Structural effects of sodium hypochlorite solutions on gutta-percha cones: atomic force microscopy study

The Antimicrobial Efficacy of Sodium Hypochlorite and Chlorhexidine in Gutta-Percha Cone Decontamination: A Systematic Review

This systematic review aims to compare the efficacy of sodium hypochlorite (NaOCl) and chlorhexidine digluconate (CHX) in decontaminating gutta-percha (GP) cones against endodontic pathogens-Enterococcus faecalis (E. faecalis), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans)-within 0-10 min. A systematic search was conducted in six databases (PubMed, Web of Science, Cochrane Library, SCIELO, Scopus, and LILACS), supplemented by manual searches performed independently by three reviewers. No publication year restrictions were applied, and only English-language studies were included. This review followed the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The risk of bias was assessed using six parameters with a modified Cochrane risk of bias tool. Out of 309 potentially eligible studies, 216 were screened by title and abstract, 32 were selected for full-text assessments, and 7 were included. All studies had a moderate or high risk of bias. The majority of the included studies showed that higher NaOCl concentrations effectively eliminate E. faecalis and S. aureus within 1-5 min. However, data on CHX's antimicrobial effect on C. albicans were limited. The qualitative analysis suggests that NaOCl remains the most effective agent for GP decontamination, while CHX with additives shows potential against fungal species.

Influence of disinfecting solutions on the surface topography of gutta-percha cones: a systematic review of in vitro studies

The surface integrity of gutta-percha cones is a crucial factor in the success of endodontic procedures. Disinfecting solutions play a pivotal role in sterilizing gutta-percha cones, but their influence on gutta-percha surface topography remains a subject of concern. This systematic review aimed to present a qualitative synthesis of available laboratory studies assessing the influence of disinfecting solutions on the surface topography of gutta-percha and offers insights into the implications for clinical practice. The present review followed PRISMA 2020 guidelines. An advanced database search was performed in PubMed, Google Scholar, Embase, Scopus, LILAC, non-indexed citations and reference lists of eligible studies in May 2024. Laboratory studies, in English language, were considered for inclusion. The quality (risk of bias) of the included studies was assessed using parameters for in vitro studies. A total of 28 studies were included in the qualitative synthesis. Based on the included in vitro studies, surface deposits and alterations in the physical properties of gutta-percha cones were observed after the disinfection protocol. A comprehensive review of the available literature indicates that the choice of disinfecting solution, its concentration, and immersion time significantly affect the surface topography of gutta-percha cones.

Effect of various disinfectant solutions on the tensile strength of gutta-percha using the rapid sterilization technique

Context

Gutta-percha (GP) gets contaminated during handling. It becomes imperative to ensure GP is sterile before placement in root canal space.

Aims

The aim of the study was to evaluate and compare the tensile strength of GP treated with four different disinfectant solutions: 3% sodium hypochlorite (NaOCl), amla juice (AJ), Aloe vera (AV) juice, and pancha tulsi (PT).

Settings and Design

The study design was an in vitro study.

Materials and Methods

Fifty GP cones with a size of 30 were procured from sealed packages in five different groups. Experimental groups were disinfected for 1 min with 3% NaOCl, AJ, AV, and PT except the control group. Tensile and Brinell Testing Machine is used to measure the tensile strengths of GP.

Statistical Analysis Used

Results were subjected to statistical analysis using the Kruskal-Wallis test followed by Dunn's post hoc test.

Results

The mean tensile strength values for Groups A, B, C, D, and E are 9.49 Mpa, 13.33 Mpa, 12.58 Mpa, 12.69 MPa, and 13.56 MPa, respectively. In the herbal disinfectant group, such as AJ, AV, and PT, the tensile strength was not significantly altered, whereas in the 3% NaOCl group, it was reduced considerably.

Conclusions

AJ, AV juice, and PT as a GP disinfectant do not alter the tensile strength of GP cones.

Evaluation of the efficacy of a novel disinfecting material on the surface topography of gutta-percha: An in vitro study

Context

The effect of chemical disinfection on gutta-percha (GP) has to be closely studied whether it affects surface topography and thereby causes leakage and reinfection of canals.

Aims

The purpose of the study is to assess the surface topography of GP cones after disinfecting with a novel disinfecting material, graphene oxide (GO), and compare the same with other disinfecting materials, including sodium hypochlorite (NaOCl) and silver nanoparticles (AgNps).

Settings and Design

After determining the power (0.84) of the study, 48 GP cones were taken and categorized into four different groups based on disinfecting agents.

Materials and Methods

Forty-eight GP cones (ISO size 30 6% taper, DIADENT) were taken and are randomly selected and grouped as follows according to the disinfecting agents: Group 1 - control (untreated GP points, n = 12), Group 2 - NaOCl (n = 12), Group 3 - AgNPs (n = 12), and Group 4 - GO (n = 12), respectively. After treating with the above disinfecting materials, the surface topography of samples was evaluated using atomic force microscopy. The data were analyzed statistically using one-way ANOVA and post hoc (Tukey's honestly significant difference) tests.

Statistical Analysis Used

IBM SPSS (version 21.0) software was used. The tests performed were one-way ANOVA and post hoc. Statistically, significance was set at a P ≤ 0.05.

Results

The root means square values and surface roughness values were lesser for the GO group and AgNPs when compared with the NaOCl group, which were statistically significant.

Conclusions

Within the limitations of the study, this study had shown lesser surface topography deterioration of GP cones when treated with GO and AgNPs, whereas more deterioration was observed with NaOCl.

Alkaline conditions can affect the volume and chemical characteristics of dental gutta-percha

The effects of alkaline pH on the size and surface characteristics of gutta-percha were studied. Forty ProTaper Universal-F2 gutta-percha cones (GPC) were stored individually for 8-weeks. GPC were distributed into 2 groups (n = 20) based on the storage solutions' pH (pH7, pH12). The GPC volume was measured after 1,2,3,4 and 8-weeks using water displacement method and compared to the baseline volume. The surfaces of representative GPCs were analysed using Raman spectroscopy and assessed later using Scanning Electron Microscopy with Energy-Dispersive X-Ray Spectroscopy (EDS). Samples t test was used to compare the change in volume of GPC and a repeated measures Analysis of Variance (ANOVA) was used to compare the effects of storage durations. After 8-weeks, GPCs aged in high-pH exhibited significant drop in their volume (16%) compared with GPCs aged in water (2.5%). The surface of GPCs stored in water or high-pH both demonstrated structural and chemical alterations in comparison with non-aged GPCs.

Calcium Silicate-Based Root Canal Sealers: A Narrative Review and Clinical Perspectives

Over the last two decades, calcium silicate-based materials have grown in popularity. As root canal sealers, these formulations have been extensively investigated and compared with conventional sealers, such as zinc oxide-eugenol and epoxy resin-based sealers, in in vitro studies that showed their promising properties, especially their biocompatibility, antimicrobial properties, and certain bioactivity. However, the consequence of their higher solubility is a matter of debate and still needs to be clarified, because it may affect their long-term sealing ability. Unlike conventional sealers, those sealers are hydraulic, and their setting is conditioned by the presence of humidity. Current evidence reveals that the properties of calcium silicate-based sealers vary depending on their formulation. To date, only a few short-term investigations addressed the clinical outcome of calcium silicate-based root canal sealers. Their use has been showed to be mainly based on practitioners' clinical habits rather than manufacturers' recommendations or available evidence. However, their particular behavior implies modifications of the clinical protocol used for conventional sealers. This narrative review aimed to discuss the properties of calcium silicate-based sealers and their clinical implications, and to propose rational indications for these sealers based on the current knowledge.

Management of Instrument Sterilization Workflow in Endodontics: A Systematic Review and Meta-Analysis

Endodontic treatment consists of different working procedures, such as the isolation of the operating field, pulp chamber access, and cleaning and shaping phases with at last the need of a three-dimensional filling of the canals. Each step requires a series of single-use or sterilizable instruments. We have performed a systematic review of different sterilization and disinfection procedures aiming at drawing up a disinfection and sterilization procedure to be used on endodontic instruments. A search on PubMed and Scopus was carried out using the following keywords: “endodontic sterilization,” “endodontic autoclave,” “decontamination dental bur,” “sterilization dental burs,” and “gutta-percha points sterilization.” Eligible articles were included in the qualitative and quantitative analysis. Results of the meta-analysis showed that the most effective method in sterilization is autoclaving. The qualitative analysis showed that the use of single-use or first-use instruments requires presterilization or sterilization procedures, and for reusable tools, attention must be paid to the removal of debris deposited on the blades, not easy to remove manually.

Comparative Evaluation of Three Herbal Solutions on the Disinfection of Guttapercha Cones: An In vitro Study

INTRODUCTION

Guttapercha (GP) cones are usually supplied in aseptic, sealed packages from the manufacturers, but once exposed to the dental office environment or even by handling; they can be contaminated by a number of microorganisms. Supplementary decontamination of GP cones is critical. As they cannot be sterilized by moist or dry heat, cold sterilization, using disinfectants should be used.

AIM

The aim of the study was to evaluate rapid, reliable, convenient and effective method of disinfection of GP cones using readily available herbal solutions such as Aloevera Juice, Amla Juice and Pancha Tulsi.

MATERIALS AND METHODS

Ninety GP cones were selected for the study. Based on the contaminants used, 80 GP cones were divided into two groups: Group A and Group B with 40 cones in each group and the remaining 10 cones which were uncontaminated served as negative control. The cones from Group A were contaminated with Staphylococcus aureus (S. aureus) and Group B were contaminated with Enterococcus faecalis (E. faecalis). The contaminated cones from both groups were subdivided into four groups with 10 cones in each group. Group I cones were disinfected with Aloevera Juice, Group II with Amla Juice and Group III with Pancha Tulsi. The fourth group consisted of GP cones without any disinfection which served as positive control. All the cones were then incubated in thioglycollate media for seven days. The thioglycollate media was subcultured and colony forming units were counted. The data were analyzed by one way ANOVA (analysis of variance) and Post-hoc Tukey test using SPSS 17.0 software.

RESULTS

Mean colony forming units were compared in all the groups and there was a statistically significant difference present among the groups (p<0.01). Pancha Tulsi was found to be most effective disinfectant followed by Amla Juice.

CONCLUSION

All the herbal solutions were found to be effective in the disinfection of GP points. However, Pancha Tulsi possesses superior antibacterial activity when compared with Aloevera Juice and Amla juice.

Comparative evaluation of tensile strength of Gutta-percha cones with a herbal disinfectant

Aim:

To evaluate and compare the tensile strength values and influence of taper on the tensile strength of Gutta-percha (GP) cones after disinfection with sodium hypochlorite (SH) and Aloe vera gel (AV).

Materials and Methods:

Sixty GP cones of size 110, 2% taper, 60 GP cones F3 ProTaper, and 60 GP of size 30, 6% taper were obtained from sealed packs as three different groups. Experimental groups were disinfected with 5.25% SH and 90% AV gel except the control group. Tensile strengths of GP were measured using the universal testing machine.

Results:

The mean tensile strength values for Group IA, IIA and IIIA are 11.8 MPa, 8.69 MPa, and 9.24 MPa, respectively. Results were subjected to statistical analysis one-way analysis of variance test and Tukey post-hoc test. 5.25% SH solutions decreased the tensile strength of GP cones whereas with 90% AV gel it was not significantly altered.

Conclusion:

Ninety percent Aloe vera gel as a disinfectant does not alter the tensile strength of GP cones

Biofilm forming capacity of Enterococcus faecalis on Gutta-percha points treated with four disinfectants using confocal scanning laser microscope: An in vitro study

Background:

The aim of this study was to evaluate and compare the in vitro biofilm forming capacity of Enterococcus faecalis on Gutta-percha points disinfected with four disinfectants.

Materials and Methods:

A total of 50 Gutta-percha points used in this study were divided into four test groups based on disinfectant (5.25% sodium hypochlorite, 2% chlorhexidine gluconate, 20% neem, 13% benzalkonium chloride [BAK]), and one control group. The Gutta-percha points were initially treated with corresponding disinfectants followed by anaerobic incubation in Brain Heart Infusion broth suspended with human serum and E. faecalis strain for 14 days. After incubation, these Gutta-percha points were stained with Acridine Orange (Sigma – Aldrich Co., St. Louis, MO, USA) and 0.5 mm thick cross section samples were prepared. The biofilm thickness of E. faecalis was analyzed quantitatively using a confocal scanning laser microscope. Results statistically analyzed using analysis of variance. P < 0.05 was considered to be significant.

Results:

Confocal scanning laser microscope showed reduced amount of E. faecalis biofilm on Gutta-percha points treated with BAK and sodium hypochlorite. Post-hoc (least square differences) test revealed that there is no statistically significant difference between BAK and sodium hypochlorite groups (P > 0.05).

Conclusion:

This study illustrates that the Gutta-percha points disinfected with sodium hypochlorite and BAK showed minimal biofilm growth on its surface.

Antimicrobial and structural effects of different irrigation solutions on gutta-percha cones

Purpose:

To evaluate the alterations on the surface of gutta-percha cones (GPCs) on exposure to the different irrigation solutions and their possible antibacterial effect against Enterococcus faecalis. (E. faecalis)

Materials and Methods:

Disinfection ability of different solutions (5.25% sodium hypochlorite, 2% chlorhexidine, 1% peracetic acid, and QMix) were tested with 96 GPCs and the time of exposure to each solution was 5 and 10 minutes, respectively. GPCs used in this study were contaminated with E.faecalis. After disinfection, GPCs were placed in tubes containing the medium and incubated at 37˚C for 7 days. All tubes were visually checked for turbidity at 24-hour intervals. About 92 new GPCs were analyzed by means of SEM/EDS to assess the topography and chemical elements present on their surface. The data generated was analyzed using Pearson chi-square test, p<0.05.

Results:

There were no significant statistical differences in disinfection quality between the irrigation solutions used on GPCs contaminated with E. faecalis (p>0.05). SEM/EDS analyses showed no alteration in the superficial features of GPCs after treating with various irrigation solutions.

Conclusion:

QMix was found to be an effective agent for rapid disinfection of GPCs as well-known irrigation solutions. Irrigation solutions were found to have sterilized the GPCs after both 5 and 10 minutes of exposure.

A comparative evaluation of the effect of 5.25% sodium hypochlorite and 2% chlorhexidine on the surface texture of Gutta-percha and resilon cones using atomic force microscope

Aims & Objectives:

The purpose of this study was to investigate the effects of 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) on Gutta-percha and Resilon cones using an atomic force microscope (AFM).

Materials and Methods:

Gutta-percha cones (n = 15) and Resilon cones (n = 15) were cut 3 mm from their tip, attached to a glass slide with cyanoacrylate glue and immersed in 5.25% NaOCl and CHX for 1, 5, 10, 20 and 30 min. Five each of Gutta-percha and Resilon cones not treated with any disinfectant were used as control. The analysis of the surface topography was performed on the region between 1 and 2 mm from the tip using the AFM. The root mean square (RMS) parameters for contact mode imaging were measured. The differences between RMS values were tested by SPSS-16.0 version statistical software [IBM SPSS (Statistical Product and Service Solutions) Data Software, Chicago, US] using Kruskal-Wallis ANOVA, Mann-Whitney U-test and Wilcoxon matched pairs test.

Results:

There was no deterioration in the surfac e topography of Gutta-percha and Resilon when treated with 2% CHX in comparison to baseline (P < 0.05). Resilon exhibited no deterioration in topography when immersed in 5.25% NaOCl. There was a significant decrease in the mean RMS values of Gutta-percha treated with NaOCl from the control at time intervals of 1, 5, 10, 20 and 30 min.

Interaction between chlorhexidine-impregnated gutta-percha points and several chlorine-containing endodontic irrigating solutions

AIM

To evaluate if the immersion of chlorhexidine-impregnated gutta-percha points in chlorine-containing endodontic irrigants causes colour changes and precipitate formation.

METHODOLOGY

Eighty-one size 25 chlorhexidine medicated (Activ Points, Roeko, Langenau, Germany) and 27 size 25 standard gutta-percha points (Roeko) were immersed in microtubes, containing the following solutions: 0.5 and 5.25% NaOCl or Aquatine (Optident, Ilkley, UK). The samples were visually assessed, by two independent observers, at regular intervals over 3 weeks, to detect colour changes and precipitate formation. A score system was used to grade the precipitate intensity. To compare the number of days required for a precipitate to form mean and standard differences were calculated; the means between the groups were compared using a one-way analysis of variance test. Mean intensity scores were calculated and compared between groups using Kruskal-Wallis procedure followed by the Mann-Whitney test.

RESULTS

The groups containing 5.25% NaOCl started to produce a visible precipitate after fourteen days (16.48 ± 0.98) for the Activ points; this process was first noticed with the standard gutta-percha group on day 17 (18.33 ± 1.22 days), with a statistically significant difference (P = 0.002). When looking at the intensity scores from day 17 onwards, these two groups differed statistically, with a greater amount for the AP group (P < 0.001). No other test group presented with changes.

CONCLUSION

The placement of impregnated gutta-percha points, in 5.25% NaOCl for a 2-week period, caused the formation of a precipitate in the experimental conditions of this study.

Effects of Sodium Hypochlorite and Chlorhexidine Solutions on Resilon (Synthetic Polymer Based Root Canal Filling Material) Cones: An Atomic Force Microscopy Study

The aim of the present study is to evaluate the effects of 2% chlorhexidine and 5.25% sodium hypochlorite on the surface properties of Resilon cones with the atomic force microscopy. The Resilon cones were immersed in disinfecting agents (5.25% sodium hypochlorite and 2% chlorhexidine) at 1 and 5 min time intervals. Atomic force microscopy was used to evaluate topographical deviations of Resilon cones. Root mean square (RMS) parameters for topographic amplitudes were calculated. The cones exhibited statistically significant low RMS values at 5-min immersion in sodium hypochlorite and chlorhexidine groups compared to the all other groups (p < 0.05). One-minute immersion did not show any significant deterioration on the Resilon surface (p > 0.05). In conclusion, sodium hypochlorite and chlorhexidine solutions used for disinfection significantly decreased (p < 0.05) the RMS values of Resilon cones at 5-min applications.