Comparative Analysis of Dentinal Erosion after Passive Ultrasonic Irrigation versus Irrigation with Reciprocating Activation: An Environmental Scanning Electron Study

Introduction

The aim of this study was to assess ex vivo the erosive effects of passive ultrasonic irrigation versus irrigation with reciprocating activation on the dentinal surface of the root canal at 3 predetermined levels using environmental scanning electron microscopy.

Micro-CT evaluation of different final irrigation protocols on the removal of hard-tissue debris from isthmus-containing mesial root of mandibular molars

Objectives

This study aimed to compare four final irrigation protocols (passive ultrasonic irrigation [PUI], EndoVac, Self-Adjusting File [SAF] and EasyClean) on the removal of accumulated hard-tissue debris (AHTD) from mesial canals of mandibular molars through microcomputed tomographic (micro-CT) analysis.

Materials and methods

Forty mesial roots of mandibular molars presenting isthmuses type I or III were scanned in a micro-CT device and instrumented up to Reciproc R40 instrument. After the completion of canal preparations, root canals of each group were submitted to a final rinse using 20 mL of solution (16 mL of 5.25% NaOCl and 4 mL of 17% EDTA) in a total time of 5 min according to one of the four final irrigation protocols (n = 10): PUI, EndoVac, SAF and EasyClean operated at reciprocating motion. The sample was scanned again after canal preparation and after the use of the final irrigation protocols, and the registered data sets were examined to evaluate the percentage of AHTD. Data were statistically compared using the Tukey test with a significance level set at 5%.

Results

All groups presented a decrease on the accumulation of hard-tissue debris after the use of the final irrigation protocols (P < 0.05). No significant differences in the removal of AHTD were observed among the final irrigation protocols (P > 0.05).

Conclusions

All final irrigation protocols showed the same effectiveness in the removal of AHTD. None of them was able to render mesial canals of mandibular molars completely free from packed debris.

Clinical relevance

This study highlighted that all final irrigation protocols (PUI, EndoVac, SAF, and EasyClean) promoted a similar removal of AHTD. However, none of the final irrigation protocols was able to render mesial canals of mandibular molars completely free from packed debris.

     

The Effect of Different Irrigation Agitation Techniques on Postoperative Pain in Mandibular Molar Teeth with Symptomatic Irreversible Pulpitis: A Randomized Clinical Trial

Introduction

This study compared the effect of several final irrigation agitation techniques (sonic agitation, passive ultrasonic irrigation, and manual dynamic agitation [MDA]) in comparison with needle irrigation on postoperative pain in mandibular molar teeth with symptomatic irreversible pulpitis.

Postoperative Pain after Foraminal Enlargement in Anterior Teeth with Necrosis and Apical Periodontitis: A Prospective and Randomized Clinical Trial

IntroductionThe aim of this randomized, controlled, prospective clinical study was to determine if foraminal enlargement instrumentation during endodontic treatment is associated with more postoperative pain compared with standard nonenlargement instrumentation.MethodsForty volunteers with a single root canal were diagnosed with asymptomatic necrosis with apical periodontitis and randomized into 2 experimental groups (ie, the control group and the foraminal enlargement group). Endodontic treatment was performed in a single visit, and volunteers were instructed to record pain intensity (ie, none, slight, moderate, and severe). Scores from 1 to 4 were attributed to each kind of pain after 12, 24, and 48 hours. The Kolmogorov-Smirnov and Student's t tests were used to determine significant differences at P < .05.ResultsNo statistically significant age difference was found between the groups (P > .05, Student's t test). Postoperative pain showed no statistically significant difference between the groups at any observation period (P > .05). Also, no significant difference was observed in the mean number of analgesic tablets used between the groups (P > .05).ConclusionsThe foraminal enlargement and nonenlargement techniques resulted in the same postoperative pain and necessity for analgesic medication. This may suggest that the use of foraminal enlargement should be performed for endodontic treatment previsibility without increasing postoperative pain.     

Evaluation of Passive Ultrasonic Irrigation and GentleWave System as Adjuvants in Endodontic Retreatment

IntroductionNonsurgical endodontic retreatment continues to be a challenge in endodontics, particularly when dealing with a complex tooth anatomy. This study evaluated the efficacy of passive ultrasonic irrigation (PUI) and the GentleWave system as supplementary techniques to remove remaining filling materials from oval-shaped root canals.MethodsTwenty distal roots of human mandibular molars with single and oval-shaped canals were shaped with R40 (40.06) instrument and filled with gutta-percha and AH Plus sealer using warm vertical obturation. Initial filling material removal was performed with R50 (50.05) instrument, followed by the use of PUI (n = 10) or GentleWave system (n = 10). Micro-computed tomographic images were obtained after obturation, initial material removal, and after the use of PUI and GentleWave. The volume of remaining filling material was calculated for the entire canal as well as for the coronal, middle, and apical thirds. Statistical analyses were performed by using analysis of variance, Kruskal-Wallis and Mann-Whitney tests. P ≤ .05 was considered significant.ResultsThe use of PUI and GentleWave as supplementary techniques significantly reduced the volume of remaining filling material after initial instrumentation (P < .05). However, none of these techniques was able to render canals free from filling materials. PUI showed better performance by removing 18% of the remaining filling material, whereas the GentleWave system was able to remove approximately 10% (P = .02).ConclusionsThe use of supplementary techniques optimized filling material removal after initial instrumentation. PUI enhanced the overall cleaning of the root canal system during endodontic retreatment in oval-shaped canals.     

Comparative Antibacterial Efficacies of Hydrodynamic and Ultrasonic Irrigation Systems In Vitro

Introduction

To ensure root canal treatment success, endodontic microbiota should be efficiently reduced. The in vitro bactericidal effects of a hydrodynamic system and a passive ultrasonic irrigation system were compared.

Methods

Single-rooted extracted teeth (n = 250) were contaminated with suspensions of Enterococcus faecalis ATCC 29212, mixed aerobic cultures, or mixed anaerobic cultures. First, the antibacterial effects of the hydrodynamic system (RinsEndo), a passive ultrasonic irrigation system (Piezo smart), and manual rinsing with 0.9% NaCl (the control) were compared. Colony-forming units were counted. Second, the 2 systems were used with 1.5% sodium hypochlorite (NaOCl) alone or NaOCl + 0.2% chlorhexidine (CHX). The colony-forming units in the treated and untreated roots were determined during a period of 5 days.

Results

Both irrigation systems reduced bacterial numbers more effectively than manual rinsing (P < .001). With NaCl, ultrasonic activated irrigation reduced bacterial counts significantly better than hydrodynamic irrigation (P = .042). The NaOCl + CHX combination was more effective than NaOCl alone for both systems (P < .001), but hydrodynamic irrigation was more effective with NaOCl + CHX than the passive ultrasonic irrigation system.

Conclusions

Both irrigation systems, when combined with NaOCl + CHX, removed bacteria from root canals.     

Wall shear stress effects of different endodontic irrigation techniques and systems

ObjectivesThis study examined débridement efficacy as a result of wall shear stresses created by different irrigant delivery/agitation techniques in an inaccessible recess of a curved root canal model.MethodsA reusable, curved canal cavity containing a simulated canal fin was milled into mirrored titanium blocks. Calcium hydroxide (Ca(OH)₂) paste was used as debris and loaded into the canal fin. The titanium blocks were bolted together to provide a fluid-tight seal. Sodium hypochlorite was delivered at a previously-determined flow rate of 1 mL/min that produced either negligible or no irrigant extrusion pressure into the periapex for all the techniques examined. Nine irrigation delivery/agitation techniques were examined: NaviTip passive irrigation control, Max-i-Probe^® side-vented needle passive irrigation, manual dynamic agitation (MDA) using non-fitting and well-fitting gutta-percha points, EndoActivator™ sonic agitation with medium and large points, VPro™ EndoSafe™ irrigation system, VPro™ StreamClean™ continuous ultrasonic irrigation and EndoVac apical negative pressure irrigation. Débridement efficacies were analysed with Kruskal–Wallis ANOVA and Dunn's multiple comparisons tests (α = 0.05).ResultsEndoVac was the only technique that removed more than 99% calcium hydroxide debris from the canal fin at the predefined flow rate. This group was significantly different (p < 0.05) from the other groups that exhibited incomplete Ca(OH)₂ removal.ConclusionsThe ability of the EndoVac system to significantly clean more debris from a mechanically inaccessible recess of the model curved root canal may be caused by robust bubble formation during irrigant delivery, creating higher wall shear stresses by a two-phase air–liquid flow phenomenon that is well known in other industrial débridement systems.     

Effect of Diclofenac Potassium Premedication on Postendodontic Pain in Mandibular Molars with Symptomatic Irreversible Pulpitis: A Randomized Placebo-Controlled Double-Blind Trial

IntroductionThe aim of this prospective, randomized, double-blind clinical trial was to evaluate the effect of a preoperative, single, oral dose of diclofenac potassium (DFK) on postoperative pain and rescue analgesic intake in patients with symptomatic irreversible pulpitis in mandibular molars treated in 1 visit.MethodsSeventy emergency patients with moderate to severe preoperative pain randomly received either 50 mg DFK or placebo tablets 1 hour before starting endodontic treatment (n = 35 per group). Patients recorded their pain level 6, 12, 24, and 48 hours after treatment on a 170-mm Heft-Parker visual analog scale. The incidence of rescue analgesic intake was also recorded. Outcome data were statistically analyzed using Mann-Whitney U, Friedman, Wilcoxon signed rank, and chi-square tests. Binary logistic regression assessed the association of predisposing factors with postoperative pain. The significance level (α) was set at 0.05.ResultsOf the 70 patients, 68 were analyzed (n = 34 per group). Both groups had similar baseline characteristics (P > .05). DFK showed significantly less pain incidence and intensity than the placebo at 48 hours only (P < .05). A significant decrease occurred from 24 to 48 hours with DFK (P < .05), which was not recorded with the placebo (P > .05). No difference in the incidence of rescue analgesic intake was reported between groups (P > .05). Food intake timing, sex, and rescue analgesic intake were associated with postoperative pain (P < .05).ConclusionsPremedication by a single, oral dose of 50 mg DFK could be effective in reducing postendodontic pain at 48 hours after 1-visit endodontic treatment in mandibular molars with symptomatic irreversible pulpitis.     

The effect of sonic activation of irrigant on postoperative pain after root canal treatment in primary molar teeth: a randomized,clinical study

Purpose

Postoperative pain following root canal treatment is a concern for pediatric patients and pediatric dentists. The purpose of this study was to evaluate the effect of using sonic activation (SA) on postoperative pain levels after root canal therapy of primary molars.

Methods

A total of 110 patients aged 5–9 years with symptomatic irreversible pulpitis involving primary molars were included in the study and were randomly divided into two groups according to agitation methods: SA and no sonic activation (NSA). Root canal treatments were completed, and the teeth were restored permanently. Postoperative pain levels were evaluated using the five-face scale at 8, 24, 48, and 72 h and 1 week after treatment. Pain levels and frequency of analgesic intake were recorded and analyzed.

Results

Postoperative pain values were lower in the SA group than in the NSA group at 8, 24, and 48 h after treatment (p < 0.05). No significant difference was observed between the groups in terms of postoperative pain values at 72 h and 1 week after treatment (p > 0.05).

Conclusions

It was determined that the use of SA reduces postoperative pain level significantly after root canal treatment in primary molar teeth.

Clinical relevance

The use of SA can be recommended to clinicians since it is effective in the successful management of postoperative pain of root canal treatment in primary molar teeth.

Trial registration

ClinicalTrials.gov ID: NCT04197531

     

Irrigant flow during photon-induced photoacoustic streaming (PIPS) using Particle Image Velocimetry (PIV)

Objectives

This study aimed to compare fluid movements generated from photon-induced photoacoustic streaming (PIPS) and passive ultrasonic irrigation (PUI).

Materials and methods

Particle Image Velocimetry (PIV) was performed using 6-μm melamine spheres in water. Measurement areas were 3-mm-long sections of the canal in the coronal, midroot and apical regions for PIPS (erbium/yttrium-aluminium garnet (Er:YAG) laser set at 15 Hz with 20 mJ), or passive ultrasonic irrigation (PUI, non-cutting insert at 30 % unit power) was performed in simulated root canals prepared to an apical size #30/0.04 taper. Fluid movement was analysed directly subjacent to the apical ends of ultrasonic insert or fiber optic tips as well as at midroot and apically.

Results

During PUI, measured average velocities were around 0.03 m/s in the immediate vicinity of the sides and tip of the ultrasonic file. Speeds decayed to non-measureable values at a distance of about 2 mm from the sides and tip. During PIPS, typical average speeds were about ten times higher than those measured for PUI, and they were measured throughout the length of the canal, at distances up to 20 mm away.

Conclusions

PIPS caused higher average fluid speeds when compared to PUI, both close and distant from the instrument. The findings of this study could be relevant to the debriding and disinfecting stage of endodontic therapy.

Clinical relevance

Irrigation enhancement beyond needle irrigation is relevant to more effectively eradicate microorganisms from root canal systems. PIPS may be an alternative approach due to its ability to create high streaming velocities further away from the activation source compared to ultrasonic activation.

     

Comparative Evaluation of Calcium Hypochlorite and Sodium Hypochlorite Associated with Passive Ultrasonic Irrigation on Antimicrobial Activity of a Root Canal System Infected with Enterococcus faecalis: An In Vitro Study

Introduction

The purpose of this study was to compare in vitro the effectiveness of calcium hypochlorite (Ca[OCl]₂) and sodium hypochlorite (NaOCl) associated with passive ultrasonic irrigation in root canals of bovine teeth infected with Enterococcus faecalis.

Methods

The root canals of 60 single-rooted bovine extracted teeth were enlarged up to a file 45, autoclaved, inoculated with Enterococcus faecalis, and incubated for 30 days. The samples were divided into 6 groups (n = 10) according to the protocol for decontamination: G1: no treatment; G2: distilled water; G3: 2.5% NaOCl; G4: 2.5% Ca(OCl)₂; G5: 2.5% NaOCl with ultrasonic activation; and G6: 2.5% Ca(OCl)₂ with ultrasonic activation (US). Microbiological testing (colony-forming unit [CFU] counting) was performed to evaluate and show, respectively, the effectiveness of the proposed treatments. Data were subjected to 1-way analysis of variance followed by the post hoc Tukey test (α = 0.05).

Results

Groups 1 and 2 showed the highest mean contamination (3.26 log₁₀ CFU/mL and 2.69 log₁₀ CFU/mL, respectively), which was statistically different from all other groups (P < .05). Group 6 (Ca[OCl]₂ + US) showed the lowest mean contamination (1.00 log₁₀ CFU/mL), with no statistically significant difference found in groups 3 (NaOCl), 4 (Ca[OCl]₂), and 5 (NaOCl + US) (P < .05).

Conclusions

Ca(OCl)₂ as well as passive ultrasonic irrigation can aid in chemomechanical preparation, contributing in a significant way to the reduction of microbial content during root canal treatment.     

Postoperative Pain after Treatment Using the GentleWave System: A Randomized Controlled Trial

IntroductionCleaning and shaping are necessary to allow for the delivery of irrigants and medicaments to the apical third of the canal. Standard treatment irrigation generally uses a conventional needle and some frequency of sonic activation. The GentleWave System (GWS; Sonendo, Inc, Laguna Hills, CA) combines irrigant delivery with multisonic activation. This randomized clinical trial aimed to determine if the GWS significantly decreases the incidence and intensity of postoperative pain.MethodsPatients used a numeric rating scale to record their pain level at the 6-hour time point before treatment. All participants were randomly divided into 2 groups and were blind to the treatment they received. The standard (control) group received endodontic treatment with conventional side-vented needle irrigation and ultrasonic activation. The second group received treatment with the GWS. Following treatment, patients used a numeric rating scale to record their pain level at 6, 24, 72, and 168 hours.ResultsIn the standard treatment group, 72.2% of patients experienced at least 1 occurrence of postoperative pain, whereas in the GWS group, 83.3% of patients experienced at least 1 occurrence of postoperative pain. The highest pain intensity level for both treatments occurred at the 6-hour posttreatment time point. All pain decreased with time after the 6-hour posttreatment time point (P < 1.237e⁻⁷).ConclusionsThere was no significant difference in the incidence or intensity of postoperative pain after either treatment group. However, both groups reported a statistically significant decrease in pain with time.     

Intracanal Cryotherapy Reduces Postoperative Pain in Teeth with Symptomatic Apical Periodontitis: A Randomized Multicenter Clinical Trial

Introduction

A prospective, multicentered, randomized clinical trial was designed to assess if controlled irrigation with cold saline could result in less incidence and intensity of postoperative pain in patients presenting with pulp necrosis and symptomatic apical periodontitis.

Postoperative endodontic pain of three different instrumentation techniques in asymptomatic necrotic mandibular molars with periapical lesion: a prospective,randomized, double-blind clinical trial

Objectives

The purpose of this prospective, randomized, double-blind study was to compare postoperative pain of root canal treatment in patients with asymptomatic mandibular molar teeth with necrotic pulp and periapical lesion using three different instrumentation techniques: hand, multi-file rotary (ProTaper Universal), and reciprocating single-file (Wave-One) instrumentation techniques.

Materials and methods

Ninety-six patients who fulfilled specific inclusion criteria were assigned to three groups according to the root canal instrumentation technique used: Hand (G1), ProTaper Universal (G2), and Wave-One (G3). One-visit root canal treatment was carried out, and the severity of the postoperative pain was assessed by the Heft-Parker visual analogue scale 6, 12, 18, 24, 48, and 72 h after treatment. Data were analyzed by Kruskal-Wallis, χ ², Cochrane Q, one-way ANOVA, and Spearman’s correlation analyses (α = 0.05).

Results

The patients in group 3 reported significantly lower postoperative pain levels at 6, 12, and 18 h compared with the patients in the two other groups (P < .05). In addition, the patients in group 2 reported significantly lower postoperative pain levels at 6 and 12 h compared with the patients in group 1 (P < .05). There were no significant differences in postoperative pain between the three groups at other time intervals (P > .05). The analgesic consumption was significantly higher in group 1 (P < .05), but no difference was seen between the two other groups (P > .05).

Clinical relevance

Postoperative pain was significantly lower in patients undergoing root canal instrumentation with the Wave-One file compared with the ProTaper Universal and hand files.

     

Spectrophotometric Determination of Irrigant Extrusion Using Passive Ultrasonic Irrigation,EndoActivator, or Syringe Irrigation

Introduction

Sodium hypochlorite (NaOCl) irrigation is critical to endodontic success, and several new methods have been developed to improve irrigation efficacy (eg, passive ultrasonic irrigation [PUI] and EndoActivator [EA]). Using a novel spectrophotometric method, this study evaluated NaOCl irrigant extrusion during canal irrigation.

Methods

One hundred fourteen single-rooted extracted teeth were decoronated to leave 15 mm of the root length for each tooth. Cleaning and shaping of the teeth were completed using standardized hand and rotary instrumentation to an apical file size #40/0.04 taper. Roots were sealed (not apex), and 54 straight roots (n = 18/group) and 60 curved roots (>20° curvature, n = 20/group) were included. Teeth were irrigated with 5.25% NaOCl by 1 of 3 methods: passive irrigation with needle, PUI, or EA irrigation. Extrusion of NaOCl was evaluated using a pH indicator and a spectrophotometer. Standard curves were prepared with known amounts of irrigant to quantify amounts in unknown samples.

Results

Irrigant extrusion was minimal with all methods, with most teeth showing no NaOCl extrusion in straight or curved roots. Minor NaOCl extrusion (1–3 μL) in straight roots or curved roots occurred in 10%–11% of teeth in all 3 irrigant methods. Two teeth in both the syringe irrigation and the EA group extruded 3–10 μL of NaOCl.

Conclusions

The spectrophotometric method used in this study proved to be very sensitive while providing quantification of the irrigant levels extruded. Using the PUI or EA tip to within 1 mm of the working length appears to be fairly safe, but apical anatomy can vary in teeth to allow extrusion of irrigant.     

Evaluation of Ozone Therapy in Endodontic Treatment of Teeth with Necrotic Pulp and Apical Periodontitis: A Randomized Clinical Trial

IntroductionThe aim of this study was to compare the effect of different application techniques of ozone on the prevalence of postendodontic pain in patients undergoing single-visit root canal treatment.Methodshundred eight patients with necrotic pulp in single-rooted teeth and apical periodontitis participated in the trial. A standard single-visit endodontics protocol was followed with 5.25% sodium hypochlorite and rotary nickel-titanium files. After shaping and cleaning, patients were randomly allocated into the following groups: group 1 (n = 21), ozone treatment with no activation (NA); group 2 (n = 22), ozone treatment with manual dynamic activation (MDA); group 3, (n = 21), ozone treatment with passive ultrasonic activation (PUA); group 4 (n = 23), ozone treatment with sonic activation (SA); and group 5 (n = 21), no ozone treatment (the control group). Patient levels of discomfort were recorded at 6 different time intervals using the visual analog scale (VAS). Comparison of the mean difference between the groups and time intervals was performed using 2-way analysis of variance followed by a post hoc Bonferroni test. The level of significance was set at 5%.ResultsVAS scores were highest for the control > NA > MDA > SA > PUA groups. A statistically significant reduction in VAS scores was observed in the PUA and SA groups in comparison with the NA, control, and MDA groups. Timewise comparison showed a highly significant decline in VAS scores at all time intervals (P < .001).ConclusionsUltrasonic and sonic activation of ozone resulted in less pain in patients undergoing single-visit endodontics compared with no ozone treatment.     

An In Vitro Comparison of New Irrigation and Agitation Techniques to Ultrasonic Agitation in Removing Bacteria From a Simulated Root Canal

IntroductionThis in vitro study compared 3 agitation and 2 irrigation devices to ultrasonic agitation at mechanically removing bacteria from a plastic simulated canal, instrumented to 35/.06.MethodsThe plastic blocks were divided into seven groups. The control (C) group with brain-heart infusion (BHI) broth (sterile) received only needle irrigation. The remaining groups were incubated with BHI inoculated with Enterococcus faecalis. Irrigation and agitation techniques were ultrasonic, needle irrigation, EndoVac irrigation (Smart Endodontics; Discus Dental, Culver City, CA), EndoActivator (Dentsply Tulsa Dental Specialties, Tulsa, OK), F-File (Plastic Endo, Lincolnshire, IL), and sonic. Sterile water was the irrigant in all treatments. Remaining bacteria were stained with 0.1% crystal violet. The crystal violet was extracted using a detergent and measured spectrophotometrically.ResultsThe results of this study show that ultrasonic agitation was not significantly different (p > 0.05, Tukey test) from the control. There was no significant difference (p > 0.05, Tukey test) between the ultrasonic agitation and the use of EndoActivator, F-File, and sonic agitation. Ultrasonic agitation was significantly more effective at removing bacteria than needle irrigation and EndoVac irrigation (p < 0.05, Tukey test).ConclusionIn a plastic simulated canal, ultrasonic agitation was significantly more effective than needle irrigation and EndoVac irrigation at removing intracanal bacteria. Ultrasonic, EndoActivator, F-File, and sonic agitation are similar in their ability to remove bacteria in a plastic simulated canal.     

Comparative Evaluation of Canal Isthmus Debridement Efficacy of Modified EndoVac Technique with Different Irrigation Systems

Introduction

The purpose of this study was to evaluate the canal isthmus debridement efficacy of a new modified EndoVac (Discus Dental, Culver City, CA) irrigation protocol in comparison with EndoVac, passive ultrasonic irrigation (PUI), and conventional needle irrigation in mesial roots of mandibular molars.

Methods

The mesial roots of 64 extracted mandibular molars mounted in resin using Kuttler's endodontic cube, sectioned at 2 and 4 mm from the working length, were randomly divided into 4 groups (n = 16): group 1: Max-I-Probe (Dentsply Tulsa Dental, York, PA), group 2: EndoVac (EVI), group 3: modified EndoVac, and group 4: PUI. The specimens were reassembled and instrumented. A standard irrigation protocol was used during cleaning and shaping and final irrigation with the 4 irrigation/agitation techniques. Images of the isthmus region were taken before and after cleaning and shaping and after final irrigation. The percentage reduction of debris in the isthmus region was calculated by using the software program Image J (v1.43; National Institutes of Health, Bethesda, MD). Intergroup analysis was performed using the Kruskal Wallis and Mann-Whitney U tests. Intragroup analysis was performed using Friedman and Wilcoxon signed rank tests. The level of significance was set at P < .05.

Results

Intragroup analysis revealed a statistically significant difference in the percentage reduction of debris after cleaning and shaping and after final irrigation protocol in all the groups (P < .001). The final irrigation protocol produced significantly cleaner canal isthmuses in all the groups (P < .001). On intergroup analysis, the modified EVI group performed significantly better than the other groups. The EVI and PUI groups performed better than the Max-I-Probe group. There was no statistical significance between the EVI and PUI groups.

Conclusions

Canal isthmuses were significantly cleaner with the modified EndoVac irrigation technique when compared with the cleanliness seen with the other irrigation systems.     

Impact of Sodium Hypochlorite on Organic Tissue Dissolution in the Periapical Region of Immature Permanent Teeth: An Ex Vivo Study

IntroductionThe purpose of this study was to evaluate the impact of different sodium hypochlorite (NaOCl) irrigation protocols on organic tissue dissolution in the periapical region of simulated immature permanent teeth.MethodsEight single-rooted premolars and 48 samples of porcine palatal mucosa were used. Acrylic resin prototypes were constructed, placing the tissue in close contact with the dental apices. Specimens were then divided into 6 groups (n = 8): 2 control groups of normal saline irrigation with (NS/WA) or without (NS/NA) ultrasonic activation and 4 experimental groups of 1.5% and 2.5% NaOCl irrigation with (NaOCl 1.5%/WA and NaOCl 2.5%/WA) or without (NaOCl 1.5%/NA and NaOCl 2.5%/NA) activation. Root canals were irrigated with 20 mL of the solution for 5 minutes distributed over 4 irrigation cycles. In each cycle, after irrigation, the solution was either kept stagnant or activated for 30 seconds and then replaced. Specimens were weighed on a precision balance before and after the irrigation protocols. Tissue dissolution was measured by the difference between the initial and final weights. One-way analysis of variance was applied followed by the Tukey honestly significant difference test (α = 0.05).ResultsThe NS/NA and NS/WA groups had mean weight reductions similar to the 1.5% NaOCl/NA group (P > .05) and lower than the others (P < .05). The 2.5% NaOCl/NA and 2.5% NaOCl/WA groups had the highest mean weight loss (P < .05), whereas the 1.5% NaOCl/WA group had intermediate values (P < .05).ConclusionsPeriapical tissue dissolution occurred in all groups, with a greater impact observed with 2.5% NaOCl with or without ultrasonic activation.