Evaluation of antibacterial efficacy of Chitosan, Chlorhexidine, Propolis and Sodium hypochlorite on Enterococcus faecalis biofilm : An in vitro study

The effect of the enzymes trypsin and DNase I on the antimicrobial efficiency of root canal irrigation solutions

The purpose of this study was to evaluate the antibacterial efficacy of using 2.5% NaOCl, 2% chlorhexidine (CHX), Irritrol, and chitosan-coated silver nanoparticles (AgCNPs) alone or in combination with deoxyribonuclease I (DNase I) and trypsin pre-enzyme applications in dentin samples contaminated with Enterococcus faecalis (E. faecalis) by CLSM. 144 dentin blocks with confirmed E. faecalis biofilm formation were divided randomly according to the irrigation protocol (n = 12): NaOCl, CHX, Irritrol, AgCNPs, trypsin before NaOCl, CHX, Irritrol, AgCNPs, and DNase I before NaOCl, CHX, Irritrol, AgCNPs. Dentin blocks were stained with the Live/Dead BacLight Bacterial Viability Kit and viewed with CLSM after irrigation applications. The percentage of dead and viable bacteria was calculated using ImageJ software on CLSM images. At a significance level of p < 0.05, the obtained data were analyzed using one-way Anova and post-hoc Tukey tests. In comparison with NaOCl, CHX had a higher percentage of dead bacteria, both when no pre-enzyme was applied and when DNase I was applied as a pre-enzyme (p < 0.05). There was no difference in the percentage of dead bacteria between the irrigation solutions when trypsin was applied as a pre-enzyme (p > 0.05). AgCNPs showed a higher percentage of dead bacteria when trypsin was applied as a pre-enzyme compared to other irrigation solutions (p < 0.05), while the pre-enzyme application did not affect the percentage of dead bacteria in NaOCl, CHX, and Irritrol (p > 0.05). No irrigation protocol tested was able to eliminate the E. faecalis biofilm. While the application of trypsin as a pre-enzyme improved the antimicrobial effect of AgCNPs, it did not make any difference over other irrigation solutions.

Evaluation of the Anti-microbial Efficacy of a Novel Endodontic Irrigant Against Enterococcus faecalis: An In Vitro Study

INTRODUCTION

Enterococcus faecalis is a constant microbiome that plays an inevitable role in the etiology of peri radicular lesions after endodontic treatment, chronic and, apical periodontitis and, recently, in periimplantitis. The effective biomechanical preparation and the use of potent irrigating solutions will permit bacterial neutralization and toxin inactivation, leading to the success of endodontic treatment. This study aimed to evaluate the "anti-microbial" efficacy of simvastatin (SMV) against E. faecalis as an endodontic irrigant.

MATERIALS AND METHODS

In this invitro experimental study, the antimicrobial efficacy of SMV was evaluated against E. faecalis using the agar diffusion method. The samples were divided randomly into the following groups. GROUP 1: SMV solution 1 μM/L concentration, GROUP 2: SMV solution 5 μM/L concentration, GROUP 3: SMV solution 10 μM/L concentration, GROUP 4: 2% chlorhexidine gluconate (CHX) solution (positive control), and GROUP 5: normal saline (negative control). Linear measurement was done by measuring the zones of inhibition around the medicaments in the cavities in millimeters. Results were tabulated.

RESULTS

The results of the study have shown the zone of inhibition of Group 4 (2% CHX solution) is 19 mm, which demonstrated the best outcome. When comparing the test samples, Group 3 (SMV solution 10 M/L concentration) has the best zone of inhibition, measuring 14 mm, followed by Group 2 (SMV solution 5 M/L concentration), which is 9 mm.

CONCLUSION

The results of this in vitro study have proven that SMV's anti-microbial activity, albeit less potent than CHX in this in vitro investigation, has demonstrated that it can be utilized as an efficient endodontic irrigant.

Antibiofilm activity of ultrasonic and diode laser activated sodium hypochlorite, chitosan, and chlorhexidine: A confocal laser scanning microscopic in vitro study

Aim

The aim of this study was to assess and compare the effect of ultrasonic and diode laser-activated sodium hypochlorite (NaOCl), chitosan, and chlorhexidine (CHX) on the removal of Enterococcus faecalis biofilm adherent to the root canal using a confocal laser scanning microscope (CLSM).

Materials and Methods

Root canals in 112 single-rooted teeth were instrumented using a rotary Ni-Ti system. Biofilms of E. faecalis were generated based on an established protocol. Samples were randomly divided into three experimental (n = 28) and one control (n = 28) group based on the irrigation protocol employed and the three experimental groups were further subdivided into subgroups based on the activation protocol (subgroup A - ultrasonic activated and subgroup B - diode laser activated). The groups were Group 1 (control), Group 2 (3% NaOCl for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation), Group 3 (2% CHX for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation), and Group 4 (0.2% chitosan for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation. Confocal laser scanning microscopy was used to assess bacterial viability in situ. Data were analyzed by appropriate statistical analyses with P = 0.05.

Results

All experimental irrigation protocols destroyed the biofilm in the root canal lumen. Within the dentinal tubules, all groups had a significantly higher percentage of dead bacteria than the saline control (P < 0.05). There was no significant difference between CHX activated with ultrasonics, CHX activated with a diode laser, chitosan activated with ultrasonics and chitosan activated with diode laser groups (P > 0.05), whereas NaOCl ultra and NaOCl diode groups brought about more bacterial reduction than other groups (P < 0.05). The mean effectiveness and the bacterial kill ability were seen highest for the NaOCl activated with the ultrasonics group. There was no significant difference between diode laser activation and ultrasonic activation in CHX activated with ultrasonics, CHX activated with a diode laser, chitosan activated with ultrasonics and chitosan activated with diode laser groups (P > 0.05), but there was a significant difference between diode laser and ultrasonic activation in NaOCl group. Ultrasonic activation of the NaOCl was more effective than diode activation in reducing E. feacalis biofilms (P < 0.05).

Conclusions

The use of NaOCl with the activation by ultrasonics caused the greatest reduction of E. faecalis. Ultrasonic activation was found superior to diode laser activation in dentinal tubule disinfection.

Antimicrobial efficacy of composite irrigation solution against dominant pathogens in seawater immersion wound and in vivo wound healing assessment

Seawater immersion wound is inevitably accompanied by bacterial infection. Effective irrigation is critical for bacterial infection prevention and wound healing. In this study, the antimicrobial efficacy of a designed composite irrigation solution against several dominant pathogens in seawater immersion wounds was evaluated, and in vivo wound healing assessment was conducted in a rat model. According to the time-kill result, the composite irrigation solution exhibits excellent and rapid bactericidal effect against Vibrio alginolyticus and Vibrio parahaemolyticus within 30 s of treatment while eliminating Candida albicans, Pseudomonas aeruginosa, Escherichia coli, and the mixed microbes after 1 h, 2 h, 6 h, and 12 h of treatment, respectively. Significant bacterial count reduction of Staphylococcus aureus was observed after 5 h treatment. In addition to its skin non-irritating attribute, the in vivo wound healing results further demonstrated that the irrigation solution showed high repair efficiency in the skin defect model inoculated with the mixed microbes. The wound healing rate was significantly higher than that of the control and normal saline groups. It could also effectively reduce the number of viable bacteria on the wound surface. The histological staining indicated that the irrigation solution could reduce inflammatory cells and promote collagen fibers and angiogenesis, thereby promoting wound healing. We believed that the designed composite irrigation solution has great potential for application in the treatment of seawater immersion wounds.

Evaluation of antibacterial effects of different intracanal medicaments on Enterococcus faecalis in primary teeth: An in vitro study

OBJECTIVES

Successful endodontic therapy is based on the reduction of infecting bacteria by cleaning, shaping, and disinfecting of the root canal system, thus the use of intracanal dressing is necessary for optimal success of root canal treatment. This study was designed to evaluate the effect of chitosan and propolis as intracanal medicaments against Enterococcus faecalis compared to calcium hydroxide in primary root canals.

MATERIAL AND METHODS

Ninety-six extracted primary second molars were collected. Teeth preparation was completed to size 30 K-file. They were randomly divided into four groups; (A): chitosan, (B): propolis, (C): calcium hydroxide, and (D): control group (saline). The tooth specimens were inoculated with E. faecalis. Then, tested materials were applied for all groups in accordance to the groups each tooth belonged to. Following this, the bacterial colonies were counted after 24 h, 72 h, and 1 week of applying dressing materials and incubation. Finally, one-way analysis of variance and Fisher's least significant difference tests were used for statistical comparisons between the groups at a significance level of .05.

RESULTS

No statistically significant difference was found between groups A, B, and C for both 24 h and a week (p ≥ .05). Yet, a statistical difference between groups A, B, C, and D after 72 h and 1 week were seen (p ≤ .05).

CONCLUSIONS

Chitosan and propolis medicaments were as effective as calcium hydroxide against E. faecalis in primary root canal treatment and might be considered as an alternative dressing material between treatment sessions.

Antibacterial efficacy, calcium ion release, and pH using calcium hydroxide with three vehicles

Context

Vehicles combined with calcium hydroxide, as an intracanal medicament, play a key factor in affecting antibacterial, calcium release, and pH.

Aims

The aim of this study is to investigate the effect of three vehicles (glycerin, chlorhexidine gluconate/CHX, and chitosan nanoparticle) combined with calcium hydroxide as an intracanal medicament on antibacterial efficacy against Enterococcus faecalis, calcium ion release, and pH of at different interval times of 7 and 14 days.

Settings and Design

The research was experimental laboratory.

Materials and Methods

Each study used 24 samples of eight teeth each and was randomly divided into three groups based on the vehicle of calcium hydroxide: group 1: glycerin, group 2: CHX, and group 3: chitosan nanoparticles. Each vehicle group was then further divided into two subgroups of four teeth based on the interval times (group A: 7 days and group B: 14 days). The antibacterial efficacy was determined using an agar diffusion method. Calcium ion release was analyzed with atomic absorption spectrometry, and pH was measured using a pH meter.

Statistical Analysis Used

Data from each study were analyzed by two-way ANOVA, followed by Tukey's test with a significance level of 95%.

Results

The results exhibited that chitosan nanoparticles had the highest antibacterial efficacy against E. faecalis, calcium ion release, and pH, while the lowest was glycerin at 7 and 14 days (P < 0.05).

Conclusion

Calcium hydroxide combined with chitosan nanoparticle as an intracanal medicament produced the highest antibacterial efficacy against E. faecalis, calcium ion release, and pH than glycerin and CHX at intervals of 7 and 14 days.

Assessment of Antimicrobial Efficacy of Nano Chitosan, Chlorhexidine, Chlorhexidine/Nano Chitosan Combination versus Sodium Hypochlorite Irrigation in Patients with Necrotic Mandibular Premolars: A Randomized Clinical Trial

AIM: The study was done to assess the antimicrobial effectiveness of Chitosan Nanoparticles (CNPs), Chlorhexidine (CHX), and their combination (CHX/CNPs) versus that of Sodium hypochlorite (NaOCl) in patients with mandibular necrotic premolars and to evaluate their effects on post-operative pain after single-visit endodontic treatment. MATERIALS AND METHODS: Sixty patients with necrotic mandibular premolars were divided randomly to four groups (n = 15) according to the used irrigating solution. Instrumentation was done using rotary ProTaper files. During instrumentation, irrigation was done using 2.5% NaOCl; afterward, canals were flushed with sterile saline. A final flush with the study irrigants was done as follows: 3% CNPs for Group A, 2% CHX for Group B, CHX/CNPs for Group C, and 5.25% NaOCl for Group D. Samples were collected from root canals before and after canal preparation then cultured to assess the number of colony-forming units/ml. All patients were instructed to record their pre- and post-operative pain levels on a numerical rating scale. RESULTS: CNPs and CHX/CNPs were significantly more effective than either CHX or NaOCl; however, there was no significant difference between them against anaerobic bacteria. All tested irrigants were similarly effective against aerobic bacteria. CNPs and CHX/CNPs were associated with significantly lower post-operative pain levels in the first 24 h after treatment. CONCLUSIONS: CNPs and its combination with CHX are significantly more effective than both CHX and NaOCl against anaerobic bacteria isolated from necrotic mandibular premolars. Post-operative pain intensity was significantly lower with CNPs and CNPs/CHX combination than with either NaOCl or CHX.

Effect of Propolis Nanoparticles against Enterococcus faecalis Biofilm in the Root Canal

To determine the antibacterial effect of propolis nanoparticles (PNs) as an endodontic irrigant against Enterococcus faecalis biofilm inside the endodontic root canal system. Two-hundred-ten extracted human teeth were sectioned to obtain 6 mm of the middle third of the root. The root canal was enlarged to an internal diameter of 0.9 mm. The specimens were inoculated with E. faecalis for 21 days. Following this, specimens were randomly divided into seven groups, with 30 dentinal blocks in each group including: group I-saline; group II-propolis 100 µg/mL; group III-propolis 300 µg/mL; group IV-propolis nanoparticle 100 µg/mL; group V-propolis nanoparticle 300µg/mL; group VI-6% sodium hypochlorite; group VII-2% chlorhexidine. Dentin shavings were collected at 200 and 400 μm depths, and total numbers of CFUs were determined at the end of one, five, and ten minutes. The non-parametric Kruskal-Wallis and Mann-Whitney tests were used to compare the differences in reduction in CFUs between all groups, and probability values of p < 0.05 were set as the reference for statistically significant results. The antibacterial effect of PNs as an endodontic irrigant was also assessed against E. faecalis isolates from patients with failed root canal treatment. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were also performed after exposure to PNs. A Raman spectroscope, equipped with a Leica microscope and lenses with curve-fitting Raman software, was used for analysis. The molecular interactions between bioactive compounds of propolis (Pinocembrin, Kaempferol, and Quercetin) and the proteins Sortase A and β-galactosidase were also understood by computational molecular docking studies. PN300 was significantly more effective in reducing CFUs compared to all other groups (p < 0.05) except 6% NaOCl and 2% CHX (p > 0.05) at all time intervals and both depths. At five minutes, 6% NaOCl and 2% CHX were the most effective in reducing CFUs (p < 0.05). However, no significant difference was found between PN300, 6% NaOCl, and 2% CHX at 10 min (p > 0.05). SEM images also showed the maximum reduction in E. faecalis with PN300, 6% NaOCl, and 2% CHX at five and ten minutes. CLSM images showed the number of dead cells in dentin were highest with PN300 compared to PN100 and saline. There was a reduction in the 484 cm^-1 band and an increase in the 870 cm^-1 band in the PN300 group. The detailed observations of the docking poses of bioactive compounds and their interactions with key residues of the binding site in all the three docking protocols revealed that the interactions were consistent with reasonable docking and IFD docking scores. PN300 was equally as effective as 6% NaOCl and 2% CHX in reducing the E. faecalis biofilms.

Influence of a propolis-based irrigant solution on gap formation and bond strength of posts bonded to root canal dentin using different resin cements

This study evaluated the influence of an aqueous propolis-based solution (PROP) on gap formation and bond strength of posts bonded to root canal dentin using resin cements. Endodontically-treated bovine incisors received different irrigation protocols: 1) 2.5% sodium hypochlorite (NaOCl)/17% EDTA/NaOCl; 2) saline solution (NaCl)/EDTA/0.12% chlorhexidine (CHX); 3) NaOCl/PROP/NaOCl; 4) NaCl/PROP/CHX; 5) NaCl/PROP/NaCl. Posts were then bonded with cements: RelyX ARC; Panavia F2.0; or RelyX U200 (n=10). The specimens were cross-sectioned. Gaps were assessed and performed the push-out bond strength test. Surface roughness of dentin fragments was also evaluated. Statistical analysis was performed (5%). RelyX U200 exhibited greater gap-free interfaces. Bond strength varied as a function of cements and irrigation protocols. PROP irrigation had no negative effect on the bond strength (p>0.05). Roughness increased significantly after NaOCl/EDTA/NaOCl, but remained unaltered after PROP irrigation protocols. Propolis-based irrigation protocols do not interfere in the bonding performance of posts cemented to root canal dentin.

Scanning electron microscopic evaluation of smear layer removal at the apical third of root canals using diode laser, endoActivator, and ultrasonics with chitosan: An in vitro study

Aim

The aim of this study was to compare the effect of diode laser, endoActivator, and passive ultrasonics for smear layer removal at the apical third from root canals with 0.2% chitosan.

Materials and Methods

A total of 40 mandibular premolars were decoronated to establish a working length of 12 mm and shaped with ProTaper rotary files up to size F3. In Group A, canals were irrigated with 1 ml of 0.2% chitosan. In Group B, canals were initially irrigated with 0.8 ml of 0.2% chitosan and the remaining 0.2 ml was activated with diode laser. In Group C, canals were irrigated with 1 ml of 0.2% chitosan which was activated with endoActivator. In Group D, canals were irrigated with 0.2% chitosan and activated with passive ultrasonics. All samples were finally flushed with 3 ml of distilled water. The percentage of smear layer removal was analyzed with a scanning electron microscope examination at ×1000 and ×3000. Data were analyzed using Statistical Package for the Social Sciences version 16.0 (SPSS Inc., Chicago, IL, USA) at a significance level of P < 0.05.

Results

The mean value for Group B when compared to Group C for the removal of smear layer was higher, but there was no statistically significant difference between the two groups (P < 0.068 and P < 0.295). Both Group B and Group C showed a statistically significant difference (P < 0.001) when compared to Group A and Group D for the removal of smear layer.

Conclusion

Diode laser and endoActivator with 0.2% chitosan proved better in the removal of the smear layer when compared to passive ultrasonic irrigation.

Antibacterial Effects of Chitosan, Formocresol and CMCP as Pulpectomy Medicament on Enterococcus‎faecalis, Staphylococcus aureus and Streptococcus‎mutans

INTRODUCTION

During pulpectomy of primary teeth, cytotoxic medicaments such as formocresol or camphor mono-chlorophenol (CMCP) are used as medicaments. For the first time it is theorized that chitosan can substitute these traditional materials used in pulpectomy of infectious primary teeth.

METHODS AND MATERIALS

This preliminary in vitro study consisted of two separate phases (n=75), each of which assessed the antibacterial effects of chitosan versus formocresol and CMCP and positive/negative controls (n=15) on three bacteria types [Enterococcus‎faecalis, Staphylococcus aureus, Streptococcus‎mutans, (n=5 per subgroup)]. Phases 1 and 2 concerned respectively with 1- and 7-day effects of these materials. Bacteria were cultured and injected into sterilized canals and colonies were counted. Medicaments were applied and colonies were re-counted after 1 day of treatment (phase 1). Specimens were re-sterilized and re-randomized, and used for phase 2, in which the same procedures were performed for a 7-day period. Effects of agents on bacteria were analyzed statistically (Kruskal-Wallis α=0.05 and Mann-Whitney α=0.017).

RESULTS

Treatments reduced bacterial count either after 1 or 7 days (P=0.000). Their effects on different bacteria types were not significant either after 1 or 7 days (P>0.48). Antibacterial efficacies of treatments (indicated by colony reduction) were significantly different, after 7 days (P=0.045). Antibacterial efficacy of chitosan was similar to that of formocresol or CMCP, in both phases [either after 1 or 7 days of treatment (P>0.017). Formocresol and CMCP had similar efficacies in either phase (P>0.017).

CONCLUSIONS

This preliminary study confirmed the appropriate antibacterial efficacy of chitosan as a medicament in pulpectomy of infectious primary teeth.