Antibacterial effect of different concentrations of sodium hypochlorite on Enterococcus faecalis biofilms in root canals

Antimicrobial effectiveness of ultrasonic irrigation in root canal treatment: a systematic review of randomized clinical trials and meta-analysis

OBJECTIVE

The objective of this systematic review and meta-analysis (SRM) was to answer the question as to whether the use of ultrasonic irrigation (UI) results in better antimicrobial activity in root canal disinfection compared to conventional irrigation (CI).

METHODS

A literature search was performed in the main scientific databases, carried out until October 2021. The eligibility criteria were randomized clinical trials (RCTs). Two meta-analyses were conducted using R software with the "META" package. The mean difference (MD) and odds ratio (OR) measure of effect were calculated. The fixed effect model was applied with a 95% confidence interval. The Cochrane collaboration scale was used to assess risk of bias and the GRADE tool to assess the quality of evidence.

RESULTS

A total of 1782 records were screened, and 12 studies meeting the criteria were included in this review. A low risk of bias was observed for most domains, except allocation concealment that was considered unclear. The certainty of evidence was classified as moderate in the OR meta-analyses and low in the MD meta-analyses. Ultrasonic irrigation resulted in a better antimicrobial effect in both meta-analyses, MD 1.42 [1.60; 1.23] p < 0.0001, I² = 80%; and OR 3.86 [1.98; 7.53] p< 0.0001, I² = 28.7%.

CONCLUSION

Within the limitations of this SRM, UI presented better antimicrobial efficacy than CI.

CLINICAL RELEVANCE

UI should be used by clinicians as it promotes better antimicrobial efficacy in patients undergoing endodontic treatment.

Advances in the Role of Sodium Hypochlorite Irrigant in Chemical Preparation of Root Canal Treatment

Irrigation of root canal system is of great significance to the success of endodontic treatment, where sodium hypochlorite (NaOCl) is the most widely used irrigant in chemical preparation. NaOCl functions by eliminating bacterial biofilms and dissolving organic tissue, which may vary according to several factors such as the microbiology of root canal infection and the concentration of the irrigant. It has been proposed that the effectiveness of NaOCl could be enhanced via several methods, including heating the irrigant, applying in conjunction with certain reagents, or activating by agitation techniques. Despite its antibacterial and tissue-dissolving capacities, NaOCl should be used with caution to avoid detrimental effect due to its cytotoxicity and negative effect on dentin properties. In this narrative review, we discussed the factors that affect the properties of NaOCl, the methods to improve its efficacy, and the side effects that might occur in clinical practice.

Use of electromagnetic stimulation on an Enterococcus faecalis biofilm on root canal treated teeth in vitro

Root canal disinfection is of utmost importance in the success of the treatment, thus, a novel method for achieving root canal disinfection by electromagnetic waves, creating a synergistic reaction via electric and thermal energy, was created. To study electromagnetic stimulation (EMS) for the disinfection of root canal in vitro, single rooted teeth were instrumented with a 45.05 Wave One Gold reciprocating file. Specimens were sterilized and inoculated with Enterococcus faecalis ATCC 29,212, which grew for 15 days to form an established biofilm. Samples were treated with 6% sodium hypochlorite (NaOCl), 1.5% NaOCl 1.5% NaOCl with EMS, 0.9% saline with EMS or 0.9% saline. After treatments, the colony forming units (CFU) was determined. Data was analyzed by Wilcoxon Rank Sums Test (α = 0.05). One sample per group was scored and split for confocal laser scanning microscopy imaging. There was a significant effect with the use of NaOCl with or without EMS versus 0.9% saline with or without EMS (p = 0.012 and 0.003, respectively). CFUs were lower when using 0.9% saline with EMS versus 0.9% saline alone (p = 0.002). Confocal imaging confirmed CFU findings. EMS with saline has an antibiofilm effect against E. faecalis and can potentially be applied for endodontic disinfection.

Antibacterial Properties of Aloe vera on Intracanal Medicaments against Enterococcus faecalis Biofilm at Different Stages of Development

Background

Use of herbal compounds as an intracanal medicament in the field of endodontics has become noteworthy, one of which is the Aloe vera compound whose antibacterial effect has already been proven in the planktonic form of Enterococcus faecalis. The purpose of this study is to evaluate the antibacterial effect of Aloe vera on E. faecalis biofilms at the 4^th and 6^th week of development.

Materials and Methods

130 single root canal teeth without anomalies and caries were used. They were divided into two groups of 65 teeth for four and six weeks of biofilm production. Five samples of each group were examined for confirmation of biofilm formation under an electron microscope. Study groups were investigated with an antimicrobial agent as an intracanal medicament including 20 samples treated with Aloe vera, calcium hydroxide, and phosphate-buffered saline, and biofilm and survival of pathogens were investigated. Dentin chip suspensions were used for colony-forming unit (CFU) counting to estimate remaining E. faecalis counts.

Results

The CFU mean in the 4^th week subgroup in Aloe vera, phosphate-buffered saline, and calcium hydroxide was 0, 69166.66 ± 31688.58, and 25000 ± 30822.07, and in the 6^th week, it was 136.36 ± 323.33, 95000 ± 12247.44, and 27501.66 ± 36570.34, respectively, which showed a significant difference between the used materials (p < 0.05).

Conclusion

Aloe vera, in contrast to calcium hydroxide, eliminated 4^th and 6^th week biofilms and showed remarkable antibacterial properties against E. faecalis biofilm. These results support potency of Aloe vera to use as a natural antimicrobial material in the intracanal medicament.

Passive Ultrasonic Irrigation Efficacy in the Vapor Lock Removal: Systematic Review and Meta-Analysis

Passive Ultrasonic Irrigation (PUI) represents one of the most used systems to improve the endodontic irrigants activity. PUI acts increasing the reaction rate of NaOCl, with an increase of dentinal debris and smear layer removal. There is a stronger shear stress and a vapor lock reduction. Aim of this systematic review was to figure out the effects of the PUI on the vapor lock removal, during irrigation. Literature research has been carried out by two reviewers, consulting online databases such as PubMed, EBSCO, and Google Scholar, using keywords like Vapor Lock, Vapour Lock, and Vapor Lock Endodontic. The articles list has been screened based on titles and abstracts, applying eligibility and inclusion criteria. The three articles were eligible for quantitative and statistical analysis, by using RevManager Software Version 5.3. Results show statistical heterogeneity (P=0.08; I² index=61%) in the vapor lock elimination between the use of PUI and PPI, with an overall Odds Ratio=0.08, CI=95% [0.03;0.25]. PUI resulted to be a useful technique to improve NaOCl activity for vapor lock removal, despite PPI alone using a needle.

Comparative evaluation of efficacy of 0.2% sodium hypochlorite (Hi Wash) mouthwash with 0.2% chlorhexidine mouthwash on plaque-induced gingivitis: A clinical trial

Background:

Bleeding gums are one of the common complaints to visit a dentist. Mechanical removal of plaque alone is not sufficient for the reduction of gingival inflammation associated with plaque. Mouthwashes are supplemented to it as a homecare product. The objective of this study is to evaluate the efficacy of 0.2% sodium hypochlorite mouthwash on plaque and gingival inflammation and to assess the clinical parameters of gingivitis patients from baseline to 21 days with the use of 0.2% sodium hypochlorite and 0.2% chlorhexidine mouthwashes.

Materials and Methods:

This clinical trial study included 60 patients with gingival inflammation evaluated using clinical parameters such as bleeding on probing index, plaque index, and gingival index at baseline and 21 days. Group A patients were given Hi Wash mouthwash and Group B 0.2% chlorhexidine mouthwash with 30 patients in each group.

Results:

The scores for clinical parameters were significantly reduced after 21 days in Group A and Group B patients, and there was a reduction in plaque-associated gingival inflammation without scaling and root planning.

Conclusions:

0.2% sodium hypochlorite mouthwash is as effective as 0.2% chlorhexidine for the treatment of gingivitis as it is an adjunct to mechanical plaque removal in terms of safety, less side effects, less staining and can be used as a routine mouthwash.

Comparison of the permeability rate of nanoparticle calcium hydroxide and conventional calcium hydroxide using a fluorescence microscope

BACKGROUND

The permeability feature of conventional calcium hydroxide (CH) and nanoparticle CH (NCH) was compared to show the desired effects of this new material and in case of confirmation of its other properties; CH can be used as a safe alternative.

MATERIALS AND METHODS

This in vitro was carried out in two phases: First phase: measurement and comparison of the permeability rate of conventional CH and NCH in the dentinal tubules employing a fluorescence microscope were carried out. Second phase: measurement and comparison of the permeability rate of NCH and conventional CH in L929 fibroblast cells using a fluorescence microscope were carried out. Kruskal-Wallis analysis was used for overall comparisons. A series of Mann-Whitney U tests were used for pair-wise comparisons (P < 0.05).

RESULTS

Based on the results of Kruskal-Wallis test, in all three regions of the cervical third, middle third, and apical third of the root, mean values of the percentage difference of the fluorescence and color change in NCH were more than the conventional CH, and the difference was statistically significant (P < 0.001). the percentage of fluorescence color change in drug with the concentration of 1 g/cc was more than the one with the concentration of 0.1 g/cc and the difference was statistically significant (P < 0.001).

CONCLUSION

The nanoparticle drug compared with the conventional drug has a more penetration depth in all regions of the root of the dentinal tubules.