Evaluation of Antibacterial Properties of Organic Gutta-percha Solvents and Synthetic Solvents Against Enterococcus faecalis

Effectiveness of H-files and Pro-Taper universal systems in removing Gutta-percha during endodontic retreatment: A comparative study

Objective

This research was aimed at assessing the effectiveness of manual H-files versus a combination of a Pro-Taper universal rotary canal preparation system and retreatment system in removing gutta-percha (GP) during endodontic retreatment, by using a digital radiography technique.

Methods

This ex vivo study used a non-probability consecutive sampling technique. The study sample comprised 60 extracted anterior permanent teeth, each with one root with a straight root canal (RC). After preparation, RCs were obturated with GP and sealer. Subsequently, teeth were stored for 2 weeks in a humid environment at 37 °C. Thirty teeth each were randomly assigned to the control (group I), and experimental (group II) groups. GP removal was performed with H-files {group I) or a combination of a Pro-Taper universal rotary canal preparation system and retreatment system (group 2). Digital radiographs were acquired with Carestream digital radiovisiography software (Kodak; version-VER.6.10.8.3-A), and the presence of residual GP was analyzed. AutoCAD (2006) software was used to demarcate the RC and residual root filling. The residual GP in both groups was compared with independent sample t-tests.

Results

The remaining root filling did not significantly differ when GP was removed with conventional Hedstrom files versus a combination of Pro-Taper Universal preparation and retreatment file systems. The residual GP was confined to the apical third of the canals in both groups.

Conclusions

Pro-Taper Universal preparation and retreatment file systems have similar effectiveness to manual H-files in GP removal in straight canals.

Functional characterization of helminth-associated Clostridiales reveals covariates of Treg differentiation

BACKGROUND

Parasitic helminths influence the composition of the gut microbiome. However, the microbiomes of individuals living in helminth-endemic regions are understudied. The Orang Asli, an indigenous population in Malaysia with high burdens of the helminth Trichuris trichiura, display microbiotas enriched in Clostridiales, an order of spore-forming obligate anaerobes with immunogenic properties. We previously isolated novel Clostridiales that were enriched in these individuals and found that a subset promoted the Trichuris life cycle. In this study, we aimed to further characterize the functional properties of these bacteria.

RESULTS

Clostridiales isolates were profiled for their ability to perform 57 enzymatic reactions and produce short-chain fatty acids (SCFAs) and hydrogen sulfide, revealing that these bacteria were capable of a range of activities associated with metabolism and host response. Consistent with this finding, monocolonization of mice with individual isolates identified bacteria that were potent inducers of regulatory T-cell (Treg) differentiation in the colon. Comparisons between variables revealed by these studies identified enzymatic properties correlated with Treg induction and Trichuris egg hatching.

CONCLUSION

We identified Clostridiales species that are sufficient to induce high levels of Tregs. We also identified a set of metabolic activities linked with Treg differentiation and Trichuris egg hatching mediated by these newly isolated bacteria. Altogether, this study provides functional insights into the microbiotas of individuals residing in a helminth-endemic region. Video Abstract.

Antimicrobial overproduction sustains intestinal inflammation by inhibiting Enterococcus colonization

Loss of antimicrobial proteins such as REG3 family members compromises the integrity of the intestinal barrier. Here, we demonstrate that overproduction of REG3 proteins can also be detrimental by reducing a protective species in the microbiota. Patients with inflammatory bowel disease (IBD) experiencing flares displayed heightened levels of secreted REG3 proteins that mediated depletion of Enterococcus faecium (Efm) from the gut microbiota. Efm inoculation of mice ameliorated intestinal inflammation through activation of the innate immune receptor NOD2, which was associated with the bacterial DL-endopeptidase SagA that generates NOD2-stimulating muropeptides. NOD2 activation in myeloid cells induced interleukin-1β (IL-1β) secretion to increase the proportion of IL-22-producing CD4+ T helper cells and innate lymphoid cells that promote tissue repair. Finally, Efm was unable to protect mice carrying a NOD2 gene variant commonly found in IBD patients. Our findings demonstrate that inflammation self-perpetuates by causing aberrant antimicrobial activity that disrupts symbiotic relationships with gut microbes.

Determination of Antifungal Effect of Natural Oil and Synthetic Gutta Percha Solvents Against Candida Albicans: A Disc Diffusion Assay

Introduction

The practice of removing root canal fillings with solvent materials is frequently required to help an irrigation solution enter the tubules. The current research was aimed at assessing the antifungal properties specifically the candida albicans of the various solvent materials used for the gutta-percha (GP) material.

Materials and Methods

Current research was aimed at as a lab method using the disk diffusion technique where the zone of inhibition (ZOI) was calculated. The materials that were analyzed were: orange oil, xylene, turpentine oil, chloroform, and eucalyptus oil. Candida albicans was the test organism employed in the investigation. The agar plates were covered with approximately 500 μL of the suspension. The sterile and empty disks were impregnated with 10 μL of pure GP solvents. These plates were incubated for one day at room temperature. The ZOI's mean diameters were calculated for all five materials and quantified each solvent's fungicidal activity. For intergroup comparison, ANOVA was utilized. P values < 0.05 were deemed substantial.

Results

The maximum inhibition exhibited by the Eucalyptus Oil it was 19.01 ± 1.02 mm. This was followed by Xylene. The other three solvents Chloroform, Orange Oil, and Turpentine Oil exhibited a similar ZOI. When all the solvents were compared there was a significant variance of P < 0.001. However, there were significant variances for the Eucalyptus Oil and the Xylene to all the other solvents P < 0.001.

Conclusion

This investigation showed that, in comparison to other solvents, the use of eucalyptus oil considerably reduced the levels of Candida Albicans.

Are Endodontic Solvents Cytotoxic? An In Vitro Study on Human Periodontal Ligament Stem Cells

The aim of this study was to assess the influence of eucalyptol, chloroform, and Endosolv on the proliferative capability, cell viability, and migration rates of human periodontal ligament stem cells (hPDLSCs) in vitro. Solvent eluates were formulated following ISO 10993-5 guidelines, and 1%, 0.25%, and 0.1% dilutions were prepared. The HPDLSCs were isolated from the extracted third molars of healthy donors. The following parameters were assessed: cell viability via trypan blue and IC50 assays, cell migration via horizontal wound healing assay, cell morphology via cell cytoskeleton staining (phalloidin labeling), and cell oxidative stress via reactive oxygen species assay. The data were analyzed using one-way ANOVA and Tukey’s posthoc tests, and their significance was established at p < 0.05. Chloroform and eucalyptol exhibited significantly higher cytotoxicity on the hPDLSCs in vitro compared to the control group, as shown by the cell viability, migration, morphology, and reactive oxygen species release assays. Alternatively, Endosolv showed adequate cytotoxicity levels comparable to those of the control group. The cytotoxicity of the tested endodontic solvents increased in a dose-dependent manner. The results from the present study highlight the cytotoxicity of chloroform and eucalyptol. Thus, their limited and cautious use is recommended, avoiding solvent extrusion.

Evaluation of the Antibacterial Effect of Xylene, Chloroform, Eucalyptol, and Orange Oil on Enterococcus faecalis in Nonsurgical Root Canal Retreatment: An Ex Vivo Study

Objectives

The present ex vivo study is aimed at evaluating the antibacterial efficacy of chloroform, eucalyptol, orange oil, and xylene against E. faecalis biofilm during nonsurgical root canal retreatment.

Materials and Methods

Eighty single-rooted teeth were instrumented. The samples were autoclaved, infected with E. faecalis for 4 weeks, and obturated with gutta-percha. Then the teeth were randomly assigned to 4 groups (n = 20): (1) chloroform, (2) eucalyptol, (3) orange oil, and (4) xylene. In all of the groups, gutta-percha removal was conducted according to the same protocol although the solvent used in each group was different. Bacterial samples were collected after gutta-percha removal and following additional apical enlargement. Intergroup and intragroup analyses were conducted using one-way ANOVA combined with the post hoc Tukey test and the paired-sample t-test, respectively. Statistical significance was set to 0.05.

Results

All of the groups showed more than 99% bacterial load reduction. The least bacterial load after gutta-percha removal was observed in the chloroform group (p < 0.001). The orange oil group showed a significantly lower bacterial load compared to the eucalyptol group (p = 0.001), while it was not different from the xylene group (p = 0.953). The xylene group also had a significantly lower bacterial load compared with the eucalyptol group (p = 0.017). After apical enlargement, the chloroform group had a significantly lower bacterial load compared to the other groups. The comparison of bacterial load values before and after apical enlargement in the chloroform and eucalyptol groups showed a statistically significant difference (p_choloroform = 0.011, p_eucalyptol = 0.001).

Conclusion

Chloroform was the most effective solvent in terms of antimicrobial activity against E. faecalis followed by orange oil and xylene, which were not significantly different though, and eucalyptol. All of the solvents showed more than 99% bacterial load reduction. Chloroform and xylene revealed to be associated with favorable antibiofilm activity among the examined solvents.