Spectrophotometric Analysis of Apical Extrusion of Sodium Hypochlorite using Different Irrigation Protocols in an Ex Vivo Model of Immature Teeth.

OBJECTIVE: To evaluate the effect of different agitation methods on apical extrusion of 1.5% sodium hypochlorite (NaOCl) in an ex vivo model of immature teeth. METHODS: Sixty extracted human inferior incisors were prepared to simulate immature teeth and embedded in an artificial root socket made of silicone impression material. The teeth were then divided into four groups: Conventional needle irrigation (CNI) alone, CNI supplemented with Ultrasonic Irrigant Activation (UIA), EasyClean (EC), or XP-endo Finisher (XPF). Extruded NaOCl was collected, reacted with m-cresol purple, and its absorbance values were measured. The data were statistically analyzed using One-way analysis of variance with a significance level of 5%. RESULTS: All groups showed apically extruded irrigating solution, and the mean volumes of extruded NaOCl did not differ significantly between any of the test groups (p⟩0.05). CONCLUSION: The activation of 1.5% NaOCL by UIA, EC, or XPF as supplementary to CNI does not promote greater apical extrusion when compared to CNI alone in simulated immature teeth.

Development of Chlorhexidine Digluconate and Lippia sidoides Essential Oil Loaded in Microemulsion for Disinfection of Dental Root Canals: Substantivity Profile and Antimicrobial Activity.

The dental intracanal disinfection is crucial to achieve the success of endodontic treatment, avoiding the maintenance of endodontic infections. Chlorhexidine digluconate can act as an irrigating agent for it. However, it can cause tissue irritation in high concentrations. Therefore, combinations with other antimicrobial agents and more efficient therapeutic alternatives are studied, which make it possible to administer drugs more safely and with minimal adverse effects. Thus, the objective of this study was the development of a microemulsion containing chlorhexidine digluconate and essential oil of Lippia sidoides to be used for disinfection of dental root canals and to evaluate its profile of substantivity and antimicrobial activity. The microemulsions were obtained through phase diagrams, using the spontaneous formation method. We completed a physical-chemical characterization and evaluate the stability of the microemulsions, in addition to the substantivity profile in a bovine root dentin model, and in vitro antibacterial effect on Enterococcus faecalis. A method for quantifying chlorhexidine was developed using UV-Vis spectroscopy. The microemulsions showed acid pH, conductivity above 1.3 µScm-1, and dispersion index similar to water. The microemulsions showed antimicrobial inhibition halos similar to the commercial gel conventionally used, but with four times more substantivity to dentinal tissues. Microemulsions were obtained as a therapeutic alternative to formulations available on the market, presenting themselves as a system with great potential for the administration of drugs for disinfection of root canals.

Allium sativum extract as an irrigant in pulpectomy of primary molars: A 12-month short-term evaluation.

This study indented to assess the clinical and radiographic assessment of Allium sativum extract as an intracanal irrigant for pulpectomy of primary molars. Ninety children with 110 teeth submitted were categorized into two groups. Clinical and radiographic success rates were checked at 3, 6, and 12 months. Qui-square test at a level of significance was ˂0.05. There was no statistically significant difference (p Ë‚ .05) between the two groups that has not been detected clinically or radiographically. Clinical and radiographic success rates of garlic extract at 3 months were (80% and 72.7%), which declined at 6 and 12 months to be 76.4% 6 and 74.5% respectively. For NaOCl group, clinical and radiographic success rates were 87.3% and 85.5% at 3 months, 87.3% and 87.3% at 6 months and 89.1% and 87.3% at 12 months. A. sativum extract can be used efficiently as an irrigant for pulpectomy of primary molar root canals.

Evaluation of Sodium Hypochlorite Irrigant, Bingpeng Irrigant, and Fufang Bingpeng Irrigant as Endodontic Irrigants During Passive Ultrasonic Irrigation.

Given the increasing prevalence of antibiotic resistance among bacterial strains and the side effects caused by synthetic drugs, it is increasingly important to investigate potential herbal alternatives. In the present study, antimicrobial, cell cytotoxicity, and cleaning tests were performed to evaluate the potential of Fufang Bingpeng irrigant as a root canal irrigant, in addition to q-PCR and high-throughput sequencing analyses. Our in vitro results showed a low minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Fufang Bingpeng irrigant against Porphyromonas gingivalis ATCC 33277 (6.25 and 12.5%, respectively), Prevotella intermedius ATCC 25611 (6.25 and 6.25%, respectively), Fusobacterium nucleatum ATCC 25286 (6.25 and 6.25%, respectively), Enterococcus faecalis ATCC 19433 (25 and 25%, respectively), and Bacteriodes fragilis ATCC 25285 (12.5 and 12.5%, respectively). Furthermore, it effectively removed the remaining debris and increased the number of open dentinal tubules in root canals compared to the NaCl irrigant (p < 0.05). Fufang Bingpeng irrigant also presented low cytotoxicity to L929 cells compared to the NaClO irrigant. The in vivo results indicated that all irrigants used significantly reduced the number of bacteria compared to the number prior to treatment, and only 1/104.95 bacteria remained in the root canal following the use of Fufang Bingpeng irrigant (p < 0.001). Moreover, the high-throughput sequencing results indicated that all irrigants markedly enhanced the α diversity in the root canal compared to the before preparation control group, while Fufang Bingpeng maintained better microbial diversity than other groups. Therefore, Fufang Bingpeng irrigant presents a promising alternative for use as a root canal irrigant in clinical settings.

Postoperative Quality of Life Following Conventional Endodontic Intracanal Irrigation Compared with Laser-Activated Irrigation: A Randomized Clinical Study.

Objective: The aim of this randomized clinical study was to evaluate the effect of laser-activated irrigation using a photon-induced photoacoustic streaming (PIPS) technique on postoperative pain following completion of root canal obturation. Methods: Fifty-six patients were enrolled in this randomized clinical trial. Fifty-six healthy premolars or molars with asymptomatic irreversible pulpitis, symptomatic irreversible pulpitis, or symptomatic pulpal necrosis, with or without apical periodontitis, were mechanically prepared for endodontic treatment and divided into two groups. Patients were randomly allocated to treatment groups. In the positive control group G1, the final irrigation with 2 cc of 5.25% sodium hypochlorite (NaOCl) was achieved using a 27G needle, introduced into the canal to a distance of 5 mm from the predetermined working length. In the experimental group G2, the root canals were irrigated with 17% ethyldiamine tetric acid (EDTA) and 5.25% NaOCl following the PIPS protocol, using an Er:YAG 2940 nm laser (LightWalker ATS®; Fotona, Slovenia) with a 600 µm diameter tip and operating parameters of 20 mJ per pulse, 15 Hz frequency, 0.3 W average power, and a 50-µs pulse duration. Postoperatively, the patients were advised to take a minor analgesic (ibuprofen 400 mg) in the event of pain perception. Postoperative pain levels were assessed after 24, 48, and 72 h and 7 days through the use of a Visual Analogue Scale questionnaire, completed by each patient. Data were analyzed using Kolmogorov-Smirnov, Fisher Exact, Chi square, Mann-Whitney test, and Friedman's test. The level of significance was set at α = 0.05. Results: There was no significant difference between the laser-irradiated group and the control group (p < 0.5). Laser activation of irrigating solutions did not increase postoperative pain. Conclusions: The outcome of this investigation indicated that PIPS was as effective as conventional irrigation in relation to postoperative pain, making this activation technique interesting to use for supplementary root canal disinfection.

Effect of Different Concentrations of Sodium Hypochlorite on Outcome of Primary Root Canal Treatment: A Randomized Controlled Trial.

INTRODUCTION: The aim of this study was to evaluate the effect of 2 different concentrations of sodium hypochlorite on healing and postoperative pain after primary endodontic treatment. METHODS: One hundred mandibular molars with pulp necrosis and chronic apical periodontitis were randomly assigned to 2 treatment groups: high-concentration (HC) 5% sodium hypochlorite and low-concentration (LC) 1% sodium hypochlorite. Root canal treatment was performed using a standardized protocol. Canals were prepared using equal volumes of respective irrigants after each instrument change. After chemomechanical preparation, the final flush was performed with 5 mL 17% EDTA solution followed by 5 mL 5% or 1% sodium hypochlorite depending on the group. All patients were asked to record the degree of pain on a visual analog scale every 24 hours for 1 week. At the second visit, canals were obturated, and the teeth were restored permanently. Clinical and radiographic evaluations were performed every 3 months for 12 months. The data collected were statistically analyzed. RESULTS: Eighty-six teeth were available for evaluation at the 1-year follow-up. The overall healing rate observed was 76.7%. Greater healing was observed in the HC (81.4%) group compared with the LC group (72.1%), but the difference was not statistically significant (P > .05). No significant differences in pain incidence and pain scores were found between the 2 groups (P >.05), with lower values reported in the LC group. CONCLUSIONS: The use of LC or HC sodium hypochlorite did not result in a significant difference in the clinical outcome.

Direct and Indirect Effect of Chlorhexidine on Survival of Stem Cells from the Apical Papilla and Its Neutralization.

INTRODUCTION: Several irrigants have been used for disinfection in regenerative endodontic procedures including chlorhexidine (CHX). In this context, the antibacterial properties of disinfectants are mainly in focus of research even though they may have an undesirable impact on the fate of stem cells. In this study, we hypothesized that CHX has both a direct effect when applied to stem cells of the apical papilla (SCAPs) and an indirect effect when SCAPs are exposed to dentin previously conditioned with CHX. METHODS: Cell toxicity was evaluated in vitro using the CellTox green fluorescence assay (Promega, Madison, WI) and CellTiter-Glo (Promega) after SCAPs were exposed directly to a dynamic concentration range of CHX; apical papilla explant cultures were stained with ApopTag (Merck Millipore, Billerica, MA) after culture with CHX. Furthermore, standardized slabs from human dentin were treated with CHX and consecutively rinsed in EDTA, L-α-lecithin (Sigma-Aldrich, St Louis, MO), or L-α-lecithin followed by EDTA. After that, SCAPs were cultured on the slabs for 5 days, and cellular viability was determined (indirect effect). Data were treated nonparametrically and analyzed using the Krukal-Wallis test (P ≤ .05). RESULTS: Direct exposure of SCAPs to CHX highly affected cell viability at concentrations above 10-3%, whereas lower concentrations had no adverse effect. During the initial 60 minutes, concentrations of 10-2% CHX or higher resulted in early pronounced toxicity with a maximum effect within 15 minutes after exposure. Likewise, CHX-conditioned dentin slabs were detrimental to SCAP survival; however, the deleterious effects were completely reversed by neutralization with L-α-lecithin. CONCLUSIONS: Chlorhexidine is toxic to SCAPs when applied directly or indirectly via conditioned dentin. If applied for a short time and neutralized by L-α-lecithin, it can be a gentle and cell-preserving disinfectant before endodontic regeneration.

Comparison of resorption rate of primary teeth treated with alternative lesion sterilization and tissue repair and conventional endodontic treatment: An in vivo randomized clinical trial.

BACKGROUND: Complete pulpectomy and elimination of wide range of microorganisms from infected primary root canals is not possible through conventional endodontic procedures. Thus, lesion sterilization and tissue repair (LSTR) therapy employing 3Mix tri-antibiotic paste have been used as an alternative endodontic modality for infected primary teeth. AIM: This study aims to evaluate the root resorption rate of endodontically treated mandibular primary molars with conventional endodontic treatment or LSTR therapy and to compare it with their healthy contralateral teeth. MATERIALS AND METHODS: Fifty carious first and second primary mandibular molars from 25 healthy children aged 7-10 years were treated with two different endodontic procedures using LSTR Therapy and conventional endodontic treatment. The resorption rate of these teeth with healthy contralateral teeth was compared clinically and radiographically at 3, 6, 12 and 36 months using Chi-square test. RESULTS: At 12 months, clinically, there was no difference in the outcomes of both groups but radiographically, statistically significant difference (P < 0.001) in root resorption between treated teeth and their controls in both the groups was observed. At 36 months, interradicular bone resorption around the crown of succedaneous teeth and their delayed eruption was noted in LSTR group. CONCLUSIONS: LSTR therapy could be a viable treatment modality for infected/nonvital primary molars with poor prognosis and intended to be maintained for shorter duration in the oral cavity as natural space maintainers.

Determination of residual parachloroaniline produced by endodontic treatment after the use of 5% sodium hypochlorite and 2% chlorhexidine combined: an ex-vivo study

ABSTRACT: Aim: The objective of this work was to determine the concentrations of irrigating solutions and the residual content of parachloroaniline (PCA) formed after endodontic irrigation, using 5% NaOCl, 0.9% NaCl, 10% EDTA and 2% CHX 2%. Methodology Twenty premolars were used and 13 samples were collected per tooth from each of the treatment phases. Samples of: NaOCl, EDTA, CHX and PCA were quantified by UV and visible spectrophotometry. Results: Sodium hypochlorite decreased its concentration from 3.8% to 3.4% in phases 1 to 4. In phases 5, 6 and 7, residual NaOCl was measured with concentrations of 0.007%, 0.003% and 0.001% %. The concentration of EDTA decreased to 8.85% in phase 8. In phases 9, 10 and 11, irrigated with serum, EDTA was quantified with concentrations of 0.013% to 0.002% and NaOCl values of 0.0011% to 0, 0006%. In phases 12 and 13, CHX concentrations were 1.850% and 1.812% and PCA values were 0.0005% and 0.0007%. PCA formation occurred in presence of 2% CHX and residual NaClO and was detected colorimetrically in phases 12 and 13. Conclusions. During endodontic irrigation the concentration of 5% NaOCl decreases significantly in the first four phases and the concentrations of EDTA and CHX also decrease. There is PCA training in the last stages of the procedure.

Evaluation of Apically Extruded Debris using Two Niti Systems Associated with Two Irrigation Techniques in Primary Teeth.

PURPOSE: The aim of this study was to compare the effects of 2 NiTi file systems [Twisted File Adaptive (TFA) and Reciproc (RP)] and 2 irrigation techniques [Conventional needle irrigation (CNI) and Laser activated irrigation (LAI)] on the amount of apically extruded debris in primary maxillary molars. STUDY DESIGN: Sixty extracted primary maxillary molars were randomly divided into 4 groups. The mesio-buccal roots of teeth in 4 groups were instrumented using TFA with LAI, RP with LAI, TFA with CNI and RP with CNI respectively. Debris extruded during instrumentation was collected into Eppendorf tubes and amounts were determined. The data were analyzed using two-way ANOVA test at 0.05 level of significance. RESULTS: The results indicated all instrumentation and irrigation systems caused a measurable apical extrusion of debris. However, no statistically significant difference in debris extrusion was observed between irrigation techniques or instrumentation systems (P > 0.05). The total amount of debris extruded apically by LAI was greater than that by CNI. CONCLUSIONS: All instrumentation and irrigation techniques caused debris extrusion. However, the optimal laser activation time and power settings should be investigated to ensure minimal extrusion of debris and irrigant due to cavitation and pressure during LAI in root canal treatment.

Supplementary Steps for Removing Hard Tissue Debris from Isthmus-containing Canal Systems.

INTRODUCTION: The purpose of this ex vivo study was to evaluate the percentage reduction of accumulated hard tissue debris (AHTD) in the mesial root canal system of mandibular molars under different final irrigation regimens by means of micro-computed tomographic imaging. METHODS: Sixty curved mesial roots of mandibular molars with 2 independent canals joint apically by an isthmus (Vertucci type II) were selected. Specimens were scanned at a resolution of 12.5 µm, anatomically matched, and distributed into 3 groups (n = 20) according to the preparation protocol: Self-Adjusting File (SAF; ReDent Nova, Ra'anana, Israel), Reciproc (VDW GmbH, Munich, Germany), and Revo-S (Micro-Mega, Besançon, France) systems. Then, each group was subdivided into 2 subgroups (n = 10) according to the final irrigation protocol with the SAF or EndoVac system (Discus Dental, Culver City, CA). The percentage volume and percentage reduction of AHTD after root canal preparation and final irrigation protocols were statistically compared using 1-way analysis of variance, the paired sample and the independent Student's t tests. The level of significance was set at 5%. RESULTS: Within groups, the mean percentage volume was significantly reduced after the final irrigation procedures in either the SAF (from 1.52%-1.78% to 1.01%-1.20%) or EndoVac (from 2.11%-2.23% to 1.31%-1.52%) subgroups (P < .05). In the experimental groups, the mean percentage reduction of AHTD ranged from 29.15%-39.90% after the irrigation protocols, with no statistical difference between groups (P > .05). CONCLUSIONS: None of the irrigation approaches succeeded in rendering the mesial root canal system free of AHTD. A similar percentage reduction of AHTD was achieved after final irrigation protocols using either the SAF or EndoVac system.

Accuracy of Turbidimetric Limulus Amebocyte Lysate Assay for the Recovery of Endotoxin Interacted with Commonly Used Antimicrobial Agents of Endodontic Therapy.

INTRODUCTION: This study was conducted to investigate whether the interaction between the turbidimetric limulus amebocyte lysate (LAL) substrate for endotoxin measurement and the substances/antimicrobial agents used in endodontic therapy can lead to the inhibition/enhancement of endotoxin recovery. METHODS: Ten microliters of a suspension of Escherichia coli endotoxin (O55:B55) was inoculated and kept in contact for 1 hour with different substances categorized as follows: group 1: auxiliary chemical substances: 5.25% and 2.5% sodium hypochlorite solutions, 2% chlorhexidine (CHX) (gel and solution), 1% Natrosol gel (Drogal Chemicals and Pharmaceuticals Ltd, Piracicaba, SP, Brazil), 17% EDTA, 10% citric acid, 3% hydrogen peroxide, 5% sodium thiosulfate, and 0.5% Tween 80 associated with 0.07% soy lecithin (Drogal Chemicals and Pharmaceuticals Ltd) and group 2: intracanal medications: neomycin/polymyxin B/hydrocortisone (Otosporin; Glaxo Wellcome, Rio de Janeiro, RJ, Brazil); calcium hydroxide (Ca[OH]2); Ca(OH)2 + 2% CHX gel; Ca(OH)2 + 2% CHX gel + zinc oxide eugenol; Ca(OH)2 + camphorated paramonochlorophenol (Calen; S.S. White, Rio de Janeiro, RJ, Brazil); triple antibiotic paste; mineral trioxide aggregate (MTA); and iodoform. Positive and negative controls consisted of root canal hemorrhagic exudate and pyrogen-free sterile water, respectively. All samples were diluted up to a 10:4 dilution. Each dilution was individually examined by the turbidimetric LAL assay. Collected data were analyzed through performance characteristics of the LAL assay such as linearity, coefficient of variation percentage, and product positive control (PPC) values. RESULTS: Correlation coefficient (≥0.980) and coefficient of variation percentage (<10%) of the standard curve in triplicate showed the tests' linearity. Spike recovery of auxiliary chemical substances achieved PPC values ranging from 50%-197%, showing no interferences with LAL substrate. Conversely, 3% hydrogen peroxide achieved product inhibition in which endotoxin values were underestimated even after the 10:4 dilutions. Regarding intracanal medicaments, neomycin/polymyxin B/hydrocortisone also inhibited endotoxin detection in all dilutions investigated (PPC values <50%). In contrast, Ca(OH)2 + 2% CHX gel + ZOE as well as triple antibiotic paste led to the enhancement of endotoxin detection in which endotoxin values could not be validated by the turbidimetric kinetic LAL assay (PPC value >200%). CONCLUSIONS: The performance characteristics of the kinetic turbidimetric assay for endotoxin measurement, such as precision and reproducibility, are modulated by the interaction of the LAL substrate with the substances/antimicrobial agents used in endodontic therapy.

Influence of irrigation protocols on the bond strength of fiber posts cemented with a self-adhesive luting agent 24 hours after endodontic treatment.

The aim of this in vitro study was to evaluate the influence of different irrigation protocols on the bond strength, at different root depths, of fiber posts cemented with a self-adhesive cement 24 hours after endodontic treatment. Fifty-six bovine incisor roots were endodontically prepared and separated into 7 groups (n = 8) according to irrigation protocols: group 1, sterile saline (control); group 2, chlorhexidine (CHX) gel 2% and saline; group 3, sodium hypochlorite (NaOCl) 5.25% and saline; group 4, CHX and saline (final irrigation with ethylenediaminetetraacetic acid [EDTA] 17%); group 5, NaOCl and saline (final irrigation with EDTA); group 6, CHX and saline (final irrigation with NaOCl and EDTA); and group 7, NaOCl (final irrigation with CHX and EDTA). No statistically significant difference was found among the groups. Within the limitations of this study, it can be concluded that the different irrigation protocols did not influence the bond strength of self-adhesive resin cement, which presented similar behaviors at the 3 root depths studied.

Efficacy of laser-driven irrigation versus ultrasonic in removing an airlock from the apical third of a narrow root canal.

The purpose of the study was to test the hypothesis that air entrapment occurs in the apical third of a root canal during irrigation. A second objective was to test the null hypothesis that there is no difference between laser-driven irrigation (an erbium, chromium:yttrium-scandium-gallium-garnet laser) and passive ultrasonic irrigation in removing an airlock from the apical third. One hundred twenty extracted human teeth with single narrow root canals were randomised into two experimental groups (n = 40) and two control groups (n = 20). The specimens were shaped using hand instruments up to a size 30/0.02 file. The teeth were irrigated with a mixture of saline, radiopaque contrast and ink in solution. In the passive ultrasonic irrigation group, the irrigant was activated with an ultrasonic device for 60 s. In the laser group, the irrigant was activated with a laser for 60 s. It was concluded that if the insertion of irrigation needle is shorter than the working length, air entrapment may develop in the apical third, but the use of laser-driven irrigation is completely effective in removing it.

Assessment of smear layer removal protocols in curved root canals.

This study sought to assess if the final rinse protocol interferes with the smear layer removal in the apical area of curved canals. Sixty-four extracted human mandibular molars with curved mesial roots were instrumented with rotary files and divided into six experimental groups for final rinse: 1EDTA (syringe irrigation with 1 mL of 17% ethylenediaminetetraacetic acid (EDTA) ), 5EDTA (syringe irrigation with 5 mL of 17% EDTA), 1EDTA-P (syringe irrigation with 1 mL of 17% EDTA + pumping with gutta-percha point), 5EDTA-P (syringe irrigation with 5 mL of 17% EDTA + pumping with gutta-percha point), 1EDTA-EA (syringe irrigation with 1 mL of 17% EDTA + EndoActivator) and 5EDTA-EA (syringe irrigation with 5 mL of 17% EDTA + EndoActivator). Final rinsing was carried out over 3 min. The specimens were split lengthwise and observed under a scanning electron microscope using a score criterion. Comparison among the groups showed statistically significant difference only between the 5EDTA-EA group and the other groups (Kruskal-Wallis and Dunn's post-hoc tests, P < 0.05). The combination of 5 mL of 17% EDTA and 3 mL of 2.5% sodium hypochlorite (NaOCl) with the EndoActivator removed smear layer from the apical area of curved root canals more effectively than the other protocols used.

Debris remaining in the apical third of root canals after chemomechanical preparation by using sodium hypochlorite and glyde: an in vivo study.

INTRODUCTION: During chemomechanical instrumentation, several liquid or paste substances are used to ease the action of the files and to eliminate debris and the smear layer. The aim of this study was to evaluate whether the use of a paste containing EDTA during cleaning and shaping of the root canal helps to eliminate debris. METHODS: Twenty root canals in dog teeth were instrumented by a crown-down technique by using nickel-titanium rotary files. In 10 root canals (group A), sodium hypochlorite was used during instrumentation, followed by a final irrigation with 17% liquid EDTA. In another 10 canals (group B), sodium hypochlorite was again used as the irrigating solution, but Glyde File Prep paste was used with every instrument, and a final irrigation with EDTA was also carried out. Two additional teeth were used as positive and 2 as negative controls. The jaws were prepared for histologic evaluation. RESULTS: In group A where Glyde was not used during cleaning and shaping, little or no debris was found in the apical third of the instrumented root canals; however; in group B in which Glyde File Prep paste was used during chemomechanical instrumentation, moderate to high accumulation of debris was observed in the apical third. CONCLUSIONS: The use of Glyde File Prep paste during rotary mechanical instrumentation favors the accumulation of debris in the apical third of the root canals. Irrigation with NaOCl and a final flush with EDTA by means of a small-gauge needle with simultaneous aspiration led to less accumulation of debris than in the Glyde File Prep group (P < .05).

Traditional and contemporary techniques for optimizing root canal irrigation.

UNLABELLED: Canal irrigation during root canal treatment is an important component of chemo-mechanical debridement of the root canal system. Traditional syringe irrigation can be enhanced by activating the irrigant to provide superior cleaning properties. This activation can be achieved by simple modifications in current technique or by contemporary automated devices. Novel techniques are also being developed, such as the Self-adjusting File (Re-Dent-Nova, Ra'anana, Israel), Ozone (Healozone, Dental Ozone, London, UK), Photoactivated Disinfection and Ultraviolet Light Disinfection. This paper reviews the techniques available to enhance traditional syringe irrigation, contemporary irrigation devices and novel techniques, citing their evidence base, advantages and disadvantages. CLINICAL RELEVANCE: Recent advances in irrigation techniques and canal disinfection and debridement are relevant to practitioners carrying out root canal treatment.

Elimination of intracanal tissue and debris through a novel laser-activated system assessed using high-resolution micro-computed tomography: a pilot study.

INTRODUCTION: Laser-activated irrigation to remove organic debris from canal isthmuses was investigated using x-ray microfocus computed tomographic imaging. METHODS: A total of 14 extracted human mandibular molars were used. The mesial canals were prepared using a standardized instrumentation protocol. Two groups (n = 7) underwent final irrigation using either standard needle irrigation (SNI) or photon-induced photoacoustic streaming (PIPS). After enlarging canals to 30/.06, canal volumes were reconstructed from micro-computed tomographic scans before and after irrigation to assess removal of organic tissue and inorganic debris by quantitative analysis of the superimposed volumes. Comparisons of the volumes were made using 2-way analysis of variance and Tukey method, with statistical differences considered significant at the alpha = 0.05 level. RESULTS: Debris removal and an increase in root canal system volume for the laser-activated PIPS group was more significant (P < .001) than for the SNI group (P = .04). Irrigation using PIPS increased the canal volume and eliminated debris from the canal system 2.6 times greater than SNI. CONCLUSIONS: Eliminating debris from complex canal spaces found in mandibular molars was achieved at a significantly greater level using laser-activated PIPS irrigation compared with SNI.

Residual activity of cetrimide and chlorhexidine on Enterococcus faecalis-infected root canals.

Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2% cetrimide, and 0.2% and 2% chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA) to remove the smear layer. The roots were randomly divided into three experimental groups (n=26) according to the final irrigating solution: Group I, 5 mL 0.2% cetrimide; Group II, 5 mL 0.2% chlorhexidine; and Group III, 5 mL 2% chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P<0.05. The highest survival value was found with 2% chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalis growth was detected in 69.23% specimens in Groups I and II, and in 34.61% specimens of Group III. There were no significant differences between 0.2% cetrimide and 0.2% chlorhexidine. Final irrigation with 2% chlorhexidine showed greater residual activity than 0.2% chlorhexidine and 0.2% cetrimide in root canals infected with E. faecalis.

Effect of agitation of EDTA with 808-nanometer diode laser on removal of smear layer.

INTRODUCTION: Near-infrared diode lasers can be used for several applications, which range from disinfection to smear layer removal in endodontics. This study evaluated the efficacy of agitation of 15% EDTA with an 808-nm diode laser on removal of the smear layer. METHODS: Sixty extracted human maxillary central incisor teeth were instrumented up to ProTaper F4 (Dentsply Maillefer, Ballagues, Switzerland) and then randomly divided into 6 groups (n = 10 for each group) according to the different final irrigating protocols as follows: 5% sodium hypochlorite for 120 seconds performed with the NaviTip (Dentsply Maillefer, Ballaigues, Switzerland) (control group); 15% EDTA for 120 seconds performed with the NaviTip; and agitation of 15% EDTA with an 808-nm diode laser for 10, 20, 30, and 40 seconds. Specimens were observed under a scanning electron microscope, and open dentinal tubules were counted using Adobe Photoshop software (Adobe Systems, San Jose, CA). The data were analyzed with 1-way analysis of variance and Tukey post hoc tests (P = .05). RESULTS: The number of open dentinal tubules was higher in the middle thirds than in the apical thirds. The differences between the apical and middle thirds were statistically significant (P < .05). Statistically significant differences were also found between the control group and the other groups in both the middle and apical thirds of the root canals (P < .05). CONCLUSIONS: The results indicated that agitation of 15% EDTA with an 808-nm diode laser for 20 seconds was effective in removing the smear layer in the apical thirds of root canals.