% CI, 3.74 to 30.87) higher. No difference was detected in the number of analgesic capsules administered between groups.

The use of 8.25% NaOCl resulted in higher postoperative pain than the use of 2.5% NaOCl, with pain scores increasing by 3.48 times when this solution was used. Furthermore, the 8.25% NaOCl group exhibited higher pain incidence than the 2.5% NaOCl group during the 12-hour through 3-day period.

The use of 8.25% NaOCl during endodontic treatment can increase postoperative pain significantly. This clinical trial was registered at the Brazilian Registry of Clinical Trials database (RBR-6vq3hc4).

This review article explores the fundamental principles of modern endodontics with a focus on root canal cleaning and shaping. It reviews commonly used endodontic irrigant, namely sodium hypochlorite (NaOCl), herbal extracts, chlorhexidine (CHX), and chelating agents, highlighting their properties, applications, and potential drawbacks. NaOCl, a key antimicrobial agent, demonstrates effectiveness against various microorganisms but poses challenges such as high cytotoxicity. Herbal extracts, gaining recognition in endodontics, present an alternative with potential advantages in preserving dentin integrity. CHX, known for its broad-spectrum antimicrobial activity, is discussed in both liquid and gel formulations, emphasizing its role in reducing smear layer formation and preserving hybrid layer durability. Chelating agents, specifically ethylenediaminetetraacetic acid and citric acid, play a vital role in removing the smear layer, enhancing dentin permeability, and facilitating the penetration of antimicrobial agents. The review article underscores the importance of careful application and consideration of each irrigant's properties to ensure safe and effective endodontic procedures. It serves as a valuable guide for clinicians in selecting appropriate irrigants based on specific treatment requirements.

To determine the prevalence of postoperative pain after endodontic treatment using low (LC) and high (HC) concentrations of sodium hypochlorite (NaOCl).

Six databases and the grey literature were searched to identify randomized clinical trials that evaluated postoperative pain after endodontic treatment using NaOCl. NaOCl concentrations were dichotomized into 'LC' (0.5% to 3%) and 'HC' (≥ 5%) and a proportion meta-analysis was applied to determine the postoperative pain prevalence: overall and according to pain intensity and postoperative time. The prevalence of patients using pain control medication was also determined. A significance level of 5% and a random effect model were applied for data analysis. Between-study heterogeneity was assessed by I2 index. Risk of bias (RoB) was assessed using the Cochrane Risk-of-Bias 2.0 tool. The certainty of evidence was assessed using the GRADE approach.

Ten studies were included in the review and eight in the meta-analysis. The overall prevalence of postoperative pain was 45% in LC and 39% in HC. The prevalence of pain in LC and HC after 24 h was 25% and 40%, respectively. After 48 h, the prevalence decreased to 10% in LC and 25% in HC. 'Absent pain' was the most prevalent score. The prevalence of patients who used medication was 9% in LC and 15% in HC. Three studies were classified as 'high RoB', five as 'low RoB', and two as 'some concerns'. The certainty of evidence was very low.

The overall prevalence of postoperative pain after endodontic treatment using LC and HC of NaOCl was 45% and 39%, respectively.

Postoperative pain is common after endodontic treatment using NaOCl, but tends to decrease over time.

The success of root canal therapy depends mainly on the complete elimination of the root canal bacterial biofilm. The validity and biocompatibility of root canal disinfectant materials are imperative for the success of root canal treatment. However, the insufficiency of the currently available root canal disinfectant materials highlights that more advanced materials are still needed. In this study, a nanozyme-loaded hydrogel (Fe3O4-CaO2-Hydrogel) was modified and analyzed as a root canal disinfectant material. Fe3O4-CaO2-Hydrogel was fabricated and examined for its release profile, biocompatibility, and antibacterial activity against E. faecalis and S. sanguis biofilms in vitro. Furthermore, its efficiency in eliminating the root canal bacterial biofilm removal in SD rat teeth was also evaluated. The results in vitro showed that Fe3O4-CaO2-Hydrogel could release reactive oxygen species (ROS). Moreover, it showed good biocompatibility, disrupting bacterial cell membranes, and inhibiting exopolysaccharide production (p < 0.0001). In addition, in vivo results showed that Fe3O4-CaO2-Hydrogel strongly scavenged on root canal biofilm infection and prevented further inflammation expansion (p < 0.05). Altogether, suggesting that Fe3O4-CaO2-Hydrogel can be used as a new effective biocompatible root canal disinfectant material. Our research provides a broad prospect for clinical root canal disinfection, even extended to other refractory infections in deep sites.

The aim of this study was to evaluate the postoperative pain in patients after endodontic treatment using 8.25% sodium hypochlorite (NaOCl) compared with other concentrations and 2% chlorhexidine (CHX).

In this double-blind randomized trial, 180 patients were evaluated who underwent a single session of endodontic treatment under irrigation with 2.5%, 5.25%, or 8.25% NaOCl or 2% CHX solutions. The presence of postoperative pain was assessed 24, 48, and 72 hours after treatment and recorded using the visual analog scale (VAS). A descriptive analysis, logistic regression, and Wald test were performed.

Altogether 169 patients participated, of whom 107 were women, and the mean age was 38.1 ± 14.4 years. No significant differences occurred between the irrigants and the pain outcomes, not even for the use of postoperative pain medication and responses to VAS (P > .05). In the multivariate model including irrigants, after 24 hours or at any time, a significant difference (P < .05) remained in preparation time ≥10 minutes and the presence of overfilling. Also, in relation to the VAS, the overfilling presented significantly different results (P < .05).

There was no significant difference in the presence of postoperative pain between the 8.25% NaOCl and the other irrigation solutions. However, the extended preparation time and the overfilling material were responsible for the increase of postoperative pain.