A promising approach utilising photothermal energy to disinfect the root canal system: An in vitro investigation.

This study aimed to assess root canal disinfection through various irrigation protocols, including a novel photothermal system called 'LEAP'. Mandibular premolars were infected with Enterococcus faecalis and divided into five groups for different treatments: Group 1: standard needle irrigation; Group 2: passive ultrasonic irrigation; Group 3: GentleWave; Group 4: LEAP; and Group 5: Group 1 + Group 4. Microbial counts were measured before (S1) and after disinfection (S2) using colony-forming units (CFU) and confocal laser scanning microscopy (CLSM). Results revealed a significant reduction in bacterial counts for all groups (p < 0.05). While the percentage of dead bacteria near the canal wall (0-50 µm) did not differ significantly, at 50-150 µm, LEAP and SNI + LEAP exhibited significantly higher bacterial reduction than other groups (p < 0.05). The findings indicate that LEAP is comparable to existing irrigation devices in the main root canal and notably superior in tubular disinfection.

The Hidden World Within: Microbial Dynamics in Root Canal Systems.

Several hundred different microbial taxa have made the oral cavity their home because of their evolution in multiple species communities within the special ecosystem. On the other hand, the dental pulp or internal tissue of the tooth is a connective tissue that is physiologically sterile and where any microbial infiltration is a harmful indication. It causes the pulp tissue to become inflamed, which leads to the death of the pulp and diffuses infection with inflammation to the peri-radicular tissues. Comprehending the biology of biofilms, the microbial makeup, and the host's reaction to infections in the pathobiology of root canal infections has received a lot of attention throughout the last few decades. Such comprehensive knowledge is required to design preventive medicines as well as clinically effective treatment regimens. Surprisingly, clinical approaches have concentrated more on radiographically perfecting channel preparation than on debridement of these intricate root canal systems, despite the clear realization that root canal infections are biofilm mediated. Since the present comprehension of the microbial etiopathogenesis of apical periodontitis highlights the significance of focusing on procedures such as "canal cleaning" and chemo-mechanical disinfection, the exclusive purpose of endodontic therapy is mainly missed while discussing "canal shaping." We thoroughly examine the state of our knowledge of the composition and functional traits of the root canal microbiome in this review. We also go into the difficulties with root canal disinfection and the cutting-edge approaches that try to solve these difficulties. In conclusion, we present essential guidance for prospective research areas, underscoring their significance as crucial considerations in the field of frontiers in oral health.

Recent Advances in Functional Hydrogels for Treating Dental Hard Tissue and Endodontic Diseases.

Oral health is the basis of human health, and almost everyone has been affected by oral diseases. Among them, endodontic disease is one of the most common oral diseases. Limited by the characteristics of oral biomaterials, clinical methods for endodontic disease treatment still face large challenges in terms of reliability and stability. The hydrogel is a kind of good biomaterial with an adjustable 3D network structure, excellent mechanical properties, and biocompatibility and is widely used in the basic and clinical research of endodontic disease. This Review discusses the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment. The emphasis is on the working principles and therapeutic effects of treating different diseases with functional hydrogels. Finally, the challenges and opportunities of hydrogels in oral clinical applications are discussed and proposed. Some viewpoints about the possible development direction of functional hydrogels for oral health in the future are also put forward. Through systematic analysis and conclusion of the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment, this Review may provide significant guidance and inspiration for oral disease and health in the future.

Root Canal Disinfection in Permanent Molars with Apical Lesion by Antimicrobial Photodynamic Therapy: Protocol for a Blind Randomized Clinical Trial.

Objective: The proposed study aims to compare the effectiveness of conventional endodontic treatment (ET) with that of ET associated with antimicrobial photodynamic therapy (aPDT) in patients with apical lesion. Methods: Controlled, double-blind, randomized clinical trial (RCT); superiority study with three parallel arms. Randomization will be conducted in exchange blocks of six, with allocation 1:1:1. The control group will receive conventional ET, while experimental group 1 (EG1) will receive conventional ET + aPDT with laser at 660 nm, fluence of 600 J/cm2; EG2 will receive conventional ET + aPDT with laser at 660 nm, fluence of 1200 J/cm2. The primary outcome will be canal disinfection before treatment, measured by analysis of colony formation (CFU/mL) and the success rate measured after 6 months on the clinical and radiographic evaluations. The mean and standard deviation will be calculated for continuous outcomes, and the CFU/mL mean between groups will be evaluated by ANOVA test. The Chi-squared test will be calculated for binary outcomes. A logistic regression analysis will be performed to assess differences in the success rate between groups, adjusted for the covariates. The Stata 18 software will be used, with a significance threshold of 5%. Conclusions: Few RCTs have evaluated the effectiveness of aPDT in root canal disinfection in patients with permanent dentition presenting apical lesion. New RCTs with larger numbers of participants are needed to support using aPDT as an adjuvant to conventional ET in root canal disinfection for routine use in clinical practice. The trial was registered prospectively in ClinicalTrials.gov (NCT05916859).

Investigation of the Potential of Nanoparticles as a New Drug Delivery System for Endodontic Treatment: An In Vitro Study.

Background: Endodontic treatment involves the removal of infected dental pulp and subsequent disinfection of the root canal system. The effectiveness of drug delivery systems in root canal disinfection is critical for successful treatment outcomes. This in vitro study explores the potential of nanoparticles as a novel drug delivery system for endodontic treatment. Materials and Methods: Nanoparticles were synthesized using a biocompatible polymer and loaded with an antimicrobial agent. A total of 60 extracted human teeth were prepared to create standardized root canal infections. The teeth were randomly divided into three experimental groups: (1) conventional irrigation, (2) nanoparticle irrigation, and (3) control (no irrigation). The root canals in each group were irrigated with their respective solutions for 5 minutes. After treatment, microbial samples were collected from the root canals and cultured for colony-forming unit (CFU) analysis. The depth of penetration of nanoparticles into dentinal tubules was assessed using scanning electron microscopy (SEM). Results: The conventional irrigation group showed a reduction in microbial load from an average of 7.8 × 10^5 CFU/mL (SD ± 1.2 × 10^5) to 3.4 × 10^4 CFU/mL (SD ± 7.9 × 10^3) (P < 0.001). In contrast, the nanoparticle irrigation group exhibited a more significant reduction, with a decrease in CFU to 1.2 × 10^3 CFU/mL (SD ± 4.2 × 10^2) (P < 0.001). SEM analysis revealed deep penetration of nanoparticles into dentinal tubules, reaching an average depth of 150 µm. Conclusion: Nanoparticles loaded with antimicrobial agents demonstrated superior efficacy in reducing microbial load within root canals compared to conventional irrigation. Their ability to penetrate dentinal tubules suggests their potential as an innovative drug delivery system for endodontic treatment. Further research and clinical trials are warranted to validate these promising in vitro results and assess the safety and efficacy of nanoparticles in clinical practice.

40-Year Outcome of Old-School, Non-Surgical Endodontic Treatment: Practice-Based Retrospective Evaluation.

(1) Background: Non-surgical endodontic treatment has been shown to be clinically successful; however, clinical long-term data are scarce. This practice-based retrospective clinical investigation evaluated endodontic outcomes over 40 years and identified relevant clinical co-factors. (2) Methods: Two experienced dental practitioners in two different private dental practices treated 174 patients with 245 teeth from 1969 to 1993. After root canal obturation, either a new direct restoration (amalgam, resin composite, or glass-ionomer cement) or the re-cementation of a pre-existing prosthetic restoration or renewal of prosthetic restoration followed. Metal posts (operator A) or metal screws (operator B) were inserted when coronal substance loss was significant. The primary outcome (i.e., tooth survival) was achieved when the endodontically treated tooth was, in situ, painless and had full function at the end of the observation period. A secondary outcome, the impact of different prognostic factors on survival rate, was evaluated. (3) Results: The overall mean survival was 56.1% of all treated teeth after 40 years of clinical service, resulting in an annual failure rate of 1.1%. Most investigated clinical co-factors (jaw, tooth position, intracanal dressings, post/screw placement, and gender) showed no significant influence on survival. (4) Conclusions: Even with materials and techniques from the 1970s and 1980s, successful root canal treatment was achievable. Except for post-endodontic restorations, most of the evaluated factors had no significant influence on the clinical long-term survival of root canal-treated teeth.

Principle and antimicrobial efficacy of laser-activated irrigation: A narrative review.

In the last two decades, the activation of root canal irrigants with pulsed lasers as an adjunct in root canal treatment has become increasingly popular. This narrative review explains the physical basics and the working mechanism of laser-activated irrigation (LAI), explores the parameters influencing LAI efficacy, considers historical evolutions in the field and summarizes laboratory and clinical evidence with emphasis on the antimicrobial action of LAI. Cavitation is the driving force behind LAI, with growing and imploding vapour bubbles around the laser tip causing various secondary phenomena in the irrigant, leading to intense liquid dynamics throughout the underlying root canal. High-speed imaging research has shown that laser wavelength, pulse energy, pulse length and fibre tip geometry are parameters that influence this cavitation process. Nevertheless, this has not resulted in standardized settings for LAI. Consequently, there is significant variability in studies assessing LAI efficacy, complicating the synthesis of results. Laboratory studies in extracted teeth suggest that, with regard to canal disinfection, LAI is superior to conventional irrigation and there is a trend of higher antimicrobial efficacy of LAI compared to ultrasonic activation. Clinical evidence is limited to trials demonstrating similar postoperative pain levels after LAI versus no activation or ultrasonic activation. Clinical evidence concerning the effect of LAI on healing of apical periodontitis as yet is scarce.

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

Objective: 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. Material and Methods: 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. Results: 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. Conclusion: 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.

CLSM-Guided Imaging for Quantifying Endodontic Disinfection.

Elimination of microbes in the root canal system is crucial for achieving long-term success in endodontic treatment. Further efforts in study design and standardization are needed in order to improve the validity and comparability of in vitro results on endodontic disinfection procedures, in turn improving clinical outcomes. This study optimizes two models at all steps: tooth selection, pretreatment, inoculation method (by growth or centrifugation), and confocal laser scanning microscopy (CLSM)-guided imaging of LIVE/DEAD-stained specimens. Individual anatomical conditions lead to substantial differences in penetration depth. Sclerosis grading (SCG), a classification system introduced in this study, provides information about the sclerosis status of the dentine and is helpful for careful, specific, and comparable tooth selection in in vitro studies. Sonically activated EDTA for the pretreatment of roots, inoculation of Enterococcus faecalis in an overflow model, 3-4 weeks of incubation, as well as polishing of dentine slices before staining, led to advances in the visualization of bacterial penetration and irrigation depths. In contrast, NaOCl pretreatment negatively affected performance reproducibility and should be avoided in any pretreatment. Nonsclerotized teeth (SCG0) can be used for microbial semilunar-shaped inoculation by centrifugation as a "quick-and-dirty" model for initial orientation. In conclusion, CLSM-guided imaging for quantifying endodontic infection/disinfection is a very powerful method after the fine-tuning of materials and methods.

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.

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. OBJECTIVE: To 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. DESIGN: Clinical 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. RESULTS: E. faecalis turned out to be the main microorganism in mature biofilm, this was related to the presence of ß-galactosidase detected by vibrational Raman spectroscopy. After the enzymatic treatment of the extracellular polymeric substance, the presence of mannose and glucose was established. CONCLUSIONS: The 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.

Bioburden assessment of necrotic teeth disinfected with sodium hypochlorite, diode laser, and photodynamic therapy using flow cytometry-a randomized double-blinded clinical trial.

This study aimed to comparatively evaluate the disinfecting potential of sodium hypochlorite, diode laser, and photodynamic therapy in non-vital teeth with or without periapical rarefaction. Forty-five patients with the diagnosis of pulp necrosis with apical rarefaction were randomly assigned to three groups (n = 15) based on the disinfection protocol. Access cavities were prepared and pre-instrumentation microbial samples were taken using a paper point. Working length determination followed by cleaning and shaping with rotary files was performed. The canals were lubricated with ethylenediaminetetraacetic acid (EDTA) during instrumentation and finally rinsed with copious amounts of saline. Canals in group 1 were irrigated with 5 mL of 5.25% NaOCl, those in group 2 received irradiation with 808-nm diode laser (30 s, 7W), and those in group 3 were soaked with methylene blue photosensitizer (5 min) before irradiation with 660-nm diode laser (3 min). Post-disinfection microbial samples were collected using a paper point. Pre- and post-disinfection live bacterial counts were analyzed using a flow cytometer. The data were statistically analyzed using one-way ANOVA and Student's t-test. Comparison of pre-instrumentation mean live bacterial count showed no significant difference between the groups (p > 0.05). The mean live bacterial count post-disinfection was 41.07%, 46.99%, and 34.45% in groups 1-3 respectively. A significant reduction in the bacterial count was seen following disinfection in all the groups (p < 0.05). It can be concluded that both diode laser and photodynamic therapy were equally effective as 5.25% NaOCl in reducing the bioburden in root canals. TRIAL REGISTRATION: CTRI/2018/03/012667.

Comparative Evaluation of the Efficacy of Chlorhexidine, Diode Laser, and Saline in Reducing the Microbial Count in Primary Teeth Root Canals: An In Vivo Study.

Context: Different irrigation materials in pediatric endodontics. Aims: To evaluate the efficacy of chlorhexidine (CHX), diode laser, and saline in primary teeth root canals. Settings and design: This manuscript is designed to know the effectiveness of the different root canal irrigants and laser irradiation technology in primary teeth root canals. Materials and methods: A total of 60 primary teeth from 60 children were selected and divided into three groups of 20 each. Group I (CHX), group II (diode laser), and group III (saline). Pulp tissue was extirpated from the root canals of primary teeth, and samples were collected using sterile paper points. After cleaning and shaping, the root canals of the teeth in each group were disinfected using CHX and saline or irradiated with a diode laser. The samples were collected again and sent for microbiological examination. Statistical analysis used: Statistical analyzes were performed using the Wilcoxon signed-rank test, Mann-Whitney U test, and Kruskal-Wallis one-way analysis of variance. All analyzes were conducted using the Statistical Package for the Social Sciences version 23.0. Results: The colony-forming unit (CFU) of the predisinfection sample served as a baseline for comparisons throughout the study. The mean microbial counts of all the postdisinfected samples were reduced after disinfection. Intergroup comparisons showed significant results between groups I and III (CHX and saline) and groups II and III (diode laser and saline) (p < 0.01), whereas groups I and II (CHX and diode laser) showed nonsignificant results (p < 0.092). Conclusion: Diode laser irradiation succeeded in reducing root canal infection when compared with 2% CHX. Diode laser irradiation can also be used for disinfecting the root canal in primary teeth. How to cite this article: Botu RK, Rachuri P, Martha S, et al. Comparative Evaluation of the Efficacy of Chlorhexidine, Diode Laser, and Saline in Reducing the Microbial Count in Primary Teeth Root Canals: An In Vivo Study. Int J Clin Pediatr Dent 2023;16(3):459-463.

Effects of an Nd:YAP laser used for root canal disinfection in pulp regenerative therapy: a pilot study.

This study aimed to compare the disinfection effects between a triple antibiotic paste and neodymium-doped yttrium aluminum perovskite (Nd:YAP) laser in pulp regenerative therapy and evaluate corresponding therapeutic effects based on apical radiographs and cone-beam computed tomography (CBCT). Sixty-six immature permanent teeth in 66 patients diagnosed with acute or chronic apical periodontitis were analyzed. All teeth were given pulp regenerative therapy. The patients were categorized into a control (triple antibiotic paste) and an experimental (Nd:YAP laser) group. Teeth in the experimental group were disinfected using an Nd:YAP laser, while those in the control group were disinfected using a triple antibiotic paste. Clinical and radiological examinations were performed every 3-6 months after treatment and followed up for 24 months. Statistical analysis was performed after clinical examination and showed that after one week of treatment, symptoms persisted in two teeth in the control group and two teeth in the experimental group. Two weeks later, the clinical symptoms disappeared in all teeth (p > 0.05). After 24 months of follow-up, the clinical symptoms recurred in two teeth in the control group and one tooth in the experimental group. On radiographic examination, 31 and 27 teeth showed continued root development, and three and two teeth showed no obvious root development in the control and experimental groups, respectively. The pulp sensibility test was positive in four teeth in both groups, with no significant difference between the two groups (p > 0.05). The results of this study suggest that endodontic irradiation with an Nd:YAP laser could be an effective alternative to triple antibiotic paste during disinfection of pulp regenerative therapy. Treatment outcomes were assessed using apical radiographs and CBCT, and no negative prognostic effects of the Nd:YAP laser on pulp regenerative therapy were found.

Effect of antimicrobial photodynamic therapy on the reduction of bacteria and virulence factors in teeth with primary endodontic infection.

OBJECTIVE: To evaluate the effectiveness of supplemental photodynamic therapy for improving the bacterial removal and the levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) by conducting a clinical trial. METHODOLOGY: Twenty-four root canals with pulp necrosis and periapical lesion were selected and randomly divided into conventional group using endodontic treatment with chemo-mechanical preparation (CMP) alone (n = 12) and a group using antimicrobial photodynamic therapy (aPDT) after CMP (n = 12). The samples were collected before and after CMP (conventional group) and after photodynamic therapy (aPDT group). A photosensitizer (0.005% methylene blue) was applied to the root canal for 3 minutes after CMP, whereas aPDT was performed by using a red laser with a power of 30Mw and energy density of 9J/cm2 for 90 s per root canal. Culture technique was performed to determine the bacterial colony forming units. LPS and LTA levels were quantified by using limulus amoebocyte lysate (LAL) assay and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: All samples showed growth of viable bacteria on Fastidious Anaerobe Agar (FAA), with an average of 5.19 × 105 CFU/ mL. CMP was effective in decreasing viable bacteria (p < 0.05), whereas there was a significant decrease (p < 0.05) in the samples treated with aPDT compared to those submitted to CMP. LPS and LTA were detected in all initial samples, with mean values of 20.561 EU/mL and 430.91 pg/mL, respectively. Both CMP and aPDT groups significantly decreased the levels of LPS and LTA (p < 0.05), with a statistical difference between the groups regarding aPDT (p < 0.05). CONCLUSION: Photodynamic therapy as an adjunct to CMP proved to be effective in improving root canal disinfection and reducing the LPS and LTA levels in teeth with primary endodontic infection.

Comparative Evaluation of Bacterial Reduction by Laser-Activated Irrigation Technique (LAI) With Conventional Needle Irrigation (CNI) in Single-Rooted Teeth With Pulpal Necrosis: A Single-Blinded Randomized Controlled Trial.

Aim  To compare the bacterial reduction in single-rooted teeth with pulpal necrosis after laser-activated irrigation technique (LAI) and conventional needle irrigation (CNI). Methodology In this clinical trial (CTRI/2021/09/047767), 32 patients with pulpal necrosis were enrolled. Under complete aseptic conditions, access cavity preparation was done and the baseline sample S1 was collected from the root canal using paper points. After chemo-mechanical preparation they were allocated into two groups, following block randomization; Group A - CNI with 27 gauge side-vented needle, Group B - LAI with pulsed Er,Cr:YSGG (erbium, chromium:yttrium-scandium-gallium-garnet) (2780 nm) laser. After irrigant activation, canals were dried and a second sample S2 was taken using paper points. Microbial analysis using quantitative polymerase chain reaction (qPCR) was done to quantify the bacterial reduction among the two groups. Inter-group and intra-group analysis was done using the independent student t-test and Bonferroni test, respectively. The data was represented in terms of quantification cycle (Cq) values, which are inversely proportional to the microbial count.  Results There was no significant difference in S1 between the two groups (mean difference=0.0205; p=0.912). There was a significant difference in S2 between the two groups for the organisms (mean difference=0.8042; p=0.000). The mean percentage of bacterial reduction in CNI was 10.82% and in LAI it was 25.92%.  There was a significant difference in S1 through S2 within the two groups for the organisms (p=0.000). The mean difference of Cq value is high for LAI compared to CNI (1.3494).  The fold change was calculated by taking the ΔCq value and ΔΔCq value after the logarithmic transformation of the Cq value. LAI showed lower levels of DNA at S2 similar to CNI. There is no significant difference in mean fold change between CNI and LAI (p=0.564).  Conclusion This clinical trial concluded that both LAI and CNI were effective in bacterial reduction. There was greater bacterial reduction with LAI (25.92%) than with the CNI (10.82%) in single-rooted teeth with pulpal necrosis using qPCR analysis.

Comparative Evaluation of the Antibacterial Efficacy of Chlorhexidine and 810 nm Diode Laser in the Disinfection of Root Canals Contaminated With Enterococcus faecalis: An In Vitro Study.

INTRODUCTION: This study compared the antibacterial efficacy of three different root canal irrigants, sodium hypochlorite, chlorhexidine and 810 nm diode laser and diode laser in combination with chlorhexidine in root canals contaminated with Enterococcus faecalis. Methods: Fifty extracted mandibular first premolars were decoronated at the cementoenamel junction and cut at the apical end; biomechanical preparation was done, autoclaved and contaminated with Enterococcus faecalis. The specimens were divided into five groups containing 10 teeth each: group I: saline (negative control), group II: 2.5% sodium hypochlorite, group III: 2% chlorhexidine gluconate solution, group IV: diode laser, and group V: diode laser in combination with 2% chlorhexidine. Disinfection was carried out, after which dentinal shavings were collected from the specimens of each group. Antimicrobial efficacy was tested by counting the colony-forming units of viable Enterococcus faecalis on the agar plates. One-way ANOVA and Scheffe's post hoc test were done to analyse the results. RESULTS: Diode laser with chlorhexidine group showed minimum colony-forming units followed by the diode laser group. The post hoc test showed a statistically significant difference between saline, 2.5% sodium hypochlorite and 2% chlorhexidine groups (P = 0.001) and a non-significant difference between diode laser and diode laser with chlorhexidine group (P = 0.997). CONCLUSIONS: Diode laser can be used as a root canal disinfectant alone or in combination with chlorhexidine.

Antibacterial and anti-inflammatory efficacy of N-acetyl cysteine in endodontic treatment: a scoping review.

BACKGROUND: This scoping review systematically summarized the available evidence about the efficacy of N-acetyl cysteine (NAC) as an intracanal antibacterial and/or anti-inflammatory. METHODS: PubMed, Scopus, Web of Science, and Google scholar search engines/databases were searched up to February 2022 to retrieve relevant studies. The studies were evaluated for eligibility criteria, and identifying relevant studies. RESULTS: Out of 193 studies, 15 fulfilled the inclusion criteria and were processed for data extraction. Thirteen in vitro studies assessed antibacterial/antibiofilm efficacy of NAC, and reported good and promising efficacy: NAC was found as efficacious as the comparators (chlorhexidine, sodium hypochlorite, calcium hydroxide), or even showed higher efficacy. Regarding the anti-inflammatory efficacy of NAC, one in vitro study found it equivalent to, while one clinical trial revealed it more efficacious than calcium hydroxide. CONCLUSIONS: There is accumulating evidence on the anti-microbial and anti-inflammatory efficacy of NAC in context of endodontics. However, further clinical trials with robust methodology and objective and reliable clinical, biological and microbial outcomes are warranted to translate its use for clinical practice on humans.

Influence of irrigation and laser assisted root canal disinfection protocols on dislocation resistance of a bioceramic sealer.

BACKGROUND: It is not yet clear how different irrigation protocols and intracanal laser irradiation effects bioceramic sealers. In this vitro study, we aimed to evaluate the dislocation resistance of a bioceramic root canal sealer after different laser-assisted disinfection protocols and irrigants. METHODS: Sixty extracted human straight single-canal teeth were instrumented, and randomly divided into five experimental groups (n=10) according to the disinfection protocol used: group 1, conventional needle irrigation (CI) with sodium hypochlorite (NaOCl)+ethylenediaminotetraacetic acid (EDTA)+NaOCl; group 2, Photon initiated photoacoustic streaming (PIPS) of NaOCl+EDTA+NaOCl; group 3, NaOCl+EDTA+diode laser; group 4, NaOCl+EDTA+photodynamic therapy (PDT); group 5, CI with NaOCl+EDTA+Chlorhexidine (CHX); and control group without any treatment. The root canals were filled with a bioceramic root canal sealer (BioRoot RCS) using the single-cone filling technique. After three weeks of storage, the samples from each canal thirds were transversely sectioned and the push-out test was performed. RESULTS: The PIPS group showed the lowest dislocation resistance values in the coronal third (p>0.05), and no difference was observed among the other groups (p<0.05). The dislocation resistance in the middle and apical thirds was the highest in the diode laser group (p<0.05). CONCLUSION: Final root canal irradiation with diode laser led to improved dislocation resistance of the bioceramic sealer. PDT did not adversely affect the dislocation resistance of BioRoot RCS. The PIPS reduced the dislocation resistance values in the coronal third, but not in the middle and apical thirds.

The effect of different intracanal medicaments on the dislodgement resistance of mineral trioxide aggregate.

BACKGROUND: This study aimed to assess the effect of different commercially used calcium hydroxide [Ca(OH)2], the mixture of Ca(OH)2 + silver nanoparticles (AgNPs), and other intracanal medicaments on dislodgement resistance of mineral trioxide aggregate (MTA) to root canal dentin in short- and long-term application. METHODS: Forty-six human single-rooted maxillary teeth were sectioned horizontally at mid-root into 1 mm thick slices. The lumen of the slices was standardized using #2-#5 Gates Glidden drills to a standard diameter of 1.3 mm in all samples. After smear layer removal, the samples were randomly divided into eight groups (n = 20) and treated with the following medicaments; Ca(OH)2 paste, Calcipex, Metapex, chlorhexidine (CHX), Ca(OH)2/CHX paste, Ca(OH)2/AgNPs, triple antibiotic paste and control group (normal saline). The samples were then incubated at 37 °C with 100% humidity for 1 week. Next, half of the teeth in each group (n = 10) were removed from the incubator and washed in an ultrasonic bath. ProRoot MTA was placed in the canal lumen and the samples were incubated at 37 °C and 100% humidity for 48 h to allow complete setting of MTA. The remaining half in each group (n = 10) was subjected to the same process after 1 month of application of medicaments. The dislodgement resistance of MTA to root dentin was measured. The data were analysed using two-way ANOVA and Tukey's post hoc test. RESULTS: No significant difference was noted in dislodgement resistance of samples after 1 week and 1 month in any group (P > 0.05). The only significant difference was noted between the control and CHX groups and the higher dislodgement resistance was recorded in the CHX group (P = 0.006). No other significant differences were noted between the groups (P > 0.05). CONCLUSION: Duration of application and the type of intracanal medicament do not affect the dislodgement resistance of MTA to root dentin. Although there was no statistically significant difference in the dislodgment resistance of MTA between the medicaments, CHX had a promising effect.