Root Canal Disinfection Research Articles

Antimicrobial Efficacy of Different Concentrations of Sodium Hypochlorite in the Elimination of Enterococcus Faecalis: An In-vitro Study

Introduction: Primary teeth are equally important as permanent teeth. Endodontic therapy aids in the preservation and maintenance of extremely carious primary teeth. For root canal therapy to be successful, root canals must be properly prepared and effectively irrigated. Sodium Hypochlorite (NaOCl) has been the gold standard for root canal treatment of primary teeth. However, there are a few drawbacks to using higher concentrations of sodium hypochlorite, such as toxic reactions from its apical penetration. In addition, an excess of irrigation fluid via the apical region could harm the permanent tooth underneath. Therefore, it is crucial to select the proper concentration to preserve the delicate balance between effectiveness and safety. Aim: The present in-vitro study was conducted in the city of Chennai, Tamil Nadu, between March and June 2022. The study aimed to evaluate the effectiveness of lower concentrations of sodium hypochlorite, such as 1%, 0.5%, and 0.25%, against Enterococcus faecalis. Materials and Methods: The antibacterial activity of different concentrations of sodium hypochlorite (1%, 0.5%, and 0.25%) against Enterococcus faecalis was performed using Muller Hinton agar. Three Mueller Hinton agar plates were prepared and sterilised for 15 minutes for each concentration. The volumes used were 25 μL, 50 μL, and 100 μL, respectively. E. faecalis was swabbed and poured into the sterilised plates. The plates were incubated for 24 hours at 37°C. After incubation, the plates were examined, and their zone of Inhibition was determined. ANOVA test was applied with Post-hoc Tukey’s analysis. Results: One-way ANOVA test showed that there was a significant difference with a p-value <0.001 in all three groups. Post-hoc Tukey’s analysis was done, and the test showed that the highest zone of inhibition was seen with 1% sodium hypochlorite at 100 μL, with zone diameter of 39 mm, and the least zone of inhibition was seen with 0.25% sodium hypochlorite solution at 25 μL, with zone diamter of 22 mm. Conclusion: The results of the present study show that a 1% sodium hypochlorite solution can be used to successfully disinfect root canals, indicating its potential as an effective antimicrobial agent in endodontic procedures.

Surgical Management of Extruded Fractured Instrument Beyond the Periapical Area: A Case Report with Two-year Follow-up

A fractured instrument is an undesirable endodontic mishap that can prevent complete root canal disinfection, thereby affecting the root canal treatment outcome. The present case discussed the surgical management of an extruded fractured barbed broach at the apical third of maxillary right first premolar. A 28-year-old female presented with an endodontic failure on tooth 14 and was diagnosed as previously root canal treated with symptomatic apical periodontitis. Radiographic examination revealed a straightline radiopacity structure that was 2 mm in length extruded from the apical root-end, suggesting a fractured instrument. The case was successfully managed through endodontic microsurgery. The present case emphasises the significance of cone-beam computed tomography as a valuable tool for diagnosis and investigation, while also offering supplementary information for the planning of surgical treatment.

Polymeric nanoparticles delivery circumvents bacterial resistance to ciprofloxacin

Polymeric nanoparticles delivery circumvents bacterial resistance to ciprofloxacin

Iontophoresis use for increasing drug penetration into root canals and dentinal tubules: A proof-of-concept study

IntroductionThe success of endodontic treatment depends on the significant disinfection of the root canal system, its irregularities, and dentinal tubules. However, achieving complete disinfection remains challenging, with frequent failures and occurrence of secondary infections. Here, we propose using iontophoresis to increase the penetration and distribution of disinfecting agents into root canals, using methylene blue for proof-of-concept. MethodsThe marker was applied in bovine root canals, and the radial distribution of the dye in the dentinal tubules was evaluated by optical microscopy. Iontophoresis was applied at 0.5 and 1.5 mA for 5 and 15 min. ResultsA significant statistical difference (p < 0.05) was observed in the marker penetration between passive and iontophoretic applications. Both current density and application time had an important effect on methylene blue distribution, with a greater efficacy delivery to the apical region achieved after 1.5 mA for 5 min or 0.5 mA for 15 min, showing longer application time can compensate for lower application current. ConclusionIontophoresis increases the penetration and distribution of methylene blue into bovine root canals and dentinal tubules, including its innermost portions. Clinical significanceIontophoresis has shown to be a promising technique for root canal and dentinal tubule disinfection.

Remineralization of Dentin with Cerium Oxide and Its Potential Use for Root Canal Disinfection.

This study was to investigate a novel antibacterial biomimetic mineralization strategy for exploring its potential application for root canal disinfection when stabilized cerium oxide was used. A biomimetic mineralization solution (BMS) consisting of cerium nitrate and dextran was prepared. Single-layer collagen fibrils, collagen membranes, demineralized dentin, and root canal system were treated with the BMS for mineralization. The mineralized samples underwent comprehensive characterization using various techniques, including transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (STEM), selected-area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and micro-CT. Additionally, the antimicrobial properties of the BMS and the remineralized dentin were also analyzed with broth microdilution method, live/dead staining, and SEM. Cerium ions in the BMS underwent a transformation into cerium oxide nanoparticles, which were deposited in the inter- and intra-fibrillar collagen spaces through a meticulous bottom-up process. XPS analysis disclosed the presence of both Ce (III) and Ce (IV) of the generated cerium oxides. A comprehensive examination utilizing SEM and micro-CT identified the presence of cerium oxide nanoparticles deposited within the dentinal tubules and lateral canals of the root canal system. The BMS and remineralized dentin exhibited substantial antibacterial efficacy against E. faecalis, as substantiated by assessments involving the broth dilution method and live/dead staining technique. The SEM findings revealed the cell morphological changes of deceased E. faecalis. This study successfully demonstrated antibacterial biomimetic mineralization as well as sealing dentinal tubules and lateral branches of root canals using cerium nitrate and dextran. This novel biomimetic mineralization could be used as an alternative strategy for root canal disinfection.

Does aPDT reduce bacterial load in endodontic infected teeth? A systematic review and meta-analysis.

This systematic review investigated whether antimicrobial photodynamic therapy (aPDT) after chemomechanical root canal disinfection (CD) yields a greater microbial load reduction than only CD. An electronic literature search was conducted on four databases up to November 2022, with no language or publication date restrictions. Randomized and non-randomized clinical trials were included if participants had a primary endodontic infection in permanent teeth, and if microbial loads before and after using aPDT were compared. Two researchers independently screened titles and abstracts to determine study eligibility. Assessments included risk of bias and methodological quality. This review was registered in PROSPERO (CRD42020181783). Eight studies were included in the qualitative analysis, and six were eligible for meta-analysis. In the random effects model, aPDT significantly improved the results of root canal disinfection when compared with standard protocols for cleaning and shaping (p = 0.04, 95% CI -1.72, -0.05). Subgroup analysis suggested that aPDT has a better effect on reducing the load of anaerobic microorganisms (p = 0.003, 95% CI -3.36, -0.69). The use of aPDT as an adjunct to chemomechanical disinfection promotes additional reduction of the microbial load and, therefore, seems to improve the results of root canal treatments in permanent teeth with a primary endodontic infection. However, certainty of evidence should be improved.

Innovative Curved-Tip Reactor for Non-Thermal Plasma and Plasma-Treated Water Generation: Synergistic Impact Comparison with Sodium Hypochlorite in Dental Root Canal Disinfection.

Non-thermal plasmas (NTPs), known as cold atmospheric plasmas (CAPs), hold great potential for diverse medical applications, including dentistry. However, traditional linear and rigid dielectric barrier discharge reactors used for NTP generation encounter limitations in accessing oral cavities and root canals. To address this issue, we have developed an innovative NTP reactor featuring an angled end for improved accessibility. The central copper electrode, with a 0.59 mm diameter and adjustable length for desired angulation, is coated with zircon powder (ZrSiO4) to ensure stable NTP generation. This central electrode is housed within a stainless steel tube (3 mm internal diameter, 8 mm external diameter, and 100 mm length) with a 27° angle at one end, making it ergonomically suitable for oral applications. NTP generation involves polarizing the reactor electrodes with 13.56 MHz radio frequency signals, using helium gas as a working medium. We introduce plasma-treated water (PTW) as an adjunctive therapy to enhance biofilm eradication within root canals. A synergistic approach combining NTP and PTW is employed and compared to the gold standard (sodium hypochlorite, NaOCl), effectively neutralizing Enterococcus faecalis bacteria, even in scenarios involving biofilms. Moreover, applying NTP in both gaseous and liquid environments successfully achieves bacterial inactivation at varying treatment durations, demonstrating the device's suitability for medical use in treating root canal biofilms. The proposed NTP reactor, characterized by its innovative design, offers a practical and specific approach to plasma treatment in dental applications. It holds promise in combatting bacterial infections in root canals and oral cavities.

Impact of contracted endodontic access cavity designs on root canal disinfection using diode laser: An “In-Vitro” Study

Introduction: New approaches for minimal invasive endodontic access cavity designs had been introduced for preserving the structural integrity of the offending tooth. Diode laser has been now widely used in root canal disinfection and showing highly promising results. Aim: to evaluate the impact of contracted endodontic access cavity designs on root canal disinfection using diode laser. Materials and Methods: Fifty-four intact freshly extracted human mandibular first molars were selected for the use in this study. Only the mesial roots of the selected samples were included in this study. Samples were randomly divided into three equal groups (n=18) according to the type of access cavity performed. Group (1): conventional access cavities, Group (2): Ninja access cavities, and Group (3): truss access cavities. Isolates of Enterococcus Faecalis (E.Fecacalis) were introduced in the root canals of the mesial roots of the selected samples. Samples were further sub-divided into two equal sub-groups (n=9) according to the disinfection method. Sub-group (a): Diode laser disinfection, and Sub-group (b): NaOCl 2.5% followed by EDTA 17% irrigation. Bacterial evaluation was performed using confocal laser scanning electron microscope. Results: The results showed that using Diode laser disinfection have shown higher bacterial reduction in comparison to NaOCl irrigation, but with no statistically significant difference. For access cavity designs, regardless of the type of disinfection used, conventional access cavities have shown the highest bacterial reduction, with the least bacterial reduction with Ninja access cavities. Conclusion: Contracted endodontic access cavities did not offer any advantages in comparison with the conventional endodontic access cavities regarding bacterial reduction. Diode laser can be used as an effective adjunct tool in root canal disinfection.

Pulp Regenerative Therapy Using Autologous Dental Pulp Stem Cells in a Mature Tooth with Apical Periodontitis: A Case Report

The utility and feasibility of pulp regenerative therapy with autologous dental pulp stem cells (DPSCs) in mature teeth with irreversible pulpitis were clinically demonstrated. On the other hand, there is no evidence of the utility of DPSCs in mature teeth with apical periodontitis. The aim of this case report was to describe the potential utility of regenerative cell therapy in mature teeth with apical periodontitis. A 44-year-old man was referred for pulp regeneration due to a periapical lesion in his maxillary first premolar. Root canal disinfection was performed by irrigation and intracanal medication by nanobubbles with levofloxacin and amphotericin B in addition to conventional irrigation. Autologous DPSCs isolated from an extracted third molar were transplanted into the root canal after residual bacteria and fungi were below the detection level by polymerase chain reaction assay using universal genes to amplify specific regions within bacterial 16S ribosomal DNA and fungal ribosomal DNA (ITS1), respectively. There were no adverse events or systemic toxicity assessed for clinical evaluations during the 79-week-follow-up period and laboratory evaluations after 4 weeks. The affected tooth was responsive to the electric pulp test. Cone-beam computed tomographic imaging revealed a reduced lesion size, remission of the periapical tissue, and mineralized tissue formation in the apical part of the canal after 79 weeks. The signal intensity on magnetic resonance imaging of the regenerated tissue in the affected tooth was comparable to that of the normal pulp in the adjacent teeth after 24 weeks. This case report demonstrated the potential use of DPSCs for pulp regenerative therapy in mature teeth with apical periodontitis.

A IMPORTÂNCIA DA IRRIGAÇÃO ULTRASSÔNICA PASSIVA PARA O SUCESSO DO TRATAMENTO ENDODÔNTICO: revisão narrativa de literatura

The objective of this study was to highlight the advantages of Passive Ultrasonic Irrigation (PUI) in endodontic treatments, describing its techniques, execution, and effective outcomes. The research was based on a narrative literature review, with a search in national and international databases, using specific keywords. The results demonstrate that the selection of an appropriate irrigating solution is fundamental since the failure of endodontic treatment is often related to the survival of microorganisms in the root canals. The ideal irrigation should be chosen based on the specific needs of each case, considering the chemical properties of the irrigating solutions. PUI is an effective technique for activating irrigating solutions in root canals and may be more efficient in cleaning the canals than simultaneous ultrasonic instrumentation. PUI is particularly useful in curved canals, and a smooth wire can be as effective as a cutting K-file. The study also highlights the continuous evolution of dentistry and the need to invest in advanced technologies to enhance clinical outcomes. It is concluded that PUI is a promising technique that offers significant benefits for the success of endodontic treatments. Its ability to reach challenging areas and its effectiveness in disinfecting root canals emphasize the relevance of the technique in dental practice. It is expected that this knowledge will contribute to improving irrigation protocols and, consequently, the effectiveness of endodontic treatments.

Multispecies oral biofilm and identification of components as treatment target

Endodontic infections involve a multispecies biofilm, making it difficult to choose an antimicrobial treatment. Characteristics such as the pathogens involved and number of microorganisms, nutrients, material surface to develop the biofilm, flow and oxygenation conditions are important for biofilm development using in vitro models. ObjectiveTo develop a standardized biofilm model, which replicates the main features (chemical, microbiological, and topographical) of an infected root canal tooth to detect components as treatment target. DesignClinical strains of Enterococcus faecalis, Candida albicans, and Actinomyces israelii were isolated, and a multispecies biofilm was developed using continuous laminar flow reactors under anaerobic conditions in human dental roots. The microbiological composition was determined by counting colony-forming units and scanning electron microscope micrographs. In addition, the chemical composition of the exopolymeric matrix was determined by vibrational Raman spectroscopy and liquid chromatography of biofilm supernatant treated with enzyme. ResultsE. faecalis turned out to be the main microorganism in mature biofilm, this was related to the presence of β-galactosidase detected by vibrational Raman spectroscopy. After the enzymatic treatment of the extracellular polymeric substance, the presence of mannose and glucose was established. ConclusionsThe present work contributes to better understanding of standard conditions to develop a multispecies biofilm in human dental roots, which could have an impact on the generation of new root canal disinfection techniques in endodontic pathologies.

Treatment strategy of lateral canals during root canal therapy

Lateral canals are small branches from the main root canal, usually extending from the dentin and cementum into the periodontal ligament, mostly located at the lower 1/3 of the apical portion. Due to the complex and varied anatomical morphology as well as the high incidence, it becomes an important factor affecting the effect of root canal therapy and a difficult point in this process. It is of great clinical significance to master the treatment strategy of lateral canals during root canal therapy. This article reviews the anatomical characteristics of lateral canals, as well as the clinical identification, treatment strategy and the laboratory detection methods of lateral canals in the process of root canal preparation, disinfection, and obturation.

Level of evidence of scientific research presented at a national endodontic conference

ABSTRACT Introduction: Evidence-based endodontics improves patient care by combining clinical competence, research, and patient values. This review critically assessed scientific studies at an Indian national endodontic conference. Materials and Methods: Scientific research papers presented at the 30th National Endodontic Conference of the Indian Endodontic Society 2022 were categorized according to the area of interest and the level of evidence. Cuzick’s test for trend was utilized to compare the level of evidence of the abstracts at the National Endodontic Conference (n = 396) and those published from the 20th European Society of Endodontology Biennial Congress 2022 (n = 91). Results: Endodontics (n = 265, 64.6%) was the most examined domain, followed by diagnosis (n = 49, 12.4%), restorative dentistry (n = 46, 11.6%), and miscellaneous (n = 45; 11.6%). Root canal disinfection (n = 64, 16.1%) was the most prevalent subcategory, followed by endodontic instruments and apparatus (n = 40, 10.1%) and restorations (n = 36, 9%). Laboratory and animal (nonhuman) studies dominated the national conference abstracts (n = 219, 55.3%), followed by level VI (n = 108; 27.2%), level III (n = 40; 10.1%), and level II (n = 23, 5.9%). There was no significant difference between the national and international conference levels of evidence (P = 0.318). Discussion: National and international conferences lack laboratory-to-clinical translation. Researchers must do high-quality, relevant, nonredundant evidence-based research. Conclusion: New studies should use evidence-based research to efficiently address valid research questions and provide predictable and high-quality patient treatment.

Analyze the clinical effect of YAG laser combined with sodium hypochlorite in root canal treatment of pulpitis.

To compare and analyze the clinical therapeutic effects of sodium hypochlorite combined with Nd: YAG laser and sodium hypochlorite alone for root canal disinfection in patients with pulpitis. Patients with pulpitis were divided into control group and observation group according to random number table method. Both groups received root canal treatment, while the control group received root canal irrigation with 1% sodium hypochlorite. The observation group was irrigated with 1% sodium hypochlorite combined with Nd: YAG laser. Periodontal index, inflammatory index, life quality score and bacterial infection clearance rate of the two groups were compared before and 3 months after treatment. The total effective rate of the observation group was 95.35%, which was higher than that of the control group 79.07% (p < .05). After 3 months of treatment, the periodontal index and inflammation level of both groups decreased, and the observation group was lower than that in the control group (p < .05). The life quality score and infection clearance rate of observation group were significantly higher than control group (p < .05). Compared with root canal irrigation with 1% sodium hypochlorite alone, sodium hypochlorite combined with Nd: YAG laser for root canal disinfection can significantly improve the therapeutic effect, relieve inflammatory reaction, and decrease bacterial infection.

Effectiveness of different supplementary protocols for remaining filling material removal in endodontic reintervention: an integrative review.

The aim of this study was to perform an integrative review to identify the most effective supplementary protocols used after filling material (FM) removal and root canal reinstrumentation, during endodontic reintervention. The literature search was performed on the electronic databases PubMed and Latin American and Caribbean Health Sciences Literature (LILACS), using a combination of specific scientific descriptors. Selection criteria accepted articles published in English, Spanish and Portuguese languages, up to August 2021, involving in vitro and ex vivo studies. After applying the eligibility criteria, 46 articles were included for qualitative analysis. The tool for qualitative analysis of quasi-experimental studies of the Joanna Briggs Institute was used to determine the risk of bias of the included articles. The selected articles provided important data regarding the following supplementary protocols: sonic and ultrasonic activation of the irrigating solution; the use of ultrasonic inserts, XP-endo system instruments, and photon-induced photoacoustic streaming for mechanical debridement; and new devices as GentleWave system, and the self-adjusting file. Overall, all supplementary protocols demonstrated efficacy in removing the remaining FM. The implementation of various supplementary protocols can effectively remove the remaining FM from the root canal walls, although complete removal is not always achieved. However, it was not possible to determine the most effective protocol. Conversely, their association can enhance remaining FM removal. Remaining FM attached to root canal walls hinders proper chemical-mechanical preparation during endodontic reintervention. Supplementary protocols optimize the remaining FM removal, enhancing cleaning and disinfection of root canal.

Direct and residual antimicrobial effect of 2% chlorhexidine gel, double antibiotic paste and chitosan- chlorhexidine nanoparticles as intracanal medicaments against Enterococcus faecalis and Candida albicans in primary molars: an in-vitro study

BackgroundThorough disinfection of root canals in primary molars may be complicated by the complex root canal morphology. This in-vitro study aimed to compare direct and residual antimicrobial effect of 2% chlorhexidine (CHX) gel, 500 mg/ml double antibiotic paste (DAP) and chitosan-chlorhexidine nanoparticles (CS-CHX NPs) as intracanal medicaments against Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans) in primary molars.MethodsMesial roots of 63 mandibular second primary molars were infected with E. faecalis and C. albicans. Teeth were divided into 9 groups: Ia: (CS-CHX NPs), IIa: (CHX), IIIa: (DAP), IVa: chitosan nanoparticles (CSNPs) in which medicaments were placed for 3 days, groups Ib: (CS-CHX NPs), IIb: CHX, IIIb: (DAP), IVb: (CSNPs) in which medicaments were placed for 7 days, and Group V (control): teeth were infected, irrigated with saline, and sampled 3- and 7-days post-infection. Microbiological samples were obtained after infection, 3, and 7 days after medicament placement and 7 days after medicament removal for both time points. One-way ANOVA, Tukey’s post hoc test and paired t-test were used at p < 0.05.ResultsCS-CHX NPs had the highest anticandidal effect which was comparable to CHX and significantly higher than other medicaments (p < 0.001) at both time points. CS-CHX NPs had the highest effect against E. faecalis which was comparable to DAP and significantly higher than other medicaments (p < 0.001) at 3 days. All medicaments showed similar effect against E. faecalis after 7 days. The 7-days placement significantly increased the antimicrobial effect against both micro-organisms in all groups, except CS-CHX NPs which showed an insignificant increase. CS-CHX NPs showed the highest residual effect against both micro-organisms that increased with 7-days placement.ConclusionCSNPs and CHX combination showed a synergistic effect against both micro-organisms. CS-CHX NPs displayed a higher effect at a shorter period compared to other medicaments, yet its residual effect was higher with 7-days placement.

Evaluation of Antibacterial Efficacy of High-Intensity Focused Ultrasound Versus Photodynamic Therapy Against Enterococcus faecalis-Infected Root Canals.

The high incidence of endodontic failure is associated with the remnants of Enterococcus faecalis present within the intricate anatomies of the root canal system (RCS), often inaccessible by the current endodontic practices. This study was aimed at evaluating the effect of high-intensity focused ultrasound (HIFU) and photodynamic therapy (PDT) on E. faecalis biofilms in artificially infected root canals for the potential application in current endodontic practices. Forty-five single-rooted extracted teeth were instrumented using hand files, sterilized in an autoclave, infected with E. faecalis and incubated for 4 wk. The specimens were treated and identified as follows: Control, 4% sodium hypochlorite (NaOCl); riboflavin (1 mg/mL); light only; HIFU (250 kHz, 20 W, 60s); PDT; riboflavin/HIFU; light/HIFU; and riboflavin/HIFU/light. Bactericidal efficacy was determined by colony-forming units (CFU), (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Enterococcus faecalis biofilm exhibited significantly lower metabolic activity when treated with HIFU (250 kHz, 20 W, 60 s) compared with the control (4% NaOCl) and PDT groups. A similar phenomenon was observed with the CFU assay. HIFU remained the most effective treatment modality, with consistent results in CLSM and SEM. This study highlighted the potential application of HIFU as an adjunct drug-free, non-destructive root canal disinfection method for endodontic treatment, suggesting an alternative to the current gold standard of 4% NaOCl and PDT.

Evaluation the antibacterial efficacy of sodium hypochlorite in combination with two different photodynamic therapy protocols against Enterococcus Faecalis in Infected root canals: An in-vitro experiment

BackgroundPhotodynamic therapy (PDT) is an antimicrobial approach that can be used as an adjunctive safe technique for root canal disinfection. In this study, we aimed to evaluate the antibacterial efficacy of PDT with indocyanine green and toluidine blue in combination with sodium hypochlorite (NaOCl) in compared with NaOCl alone against Enterococcus faecalis in infected root canals. MethodsSixty five root canals of sound human premolars were collected. First, the teeth were sterilized, then 60 root canals were inoculated with the E. faecalis, and 5 samples served as negative control remained uncontaminated. The contaminated root canals were randomly assigned into 4 experimental groups (n=15): (1) NaOCl, (2) NaOCl+ PDT-1 (toluidine blue + 630nm LED), (3) NaOCl+ PDT-2 (indocyanine green + 808nm diode laser), and (4): positive control (no treatment). Then, the colony-forming units (CFU/mL) of E. faecalis were calculated in all the groups. Moreover, 5 samples from each group were examined under a scanning electron microscope. The data were analyzed by independent T-test and the Mann-Whitney U test at the significance level of 0.05. ResultsThe CFU count was significantly lower in the indocyanine green-PDT group in comparison with other groups (p˂0.05). The mean of CFU in the positive control group was significantly higher than the other groups (p˂0.05). No significant difference was detected between NaOCl and toluidine blue –PDT group (p=1.00). ConclusionIndocyanine green- PDT improved the antibacterial effects of NaOCl against E. faecalis, while toluidine blue – mediated PDT had no significant additional effect on NaOCl.

Is ozonated water a suitable alternative to sodium hypochlorite in root canal disinfection?

Aim: This study evaluated the disinfection ability of ozonated water in comparison to sodium hypochlorite (NaOCl) solution in root canals infected with Enterococcus faecalis. Material and methods: Forty single-rooted bovine teeth were standardized and prepared using K-files. The root canals were contaminated for 21 days and the first microbial sample was collected from root canals (S1). The teeth were divided into 5 groups: Saline solution, 0.5% NaOCl, Ozonated water, and 2 control groups. The root canals were irrigated with 20 mL of the selected solution for an uninterrupted period of 20 minutes, the irrigant solution was maintained resting for 5 minutes and then, samples were collected from root canals (S2). The data was evaluated using Kruskal Wallis and Wilcoxon tests (P&lt;0.05). Results: The NaOCl group had lower microbial counts (P&lt;0.05) and a higher percentage of microbiological reduction than the other groups (P&lt;0.05). Conclusion: It was determined that ozonated water was not a suitable substitute for NaOCl.

Electrochemical Disinfection of Root Canals Bears No Risk of Damaging Periapical Tissues in a Dog Model

Boron-doped diamond (BDD) electrodes have been advocated as a potential treatment alternative to the established methods for root canal disinfection. As healing of periapical tissue is important in this context, the associated risk of host tissue damage was to be evaluated. Following in vitro cell culture experiments (HeLa cells), root canal treatment was performed in an animal trial comparing BDD electrode application and the currently used rinsing media with respect to cell viability and host tissue damage. Statistical analyses comparing the size of radiolucency were based on Kruskal-Wallis and Nemenyi’s All Pairs tests (α = 0.05). The direct application of BDD electrodes had a time-dependent effect on cell viability comparable to H2O2, NaOCl, and CHX application. In contrast to the chemical treatment, the effect of BDD electrodes was transient. Conventionally treated teeth and teeth additionally treated with BDD electrodes did not significantly differ from each other with respect to the size of the periapical radiolucency as observed radiographically (vertical p = 0.998 and horizontal p = 0.878) and histologically (vertical p = 0.940 and horizontal p = 0.862). While showing greater disinfection efficiency, the application of BDD electrodes for the electrochemical disinfection of root canals does not have a greater risk of host tissue damage compared to the conventional treatment.