Antibiofilm Activity and Cytocompatibility of Novel Enzymatic Root Canal Irrigants.

The aim of this study was to compare the effect of root canal irrigation with superoxidized water and sodium hypochlorite on elimination of Enterococcus faecalis biofilm from the root canal walls. In this experimental study, a total of 32 extracted human central incisors were used. The crowns of all teeth were cut to length of 16 mm. After cleaning and shaping, then the specimens were sterilized in autoclave and then divided into four groups (n=8) as following: group 1 (positive control, root canal irrigation with normal saline), group 2 (negative control without biofilm), group 3 (root canal irrigation with sodium hypochlorite) and group 4 (root canal irrigation with superoxidized water). The bacterial suspension was inserted to root canals of teeth except for negative control group in order to form a microbial biofilm in incubator for 2 weeks. Then all the samples received root canal irrigation for 5 min based on their allocation. At the end, colony forming unit (CFU) was evaluated and biofilm formation and thickness was detected with scanning electron microscopy. The Kruskal Wallis and Dunn's tests were done for biofilm thickness and CFU, respectively with the level of significance set at 0.05. In negative control group no biofilm formation and CFU was present. The CFU counts and biofilm thickness were significantly different between the experimental groups (P=0.001) and both parameters were less in samples with hypochlorite irrigation compared to positive control (52.56±5.82 µm for biofilm thickness and 1.2×107 CFU) and samples irrigated with superoxidized water (2.92±1.76 µm for biofilm thickness and 5.4×104 CFU). Based on this in vitro study reduction in biofilm thickness and CFU/mL was 100% for sodium hypochlorite and for superoxidized water was 98% and 90% for reduction in biofilm thickness and CFU/mL, respectively.

BackgroundBacterial biofilms formed on the root canal wall are often difficult to remove. This study aimed to evaluate the cytotoxic effect and antibacterial efficacy of chitosan when used as root canal irrigant against E. Faecalis and Candida albicans biofilm formed on tooth substrate.Material and MethodsThe present study evaluated antibacterial effect of 0.25% Chitosan, 0.5% Chitosan, 2% chlorhexidine and 3% sodium hypochlorite against Enterococcus faecalis and Candida Albicans. Agar-well diffusion methods, minimal inhibitory concentration tests and biofilm susceptibility assays were used to determine antibacterial activity. Teeth specimens were sectioned to obtain a standardized tooth length of 12mm. Specimens were inoculated with 10 mL of the freshly prepared E. Faecalis suspension and Candida albicans for 4 weeks. The specimens were then instrumented with ProTaper rotary files F3 size. After irrigation with test solution, three sterile paper points were placed into one canal, left for 60 s and transferred to a test tube containing 1 mL of reduced transport fluid. The number of CFU in 1 mL was determined.Results3-week biofilm qualitative assay showed complete inhibition of bacterial growth with 3% Sodium hypochlorite, 2% Chlorhexidine and Chitosan except saline, which showed presence of bacterial growth. Significant reduction of colony forming units (CFU)/mL was observed for the chitosan groups and the antibacterial activity of the chitosan groups was at par with 3% NaOCl and 2% Chlorhexidine. It was observed that the chitosan showed no cytotoxicity at 3mg/ml and 10% cytotoxicity at 6mg/ml.ConclusionsThe use of chitosan as a root canal irrigant might be an alternative considering the various undesirable properties of NaOCl and chlorhexidine. Key words:Biofilm, Candida albicans, Chitosan, Cytotoxicity, Enterococcus faecalis.

Combined Effect of a Mixture of Silver Nanoparticles and Calcium Hydroxide against Enterococcus faecalis Biofilm

Biological and chemical properties of 2-in-1 calcium-chelating and antibacterial root canal irrigants

Frankincense resin exhibits antibacterial potential against various microorganisms, but little is available on its effectiveness against dental root canal biofilm. This study aimed to assess its efficacy as a root canal irrigant against Enterococcus faecalis biofilm. A standard E. faecalis strain underwent antibacterial sensitivity testing with frankincense derived from Boswellia sacra Flück and Boswellia frereana Birdw trees. Frankincense, demonstrating inhibition of bacterial growth, was further evaluated as an irrigant. Root canals of 50 single-canalled human teeth were prepared, then contaminated with E. faecalis and placed into three groups: Group A was irrigated with saline (negative control), Group B was irrigated with 5.25% sodium hypochlorite (NaClO), and Group C was irrigated with frankincense. Microbial sampling pre- and post-irrigation was conducted under aseptic conditions. Colony count reduction percentages were calculated, and the data was analyzed using one-way analyses of variance followed by Tukey's post-hoc test (significance level set at 5%). The antibacterial susceptibility test revealed that only Boswellia sacra Flück frankincense was effective against E. faecalis. Both NaClO and frankincense significantly reduced colony counts compared to saline (p < 0.0001), with no difference between frankincense and NaClO irrigation. Therefore, root canal irrigation with B. sacra frankincense proved as effective against E. faecalis biofilm as NaClO. Further exploration of its potential as a root canal irrigant is recommended.

Biological and chemical properties of new multi-functional root canal irrigants.

To observe the antimicrobial effect of strong acid electrolytic water (SAEW) against an Enterococcus faecalis (E. faecalis) biofilm when used as a root canal irrigant. The effect of SAEW, sodium hypochlorite (5.25%; NaOCl) and sodium chloride (0.9%; normal saline) on E. faecalis biofilm vitality on coverslips was observed by confocal laser scanning microscopy (CLSM). Thirty-five root canals from extracted human teeth were sterilized prior to contamination with E. faecalis for four weeks. Bacterial samples were collected with sterile paper points and plated onto BHI agar plates for 48 h. Root canal walls were observed by scanning electron microscopy before and after instrumentation, together with root canal irrigation with SAEW, NaOCl or normal saline, with or without ultrasonic vibration. Antimicrobial effectiveness was established by counting colony-forming units and analysed by two-way anova. Confocal laser scanning microscopy revealed that SAEW decreased E. faecalis biofilm vitality, and the proportion of dead bacteria increased in accordance with increasing treatment time. Most bacteria in the biofilms were killed after 10-min treatment. No significant difference was observed between SAEW and NaOCl groups at the same treatment time (P > 0.05) or in the susceptibility of E. faecalis to SAEW and NaOCl (P > 0.05) in extracted human teeth with or without ultrasonic activation. SAEW and NaOCl were more effective against E. faecalis biofilm than normal saline, and antimicrobial efficacy was significantly enhanced by ultrasonic vibration (P < 0.05). Strong acid electrolytic water effectively killed E. faecalis in a biofilm both on coverslips and in the root canals of extracted human teeth.

Objective: To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate-based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro. Methods: Cells of Ef were inoculated into the dentinal tubules of single-rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain-heart infusion (BHI) to form 3-week-old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate-based root canal sealer (iRoot SP) (calcium silicate-based group), Gutta-percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate-based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD-t test. Results: After treatment with 5% sodium hypochlorite, in calcium silicate-based group for 4 and 12 weeks more Ef biofilm cells [(75.3±3.5)% and (74.8±3.8)%] were killed than in Gutta-percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate-based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta-percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate-based group for 4 and 12 weeks than in calcium silicate-based group for 1 week (P<0.05). Conclusions: The combined use of sodium hypochlorite and calcium silicate-based root canal sealer kills more biofilm cells in infected dentinal tubules.

Antibacterial Efficacy of Octenisept, Alexidine, Chlorhexidine, and Sodium Hypochlorite against Enterococcus faecalis Biofilms

Although the sodium hypochlorite (NaOCl) solution has been part of the endodontic arsenal for more than one century, current investigations have been unable to determine which NaOCl volume and concentration or which time of application are able to dissolve organic matter without weakening the dental structure during the phase of biomechanical preparation of the root canal. Thus, the objective of the present study was to conduct a systematic literature review with no restriction of publication year or language in order to resolve these questions. The search strategy included the following databases: PubMed, LILACS, Web of Science and ClinicalTrials.gov, and only in vivo human clinical trials were included in the final review. After the removal of duplicates, the systematic literature review yielded 3,717 articles. Of these, 3,685 were excluded after applying the exclusion criteria (ex vivo studies, animal studies, cell-culture studies, narrative review, and studies with no available full texts). A total of 32 full-text articles were assessed for eligibility. After evaluating the full text, all articles were excluded for different reasons. No studies fulfilled our inclusion criteria. This review was unable to answer what time of irrigation, concentration or volume of NaOCl solution can be of maximum effectiveness in endodontic treatment without producing significant changes in the mechanical properties of dentin. Thus, future human clinical studies are needed in order to resolve these questions.Descriptors: Endodontics; Sodium Hypochlorite; Review.ReferênciasSiqueira JF Jr, Guimarães-Pinto T, Rôças IN. Effects of chemomechanical preparation with 2.5% sodium hypochlorite and intracanal medication with calcium hydroxide on cultivable bacteria in infected root canals. 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Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: a randomized clinical trial. Indian J Dent Res.2010;21(4):523-27.Haapasalo M, Shen Y, Qian W, Gao Y. Irrigation in endodontics. Dent Clin North Am. 2010;54(2):291-312.Huffaker SK, Safavi K, Spangberg LS, Kaufman B. Influence of a passive sonic irrigation system on the elimination of bacteria from root canal systems: a clinical study. J Endod. 2010;36(8):1315-18.Kandaswamy D, Venkateshbabu N. Root canal irrigants. J cons dent.2010;13(4),256-64.Kaya S, Yiğit-Özer S, Adigüzel O. Evaluation of radicular dentin erosion and smear layer removal capacity of self-adjusting file using different concentrations of sodium hypochlorite as an initial irrigant. Oral Surg Oral Med Oral Pathol Oral Radiol and Endod.2011;112(4):524-30.Paudel KR, Jaiswal A, Parajuli U, Bajracharya M. Different pharmacological solutions in intracanal irrigation. 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This study evaluated the antimicrobial effectiveness of 6.5% Vitis vinifera grape seed extract (GSE) against Enterococcus faecalis biofilm using confocal laser scanning microscopy (CLSM). Saline solution (SS), 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) were used for comparison. Dentin discs were inoculated with E.faecalis strain establishing a 3-week-old biofilm. Discs (n=10) were exposed to 5.25% NaOCl, 2% CHX, 6.5% GSE and SS (negative control) for 10min. Discs were stained with the fluorescent LIVE/DEAD-BacLight™ dye and analysed using CLSM. The proportion of dead cells in biofilm was analysed using one-way anova and Tukey tests (P<0.05). A higher proportion of dead cells was found in GSE group compared with CHX and SS (P<0.05). NaOCl group was associated with the highest proportion of dead cells (P<0.05). GSE presented antimicrobial activity against E.faecalis; however, NaOCl was the most effective irrigant solution. GSE was more effective than CHX and SS.

To evaluate the antimicrobial action of an irrigant containing silver nanoparticles in an aqueous vehicle (AgNp), sodium hypochlorite and chlorhexidine against Enterococcus faecalis biofilm and infected dentinal tubules. Bovine dentine blocks were used for E.faecalis biofilm development for 21days and irrigated with 94ppm AgNp solution, 2.5% NaOCl and 2% chlorhexidine for 5, 15 and 30min. For infection of dentinal tubules with E.faecalis, dentine specimens from bovine incisors were submitted to a contamination protocol over 5days, with eight centrifugation cycles on every alternate day, and irrigated with the same solutions and time intervals used for the biofilm. The specimens were stained with the Live/Dead technique and evaluated using a confocal laser scanning microscope (CLSM). The bioImage_L software was used for measurement of the total biovolume of biofilm in μm3 and percentage of viable bacteria (green cells) in biofilm and in dentinal tubules found after the irrigation. Statistical analyses were performed using Kruskal-Wallis and Dunn's tests for quantification of viable cells in biofilm, the Friedman test for comparisons of viable bacteria in dentinal tubules in different areas of the root canal and the Mann-Whitney U-test to compare the action of the irrigants between the two methods (P<0.05). The AgNp solution eliminated fewer bacteria, but was able to dissolve more biofilm compared with chlorhexidine (P<0.05). NaOCl had the greatest antimicrobial activity and biofilm dissolution capacity. AgNp solution had less antimicrobial action in infected dentinal tubules compared with NaOCl (P<0.05). The AgNp solution after 5min was more effective in eliminating planktonic bacteria in dentinal tubules than in biofilm, but at 30min fewer viable bacteria were observed in the biofilm compared with intratubular dentine (P<0.05). AgNp irrigant was not as effective against E.faecalis compared to solutions commonly used in root canal treatment. NaOCl is appropriate as an irrigant because it was effective in disrupting biofilm and in eliminating bacteria in biofilms and in dentinal tubules.

Background: One of the main purposes of root canal treatment is the complete debridement of root canals. Regardless of the instrumentation technique used 35% or more of the root canal surfaces have been observed to remain uninstrumented. To remove debris and address these uninstrumented surfaces, it is necessary to copiously irrigate the root canal. Many adjuncts have also been developed and being used in an effort to improve the delivery and effectiveness of these irrigants. Although much research have been conducted on different root canal treatment regime and irrigants used in dentistry, only a little data can be found on the widespread practice or acceptance of such methods. Aims and Objectives: The purpose of this survey was therefore to ascertain the current trends in the use of root canal irrigants and irrigation protocol followed by Endodontists and Postgraduate students across Central India (Madhya Pradesh). Material and Methods: A questionnaire-based survey was conducted and participants were asked to fill in responses to some questions regarding their preferences for root canal irrigation like irrigant selection, irrigant concentration, technique used for delivery and activation of irrigants, etc. Results: The majority of the respondents considered both irrigations as well as instrumentation to be of equal importance. Also, the majority of respondents prefer full-strength sodium hypochlorite (5.25%) while only a few have been found to use its lower concentration (3%). Conclusion: It is essential for future prospects to get an awareness of the properties and actions of irrigants and incorporate them into practice for executing a successful endodontic treatment.

Sodium hypochlorite, is the irrigant of choice for many clinicians, but its strong toxic and damaging effects on vital periapical tissues is always a matter of concern. So, the search for a root canal irrigant with a broad antimicrobial spectrum yet with a limited toxicity on vital tissues is always desirable. The study evaluated antimicrobial efficacy of Electro-Chemically Activated (ECA) water as a root canal irrigant against E. faecalis. Forty eight single rooted human teeth were decoronated to a length of 15mm. All teeth were divided into four test groups (group A - ECA anolyte, group B - 1% sodium hypochlorite, group C - 3% sodium hypochlorite, group D - distilled water) of 12 each. Only 1ml of Ringer's solution and calibrated suspensio of E. faecalis was injected into each canal, aspirated and placed on agar plates and incubated aerobically at 37°C for two days. The suspension was aspirated and spread onto the blood agar plate and incubated. All samples were irrigated with four test solutions and Brain Heart Infusion (BHI) solution was injected into each canal then aspirated and spread onto blood agar and incubated. After inoculations Colony Forming Unit (CFU) and optical density was measured under a microscope and spectrophotometer. The data obtained were statistically analysed by one way ANOVA and Dunkan's multiple range test. CFU reduction was not statistically significant between the test groups. The optical density showed statistically significant difference between the test groups (p≤0.001). The antimicrobial efficacy of ECA was found to be comparable to sodium hypochlorite solutions.

Introduction: The aim of this study was to evaluate the effect of ultrasonic and sonic activation using three irrigants on mature Enterococcus faecalis biofilm. Materials and Methods: Seventy single-rooted premolars were prepared and sterilized. Mature E. faecalis biofilm was developed. Roots were randomly divided into three groups (n = 21) according to activation technique: ultrasonic, sonic, and positive control. Each group was further subdivided into three subgroups (n = 7) according to the irrigant used: 4% propolis, 2% chlorhexidine (CHX), and 2.5% sodium hypochlorite. Samples were cut and scanned using confocal laser scanning microscopy. The fluorescent images were analyzed using Zen imaging software. Data analysis was performed using one way analysis of variance and Tukey's honestly significant difference test for pairwise comparison. Statistical significance was set at 5%. Results: Both activated groups showed a statistically significant bacterial reduction (P ≤ 0.001). CHX showed the highest antibacterial effect. Conclusions: Irrigant activation is an essential step in reduction of bacterial counts. CHX has a potent antibacterial effect against mature E. faecalis biofilm.