Ex vivo microbial leakage after using different final irrigation regimens with chlorhexidine

Sodium Hypochlorite Accidents in Endodontic Practice: Clinical Evidence and State of the Art

Sodium hypochlorite (NaOCl) is widely utilized in endodontics for its effective antimicrobial properties and ability to dissolve necrotic tissues. However, its use is not devoid of risks, including potential severe tissue damage and chemical burns. This systematic review evaluates the documented risks of using NaOCl in endodontic treatments. It compares its safety and efficacy with other endodontic irrigants, such as EDTA and chlorhexidine. This review followed the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" guidelines and registered with PROSPERO. Comprehensive searches were performed in PubMed, Scopus, Web of Science, and CENTRAL databases, with additional hand searches in grey literature. Studies were selected reporting adverse effects related to NaOCl used in endodontic procedures, ranging from randomized controlled trials to case reports. Data extraction and risk of bias assessment were systematically performed using standardized tools. Seventeen studies were included, detailing instances from chemical burns to severe allergic reactions and tissue necrosis associated with NaOCl use. The risk of bias was predominantly low across the studies. Sodium hypochlorite demonstrated a higher efficacy in microbial eradication and tissue dissolution than other irrigants, though it also showed a higher incidence of severe complications when mishandled. Sodium hypochlorite remains a cornerstone in endodontic disinfection due to its potent antimicrobial and tissue dissolution properties. However, its application must be meticulously managed to prevent complications. Future research should focus on optimizing concentrations and application techniques to enhance safety and effectiveness, potentially integrating safer alternatives or complementary solutions like EDTA to mitigate risks while preserving irrigant benefits.

Solubility and bacterial sealing ability of MTA and root-end filling materials

Objective

To evaluate solubility and sealing ability of Mineral Trioxide Aggregate (MTA) and root-end filling materials.

Material and Methods

The materials evaluated were: MTA, Calcium Silicate Cement with zirconium oxide (CSC/ZrO₂), and zinc oxide/eugenol (ZOE). Solubility test was performed according to ANSI/ADA. The difference between initial and final mass of the materials was analyzed after immersion in distilled water for 7 and 30 days. Retrograde cavities in human teeth with single straight root canal were performed by using ultrasonic tip CVD 9.5107-8. The cavities were filled with the evaluated materials to evaluate sealing ability using the bacterial leakage test with Enterococcus faecalis. Bacterial leakage was evaluated every 24 hours for six weeks observing the turbidity of Brain Heart infusion (BHI) medium in contact with root apex. Data were submitted to ANOVA followed by Tukey tests (solubility), and Kruskal-Wallis and Dunn tests (sealing ability) at a 5% significance level.

Results

For the 7-day period, ZOE presented highest solubility when compared with the other groups (p<0.05). For the 30-day period, no difference was observed among the materials. Lower bacterial leakage was observed for MTA and CSC/ZrO₂, and both presented better results than ZOE (p<0.05).

Conclusion

MTA and CSC/ZrO₂ presented better bacterial sealing capacity, which may be related to lower initial solubility observed for these materials in relation to ZOE.

In vitro and ex vivo microbial leakage assessment in endodontics: A literature review

The aim of this study was to perform a literature review of published in-vitro and ex-vivo studies, which evaluated microbial leakage in endodontics in the past 10 years. A comprehensive electronic literature search was carried out in PubMed database for English articles published from 2005 to 2016 using the keywords “endodontics,” “in vitro,” “ex vivo,” “microbial leakage,” “microbial penetration,” “saliva,” “Enterococcus faecalis,” “E. faecalis,” “endodontic sealers,” “temporary filling material,” “apical plug,” “mineral trioxide aggregate,” and “MTA.” The keywords were combined using Boolean operators AND/OR. Based on our search strategy, 33 relevant articles were included in the study. There are three main methods for assessment of bacterial microleakage, namely, (A) the dual-chamber leakage model, (B) detection of bacteria using a scanning electron microscope (SEM), and (C) polymerase chain reaction. All bacterial leakage models have some limitations and may yield different results compared to other microleakage evaluation techniques (i.e., dye penetration, fluid filtration, or electrochemical tests). The results of SEM correlated with those of microbial leakage test in most studies. Microbial leakage test using saliva better simulates the clinical setting for assessment of the leakage of single or mixed bacterial species.