Nonsurgical Endodontic Retreatment Research Articles

Factors Influencing Quality of Life after Surgical and Nonsurgical Interventions of Persistent Endodontic Disease

IntroductionNonsurgical endodontic retreatment and apical surgery are predictable procedures for the management of endodontically treated teeth with persistent disease. However, there is no information available that compares these treatment modalities based on patients’ oral health–related quality of life (OHRQOL). The aims of this study were to compare the OHRQOL of patients who received nonsurgical endodontic retreatment versus those who received apical surgery and to identify correlations between OHRQOL, clinician-assessed healing outcome, and other factors. MethodsPatients who received treatment at 2 dental hospitals with a recall period of 6–24 months were invited to participate. They underwent follow-up examination and were surveyed with the Oral Health Impact Profile (OHIP-14). Healing outcomes were determined by clinical and radiographic evaluation. Potential influencing factors for OHIP-14 scores were investigated. ResultsOne hundred fifty patients (75 patients from each group) participated in the study. There were no differences in OHIP-14 scores between both groups at the follow-up. The overall adverse impact on OHRQOL was low, with patients experiencing greater impact in the domains of “physical pain” and “psychological discomfort.” Women and patients who had preoperative pain reported a greater impact. There was an overall high healed and healing rate for both groups. No correlation was found between OHIP-14 scores and healing outcome. ConclusionsPatients who received nonsurgical endodontic retreatment and apical surgery reported comparable OHRQOL, with women and patients with preoperative pain reporting greater impact. Both treatments are viable options for the management of persistent endodontic disease based on clinician- and patient-reported outcome assessments.

Retreatability of Bioceramic Endodontic Sealers: a Review.

In 2009 a new type of endodontic sealers was introduced to the market. The so called "bioceramic" sealers are a promising alternative to the present golden standard of root canal fillings. Now a decade later, still very little is known about the ability to remove these sealers in cases of non-surgical endodontic retreatment (NSER). There are only a limited number of articles that provide such information. The commonly used hand files are not efficient in removing thoroughly the sealer from the main canal walls. Machine driven files are much easier and faster alternative to the hand ones, but are still not able to ensure complete removal. Although ultrasonics can be applied only in the straight portion of the main canal, they raise the efficacy of sealer removal. Photon-initiated photoacoustic streaming (PIPS) is another way to enhance the removal of bioceramics. Solvents like chloroform and orange oil are effective in softening gutta-percha, but not the bioceramics. This article reviews the available scientific data concerning removal of bioceramic materials in the context of a NSER.

The Efficacy of Rotary, Reciprocating, and Combined Non-Surgical Endodontic Retreatment Techniques in Removing a Carrier-Based Root Canal Filling Material from Straight Root Canal Systems: A Micro-Computed Tomography Analysis.

The aim of this study is to analyze and compare the efficacy of three non-surgical endodontic retreatment techniques in removing a carrier-based root canal filling material from straight root canal systems. The study was performed on 99 single-rooted extracted teeth using the ProTaper Gold endodontic rotary system up to the F2 file (Dentsply Maillefer, Baillagues, Switzerland), which were sealed with GuttaCore (Dentsply Maillefer, Ballaigues, Switzerland) and AH plus epoxy resin sealer (Dentsply DeTrey, Konstanz, Germany) and randomly assigned to the following non-surgical retreatment techniques: ProTaper Retreatment endodontic rotary instruments (D1–D3 files, Dentsply Maillefer, Ballaigues, Switzerland; n = 33, PTR), Reciproc Blue endodontic reciprocating instrument (R50, VDW, Munich, Germany; n = 33, RCB50), and a combined root canal retreatment technique between Gates-Glidden drills (sizes #3 and #2, Dentsply Maillefer, Ballaigues, Switzerland) and Hedstrom files (file size 35, 30, and 25, Dentsply Maillefer, Ballaigues, Switzerland; n = 33; H-GG). All of the teeth were submitted twice to a micro-computed tomography (micro-CT) scan, before and after non-surgical endodontic retreatment procedures. The volume of root canal filling material (mm3), volume of remaining root canal filling material (mm3), non-surgical endodontic retreatment working time (min), proportion of remaining root canal filling material (%), and efficacy of root canal filling material removal between the non-surgical endodontic retreatment techniques were analyzed using ANOVA one-way statistical analysis. Statistically significant differences were observed between the proportions of remaining root canal filling material of PTR and H-GG (p = 0.018), between the non-surgical endodontic retreatment working times (min; p < 0.001), and between the efficacies of root canal filling material removal by the non-surgical endodontic retreatment techniques (p = 0.009). However, the non-surgical endodontic retreatment systems allow for similar carrier-based root canal filling material removal.

Retreatability of BC Sealer and AH Plus root canal sealers using new supplementary instrumentation protocol during non-surgical endodontic retreatment.

The aim of this study was to evaluate the efficacy of supplementary techniques (ultrasonic tip/XP-endo Finisher R) in removing remaining filling materials (gutta-percha/AHPlus/BCSealer) from oval-shaped root canals during non-surgical endodontic retreatment. Twenty-eight distal roots of human mandibular molars with single and oval-shaped canals were initially shaped with a R40 instrument and filled with gutta-percha points and AH Plus (n= 14) or BC Sealer (n= 14) followed by an initial micro-CT scanning. Initial filling material removal was performed in all 28 samples with an R50 instrument, and all samples submitted to a second micro-CT. Supplementary techniques with ultrasonic tips or XP-endo Finisher R instruments were performed in each sealer group, and all samples submitted to a third micro-CT. 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 using T, ANOVA 3-way, and Tukey tests. Lower values of remnant filling material were found for BC Sealer (16.06 ± 14.34) compared to AH Plus (28.30 ± 10.54) (P < 0.001), and considering the supplementary technique, lower values of remnant filling material were found for the ultrasonic tip (18.95 ± 11.05) compared to XP-endo Finisher R (25.41 ± 15.81) (P = 0.025). Ultrasonic instruments significantly reduced the percentage of remaining filling material for both AH Plus (P = 0.04) and BC Sealer (P = 0.02) while XP-endo Finisher R was effective for AHPlus only (P = 0.04). The remaining filling material was observed in all samples regardless the filling material or the supplementary technique employed. Supplementary techniques increased filling material removal; however, none of them was able to render root canals completely free from root fillings. Ultrasonic tips should be considered a good option for endodontic retreatment, especially for bioceramic cases. Supplementary instrumentation techniques are effective tools to reduce the amount of filling materials during root canal retreatment.

Decision making process by senior residents of Saudi Board in restorative dentistry for nonsurgical endodontic retreatment: A retrospective study

BackgroundDespite the general guidelines for retreatment, differences in decision making exist for secondary endodontic treatment and may be related to many factors including education, clinical experience, dentist specialty, patient preferences and economic resources. Aim of the study was to evaluate the decision making of the Saudi Board in Restorative Dentistry (SBRD) senior residents in the endodontic retreatment of molar teeth as per the scientific guidelines of the American Association of Endodontists (AAE) and also to identify the causes of retreatment and measure how far they become deviated from their taught retreatment principles and inter-individual variability. Materials and methodsCase histories have been obtained from the files of cases treated in the SBRD Resident Comprehensive Case Archives in the SCHS from 2003 to 2015 in Riyadh region. The cases were only confined to Complex I and Complex II cases according to RDITN (Restorative Dental Index of Treatment Need), and seen by R3 and R4 residents only. Residents’ diagnosis was recorded as well as their treatment plan and any given notes regarding their decisions to retreat. Differences between the two groups (R3 and R4) residents and within the same group, regarding endodontic retreatment decisions and reasons for their treatment options were analyzed using Chi-Square test and Fisher’s Exact test. ResultsThe majority of residents in both R4 and R3 groups followed the recommended guidelines. R3 residents preferred to retreat all cases while R4 chose ‘no to retreat’ in few cases. Although R4 residents preferred nonsurgical retreatment more than R3 residents, the difference was insignificant. R4 residents preferred ‘no therapy’ or ‘follow up’ more frequent than R3 residents. Members of the R3 residents agreed more or less with each other as did those of the R4 residents without significant inter-individual variations within each group regarding the choice of retreatment). ConclusionsR4 residents appeared more likely, although not significant, to choose no retreatment or follow up than R3 residents. Conventional nonsurgical retreatment had the highest selection by both R3 and R4 residents. No significant inter-individual variations within each group regarding the choice of retreatment. There is a need to establish evidence based guidelines for more uniform management of failed root treated teeth.

Application of Cutting-Tool Concepts to Endodontic Files to Achieve Better Design: A Review

Cutting efficiency of endodontic files (EFs) has been widely evaluated in the literature. However, its performance depends on the microgeometry of the cutting instrument itself, and this has not been studied in depth. The present review describes basic concepts of cutting instruments, including cutting-tool engineering, the EF relationship, and cutting efficiency among different EF geometric designs during primary treatment and nonsurgical endodontic retreatment.

Comparative evaluation of retreatment techniques by using different file systems from oval-shaped canals.

Introduction:Endodontic failure resolves after complete removal of obturating material followed by disinfection, cleaning, shaping and three-dimensional obturation.Materials and Methods:Seventy single-rooted mandibular premolars, with single oval-shaped root canal were included. They were decoronated at a length of 16 mm from the apex. Shaping and cleaning were performed, and obturation was done using the warm lateral compaction technique. The teeth were divided into seven groups according to retreatment procedures (Hand files; ProTaper Universal retreatment files; MTwo® Retreatment system; R-Endo® Retreatment system; ProTaper Universal retreatment files with solvent and ultrasonics; MTwo® R with solvent, and ultrasonics and R-Endo® with solvent and ultrasonics). The data were obtained and subjected to the statistical analysis.Results:All instrumentation techniques left obturating material with least in Group 6 and maximum Group 5. The mean time taken for complete retreatment procedure was minimum in Group 2 and maximum with Group 1.Conclusion:MTwo® R with solvent and ultrasonics, R-Endo®, and R-Endo® with solvent and ultrasonics were effective in gutta-percha removal from coronal third, middle third, and apical third, respectively. Significance: Nonsurgical endodontic retreatment using rotary files helps in gaining access to infected teeth. During retreatment procedure, this helps disinfectant to reach in critical areas of the root canal system, thereby decreasing the microbial load, leading to achieve healthy periradicular tissues.

Effect of Rotary and Reciprocating Instrumentation Motions on Postoperative Pain Incidence in Non-Surgical Endodontic Treatments: A Systematic Review and Meta-Analysis.

Objective:A systematic review and meta-analysis were conducted to determine whether there are postoperative pain differences resulting from rotary and reciprocation engine-driven instrumentation motions in non-surgical endodontic treatment or retreatment at 12, 24, and 48 hours.Methods:Four electronic databases (PubMed, Embase, Cochrane Library, and Scopus) were searched to identify randomised controlled trials that compared the effects of rotary and reciprocating instrumentation motions on postoperative pain. Two authors independently screened the search results, extracted the data, and assessed the quality using the Cochrane risk of bias tool. Due to numerous variables across studies, the random effect inverse variance method for meta-analysis was applied. When significant heterogeneity among studies was present, the random effects multi-variable meta-regression analysis was performed to determine the source of heterogeneity.Results:At all time intervals, the incidence of postoperative pain was higher in the reciprocating instrumentation group, but was not statistically significant. There was no significant difference in the analgesic intake between groups. Meta-regression analysis determined study population sizes as a significant heterogeneous factor, while significance was not observed for preoperative pain or the pulpal diagnosis.Conclusion:There was no difference in postoperative pain at 12, 24, and 48 hours after non-surgical root canal treatment and retreatment, using reciprocating or rotary instrumentation motions.

Removal of Obturation Material from Root Canals Using a Combination of Reciprocal Instrumentation and Different Final Irrigation Techniques.

The predictability of successful non-surgical endodontic retreatment is directly related to it's ability to completely cleanse and remove obturation material from the canal system. The purpose of this study was to evaluate the removal of gutta-percha from curved canals using three final irrigation methods: passive ultrasonic irrigation (PUI) with a 20/01 E1 insert (Irrisonic); XP-endo Finisher (XPF); and Easy Clean (EC). Forty mesial roots of mandibular molars with an angle of curvature between 10° and 20°, two canals, and independent foramina were cut into 16-mm sections. The canals were instrumented using the Reciproc system (R25) and filled with a #25 gutta-percha cone and AH-Plus sealer by the continuous-wave condensation technique. The roots were double-sealed with Coltosol and photopolymerizable resin and stored at 37°C and 100% humidity for 30 days. They were then randomized into 4 groups (n=10): control (C), PUI, XPF, and EC. All specimens were scanned using cone-beam computed tomography (CBCT), and fill volume data (in square pixels) were calculated before retreatment, after retreatment, and after final irrigation. The images were analyzed using Tps Dig software 2.32 by two blinded, calibrated examiners (intra-class correlation coefficient=0.9967). The results were analyzed in BioEstat 4.0. The nonparametric Kruskal-Wallis test with Dunn's post-hoc and Friedman comparison were applied. Significance was accepted at 5% (P<0.05). None of the final irrigation protocols completely removed remnants of obturation material from the root canal systems (P>0.05). On comparative analysis with specimens divided into thirds, all methods were found to remove material equally, with no significant differences (P>0.05). Based on this in vitro study, the additional cleaning methods tested were equivalent to each other and did not lead to an improvement in the removal of residual obturation material.

Non-surgical Endodontic Retreatment in Periapical Abscess: A Case Report

Endodontic failure affects the teeth and surrounding tissues. This is a case of a 62-year-old female with a chief complaint of pain and swelling occurring frequently in the upper left teeth for 6 months. The tooth was treated a year ago. Nonsurgical endodontic retreatment was carried out and observed for 4 months. The size of the lesion reduced significantly during the healing evaluation. This case report aimed to show the management of a non-surgery endodontic retreatment in periapical abscess using a rotary instrument.

Non-surgical endodontic retreatment of extra-oral cutaneous sinus using propolis as an intracanal medicament: A case report

This case report describes a successful non-surgical endodontic retreatment of the lower right central incisor with periapical lesion with tender extra-oral cutaneous sinus at the mental region. The extra-oral cutaneous sinus was misdiagnosed as acne & was treated by a skin specialist. The tooth underwent root canal treatment in which Indian Propolis was used as an intracanal medicament. The tooth was obturated after 7 months after initiation of therapy. At 12 months recall intraoral periapical radiograph showed healing of the periapical lesion & the extra-oral cutaneous sinus was healed with scarring. A thorough clinical evaluation, proper diagnosis and multidisciplinary treatment protocol are important for the success of the treatment. This paper suggest that Indian Propolis was effective in the healing of periapical lesion with extra oral sinus. Keywords: Extra-oral sinus, Indian Propolis, Intracanal medicament & Periapical lesion

Evaluation Of Postoperative Pain After Using Sonic Vibringe Irrigation System Versus Conventional syringe irrigation In Single Rooted Teeth With Symptomatic Irreversible Pulpitis : A Randomized Clinical Controlled Trial

Aim: The aim of this study was to clinically compare the postoperative pain after Vibringe sonic irrigation system and conventional needle irrigation during root canal treatment in single-rooted teeth . Methods: A total of 18 patients with symptomatic irreversible pulpitis in need of nonsurgical endodontic retreatment were randomly divided into 2 groups (n = 9) . Patients were carefully diagnosed and checked for the eligibility criteria . Irrigation in (group A) was delivered and sonically activated by Vibringe and Irrigation in (group B) was done using conventional needle. The presence of postoperative pain was assessed 6, 12, 24, and 48 hours after treatment according to the NRS where; 0; No pain, 1-3; mild pain, 4-6; moderate pain, 7-10; severe pain “severe pain, analgesic had no effect in relieving the pain”. Data were analyzed using the Mann-Whitney U,Friedman’s test, and Fisher’s Exact tests. Results: Postoperative pain was non significantly different in the Vibringe group in comparison with the conventional needle group (P >.05) on all time intervals “ 6 -12-24 and 48 hours” (P-value = 0.753) . Pain scores from base line to 6 hours post-operatively showed statistically significant decrease in both Vibringe and Conventional needle irrigation group (P-value <0.001). Conclusions: The sonically activated Vibringe irrigation system and conventional needle irrigation are equally safe with low incidence of post-operative at 6, 12 , 24 and 48 hours intervals.

Comparative Evaluation of Retreatability of Endodontically Treated Teeth using AH 26, Fluoride Varnish and Mineral Trioxide Aggregate-based Endodontic Sealers

Background and Objectives:Endodontic sealers are used to fill the gap between the root filling material and canal walls. Retrievability is an important requirement for sealers and root filling materials in non-surgical endodontic retreatment. This study sought to assess the retreatability of fluoride varnish, AH 26 and Mineral Trioxide Aggregate (MTA)-based sealers using Cone-Beam Computed Tomography (CBCT).Materials and Methods:Thisin vitro, experimental study evaluated 45 extracted single-rooted, single-canal human mandibular premolars. Teeth with cracks or fracture were excluded. The root canals were prepared using ProTaper Universal rotary system up to size F4 according to the manufacturer’s instructions. The teeth were then randomly divided into three groups of 5% fluoride varnish, AH 26 and MTA Fillapex. CBCT scans were obtained of the teeth with 200 μm voxel size. MATLAB R2012 software was used to quantify the amount of sealer remaining in the canal. Two observers evaluated the images. Data were analyzed using SPSSviathe Kruskal-Wallis and Mann Whitney tests.Results:The amount of sealer remaining in the root canals was significantly different among the three groups (P&lt;0.05). The amount of AH 26 sealer remaining in the root canals (1.91±1.46) was significantly greater than MTA Fillapex (0.62±0.26) and fluoride varnish, but the latter two were not significantly different in this respect (P&gt;0.05).Conclusion:Considering the adequate adhesion of fluoride varnish to dentin, its cariostatic effect and low cost, it seems to be a suitable alternative to the commonly used endodontic sealers.

Endodontic management of mandibular anterior teeth with two root canals

Teeth with single root canals are considered to be the simplest for endodontic treatment. In the literature, the internal and external root canal anatomy of mandibular incisors and canines could present with a number of variations including extra canals. This case report illustrates the detection and successful nonsurgical endodontic retreatment of root canal systems in all mandibular incisors and canines in one patient.

Postoperative pain intensity associated with the use of different nickel-titanium shaping systems during single-appointment endodontic retreatment: a randomized clinical trial.

The objective of this randomized clinical trial was to compare the effect of different NiTi shaping systems on postoperative pain after single-appointment nonsurgical endodontic retreatment. Between September 2016 and December 2016, 99 patients with asymptomatic root canal-treated teeth requiring nonsurgical endodontic retreatment were randomly divided into three groups (n = 33 per group). After removing previous root canal filling, instrumentation was performed using One Shape, Revo-S, and WaveOne systems in groups 1, 2, and 3, respectively. Postoperative pain intensity was assessed at 6, 12, 18, 24, 48, and 72 hours, 7 days, and 1 month after the retreatment. Data were analyzed using one-way ANOVA and Mann-Whitney U and Kruskal-Wallis tests (alpha = .01). Up to 72 hours, postoperative pain was significantly less in group 1 than in groups 2 and 3 (P < .01). From 72 hours to 7 days, postoperative pain was significantly less in groups 1 and 2 (P > .05), compared to group 3 (P < .01). At 1 month, postoperative pain was not significantly different among all three groups (P > .05). Postoperative pain was the highest with WaveOne group. Since One Shape and Revo-S are both based on the rotational approach and WaveOne on reciprocal approach, less incidence of postoperative pain intensity with One Shape and Revo-S in single-appointment nonsurgical endodontic retreatment could be associated with the motion type during root canal shaping.

A combined management of a rare case of a maxillary lateral incisor with accessory root and deep mesio-radicular groove

This case report describes the combined nonsurgical endodontic retreatment and surgical intervention of a failed root canal treatment associated with a maxillary lateral incisor with an accessory root and deep mesio-radicular groove. A 42-year-old female Malay patient presented with persistent infection associated with deep mesial pocket from her maxillary left lateral incisor (#22). The medical history was noncontributory and the tooth was previously root treated. Following comprehensive clinical and radiographic examination, a combined nonsurgical endodontic retreatment and surgical management of tooth #22 were carried out. The inability to debride the periodontal defect necessitates the amputation of the accessory root, and surgical debridement of the deep radicular groove was carried out. The clinical and radiographic examination 1 year after completion of treatment revealed evidence of healing. The early recognition of root and canal variation, correct diagnosis, and appropriate management of tooth with accessory root and deep radicular groove is essential to ensure favorable treatment outcome.

Comparison between Single-file Rotary Systems: Part 1—Efficiency, Effectiveness, and Adverse Effects in Endodontic Retreatment

IntroductionThe aim of this study was to evaluate in vitro the performance of 3 single-file systems: WaveOne Gold Primary (WOG; Dentsply Sirona, Ballaigues, Switzerland), Hyflex EDM “one file” (EDM; Coltene/Whaledent, Alstatten, Switzerland), and XP Shaper (XP; FKG, La Chaux de Fonds, Switzerland), for nonsurgical endodontic retreatment on mandibular anterior teeth in regard to the amount of remaining filling material inside the canal, debris extrusion, and operation time. MethodsSixty extracted standardized mandibular incisors presenting with a single oval canal were prepared to size 30.04 and obturated using warm vertical condensation. After 30 days (37°C, 100% humidity), teeth were randomly divided into 3 groups (n = 20) according to the file used for retreatment (WOG, EDM, or XP operated at 3000 rpm). During the retreatment procedures, preweighed vials were used to collect apically extruded debris, and the time required to remove the filling material was recorded in seconds. Cone-beam computed tomographic scans were taken before and after the retreatment to determine the amount of remaining filling material inside the root canal space. Statistical analysis was performed using the Kruskal-Wallis test, 1-way analysis of variance, and the Pearson test at a 5% significance level. ResultsThere was a statistically significant difference among the groups regarding the instrumentation time (P < .05). XP was the fastest to remove gutta-percha from the canals (40.54 ± 28.03 seconds) followed by EDM (55.77 ± 19.76 seconds) and WOG (105.92 ± 53.92 seconds). The percentage of remaining filling was significantly greater for WOG (26.65% ± 14.63%) (P < .05). No difference was found between EDM (13.51% ± 9.53%) and XP (8.60% ± 7.28%). No difference was found regarding the amount of extruded debris among the 3 groups (P > .05). ConclusionsXP was the most efficient in gutta-percha removal from the canals when operated at a higher speed (3000 rpm) followed by EDM and WOG.

Tooth Survival after Surgical or Nonsurgical Endodontic Retreatment: Long-term Follow-up of a Randomized Clinical Trial

IntroductionThe aim of the study was to determine long-term tooth survival after endodontic retreatment and whether the presence of intraradicular posts influences the outcome. MethodsNinety-five teeth were randomly assigned to surgical or nonsurgical endodontic retreatment. Forty-seven teeth in 45 patients were treated by conventional endodontic surgery and 48 teeth (47 patients) by nonsurgical retreatment, including the removal of intraradicular posts in 37 (77%). The outcome was tooth survival; follow-up continued until the tooth had been extracted, at least 10 years had elapsed since retreatment, the patient declined further follow-up, or the patient died. The Fisher exact test was used to analyze differences between the groups. ResultsThe median follow-up time was 10.1 years (range, 0.0–15.6 years). The overall survival rate was 76%, with no significant differences in long-term tooth survival between retreatment methods or the presence of an intraradicular post. The reasons for tooth extraction were related to the retreatment method. Vertical root fractures were significantly more frequent in the nonsurgical group when retreatment included post removal (P = .036). ConclusionsThere was no significant difference in long-term tooth survival after surgical or nonsurgical retreatment. The presence of intraradicular posts did not affect long-term tooth survival, but for teeth with posts, those retreated nonsurgically were more frequently extracted because of vertical root fractures than those retreated surgically (P = .036). The major limitations of the study were a smaller sample size and the use of outmoded retreatment techniques.

Postoperative Pain Intensity after Single- versus Two-visit Nonsurgical Endodontic Retreatment: A Randomized Clinical Trial

IntroductionThe aim of this study was to evaluate postoperative pain after single-visit and 2-visit non-surgical endodontic retreatments with 2 different intracanal medicaments. MethodsA total of 150 patients with asymptomatic root canal–treated teeth in need of nonsurgical endodontic retreatment were randomly divided into 3 groups (n = 50). Patients were selected randomly from among those without preoperative pain. Patients in group 1 (single visit) were treated in a single visit. Patients in group 2 and group 3 were treated in different visits with calcium hydroxide and chlorhexidine (CHX) as intracanal medicaments. The presence of postoperative pain was assessed 1, 2, 3, and 7 days and 1 month after treatment. All 2-visit treatments were completed 1 week after the initial visit. Data were analyzed using the Mann-Whitney U, Kruskal-Wallis, and Pearson chi-square tests (α = 0.01, 0.05). ResultsPostoperative pain was significantly higher in the CHX group in comparison with the single-visit group (P ≤ .05) on the first day of assessment. On the second day, postoperative pain was significantly less in the single-visit group (P < .05) than in the other 2 groups. There were no significant differences among the groups on the third and seventh days of assessment. At the 1-month assessment, postoperative pain was significantly higher in both the calcium hydroxide group (P < .05) and the CHX group (P < .05) in comparison with the single-visit group. ConclusionsSingle-visit nonsurgical endodontic retreatment presented fewer incidences of postoperative pain in comparison with 2-visit nonsurgical endodontic retreatment based on assessments ranging from 1 day to 1 month.

Nonsurgical endodontic retreatment of a two-rooted maxillary lateral incisor

Maxillary incisor teeth have been known to have single root with a single root canal widely. The reports of anatomical variations regarding the root number of maxillary anterior teeth are limited. This case report describes the nonsurgical endodontic retreatment of a rare case of two-rooted maxillary lateral incisor tooth, emphasizing the importance of three-dimensional imaging techniques for the diagnosis of anatomical variations. A 32-year-old patient was referred for the endodontic evaluation of his tooth #22 because of failed root canal treatment. Cone-beam computed tomography revealed a palatally located extra root. Nonsurgical endodontic retreatment was performed. At the 4th month follow-up, the tooth was asymptomatic and functional.