Iranian Endodontic Journal

Introduction: One of the most common problems in endodontic treatments is post-treatment pain, and sealers might be one of the factors influencing the degree of pain following root canal therapy. The purpose of this study is to compare pain following endodontic treatment using an AH-26 resin sealer against the Resil experimental sealer in mandibular molars with irreversible pulpitis. Materials and Methods: One hundred patients with irreversible pulpitis in the mandibular first or second molar were randomly divided into two groups (n=50) based on the type of sealer applied. Two postgraduate students with at least five years of experience treated all patients. All patients had a single root canal treatment. Postoperative pain scores and analgesic consumption were assessed after 6, 12, 24, and 48 hours and 3, 4, 5, 6, and 7 days after the treatment. The data were statistically analyzed by Fisher's exact or Chi-Square test (to compare the distribution of qualitative variables in two groups), repeated measures ANOVA (to compare changes in pain intensity over time in two groups), Boneferronie (for pairwise comparisons), Friedman, Wilcoxon and Mann-Whitney tests (for assessment of the changes in pain scores over time). The generalized estimating equations (GEE) were used for assessing time and group effects. Results: There was no significant difference in postoperative pain between groups at any of the time points studied (P>0.05), and also for patient analgesic consumption between groups (P>0.05). Both groups recorded the maximum pain levels in the first 6 hours. For each subsequent day postoperatively, the odds ratio (OR) of not using analgesics was 2.078. Conclusion: Resil and AH-26 perform similarly in terms of the occurrence and intensity of postoperative pain in mandibular molar teeth with irreversible pulpitis.

Apical periodontitis (AP) is a common inflammatory condition predominantly caused by the response of the immune system to microbial invasion within the root canal system. Contrary to conventional perception, AP may occur in vital teeth with inflamed pulp; adding complexity to diagnosis and treatment. AP, due to its frequent lack of symptoms and reliance on radiographic evaluation for detection, often presents diagnostic challenges. In addition, AP pathogenesis involves complex interactions between microbial virulence and host immune response at the cellular and molecular levels. Comprehensive diagnostic procedures, including patient history, clinical examination, and radiographic evaluation, are essential for early detection and necessary intervention, with the recognition of clinical signs and symptoms underscoring the importance of regular dental evaluations. The current review primarily discusses the radiographic and clinical features of AP in vital and non-vital teeth; introducing a new taxonomic classification to improve diagnostic precision and treatment outcomes. Moreover, it proposes different treatment categories/options for the management of AP, based on pulp status as well as clinical and radiographic findings; emphasizing vital pulp therapy and root canal treatment for vital and non-vital teeth with AP, respectively. Furthermore, the global and regional epidemiology of AP is presented, along with its association with systemic health conditions; e.g., cardiovascular diseases, diabetes mellitus, and adverse pregnancy outcomes. Moreover, future research directions are advocated to improve the efficacy and predictability of diagnosis and treatments; paving the path for clinicians in early detection, accurate diagnosis, and effective management of AP to enhance oral health outcomes.

Currently no standard, universally accepted, and clinically useful classification of pulp, root canal and peri-radicular conditions is used within the dental profession. Most published classifications are either too simple and miss many of the conditions reported to occur within the pulp, root canal and peri-radicular tissues, or they are too complex for use in clinical settings. Furthermore, many classifications have used inappropriate terminology that has either not been defined or has been poorly defined. The lack of standardisation leads to confusion amongst practitioners and potential uncertainty regarding treatment. It also limits the ability to communicate effectively, to teach appropriately, and to compare data and research findings throughout the world. When developing a classification of tissue conditions or diseases, it is essential that the classification is developed appropriately and meets the recommended criteria for effective clinical, educational and research use. It is also extremely important that correct and well-defined terminology is used since “words do matter”. Popular terminology based on symptoms should be avoided as these have been proven to lead to inappropriate treatment decisions. This review discusses how classifications should be developed for pulp, root canal and peri-radicular conditions. It also discusses the deficiencies of some popular classifications and outlines the classifications that truly address the recommended criteria and reflect the physiological and pathological changes in the pulp, root canal and peri-radicular tissues. Hence, it is recommended that these latter classifications be adopted as the internationally-accepted classifications for future clinical use, as well as for educational, research and communication purposes.

Introduction This study used different irrigation techniques to compare the levels of apical bacterial extrusion during the preparation of root canals with a reciprocating instrument widely used in endodontics, the Reciproc files 25/0.08 and 40/0.06. Materials and Methods: The irrigation techniques employed were conventional syringe irrigation and passive ultrasonic irrigation (PUI); the latter, with one or two activation cycles. Seventy extracted mandibular human premolars were contaminated with Enterococcus faecalis for 5 days and were distributed into 6 experimental groups (n=10), and the remaining specimens were used as positive and negative control groups (n=5). Group 1: instrumentation performed with Reciproc 25/0.08 and conventional syringe irrigation; Group 2: instrumentation performed with Reciproc 25/0.08 along with PUI for one minute after instrumentation (PUI-1); and Group 3: instrumentation performed with Reciproc 25/0.08 along with PUI for one minute before and after instrumentation (PUI-2). Groups 4, 5 and 6 were instrumented with Reciproc 40/0.06, and irrigation was performed similar to the previous groups, in the aforementioned order. Each root canal was irrigated with saline solution. Extruded debris was collected in microtubes. The contents of the microtubes were homogenized, diluted, and spread on Brain Heart Infusion agar. After 48 hours, the number of colony-forming units was determined for each sample. For statistical analysis, the Kruskal-Wallis test followed by the Dunn’s tests were used (α=0.05). Results: The CFU/mL count indicated that the instrumentation with Reciproc 25/0.08 was associated with the highest bacterial extrusion, mainly when PUI was performed (P<0.05). Conclusion: All the instrumentation techniques caused bacterial extrusion through the apical foramen; however, the largest file size of the Reciproc 40/0.06 groups was associated with less apical bacterial extrusion.

Introduction: Successful endodontic treatment depends on completely clearing, shaping, and filling the prepared canals. Knowledge of the common and aberrant varying pulp anatomies is essential for suitable root canal treatment. Since, this anatomy is complex and varies morphologically in different populations. This study aims to determine the number of roots, canals, and evaluation of mandibular premolars canals using cone-beam computed tomography (CBCT) images in one of Iran's northern provinces (Golestan). Materials and Methods: CBCT axial, coronal, and sagittal slices of two hundred and twelve mandibular premolars were analyzed to determine the number of roots and canals based on Vertucci type. The images were analyzed in a one-millimeter slice in mesiodistal and buccolingual dimensions based on gender. The data were analyzed using the Chi-score test to compare the components if the defaults were not established. A significance level of 0.05 was considered. Result: Of the two hundred twelve teeth evaluated, 130 (61.3%) were first premolars, and 82 (38.6%) were second premolars. Most first premolars (78.5%) and almost all second premolars (97.6%) had one root. Morphological types of root canals were identified based on Vertucci’s classification types I, II, III, IV, V, or VIII, and type I was the most frequent. There were no significant associations between number of roots and sex (P>0.05). Conclusion: Mandibular premolars mostly had one root and type I Vertucci morphology. The frequency of two-canal premolars was higher in the male population. Although the abundance of two or three roots with different morphologies was also observed, the possibility of the presence of an additional root canal should be considered.

Introduction: Ultrasonic vibration for metallic post removal seems to be a unanimous choice between endodontists and general practitioners for providing the best results and having the highest safety. This study compared the time required by ultrasonic vibration for removing metallic post (MP) when 1 or 2 ultrasonics devices are used. Materials and Methods: One hundred and fifteen teeth with MPs from 105 patients, indicated for nonsurgical endodontic retreatment were divided into 2 groups according to the number of ultrasonic devices used (G1-1 device) and (G2-2 devices). In G1, the MP was worn with a transmetal bur, alongside the wear of the cement line (around 2 mm deep). Then, an ultrasonic tip attached to an ultrasonic unit, with a power of 100% was activated at the level of the post, with constant water spray at a level of 1 mm above the axial surface of the tooth. The position of the tip was changed between buccal and lingual surfaces every 10 seconds until the MP was removed. In G2 the same procedures were performed as described in G1, but two ultrasonic tips were activated simultaneously at buccal and lingual surfaces until the MP was removed. The vibration time necessary for removing each MP was recorded using a chronometer. Results: The mean time was 131.10±29.68 seconds (mean±standard error of the mean) for MP removal using one ultrasonic device, and 24.86±6.88 seconds for two devices. The time required for MP removal using two ultrasonic devices was significantly less than when using one ultrasonic device (P<0.001). Conclusion: The technique with 2 ultrasonic devices proved to be more efficient than the one using only 1 ultrasonic device.

Introduction Rotary systems have made significant advances to improve their root canal preparation efficacy. These instruments can properly preserve the root canal anatomy and morphology. The present in vitro study aimed to compare canal transportation and centering ability of RaCe and Af f-one systems using cone-beam computed tomography. Materials and Methods: Thirty-six mandibular molars were included. The samples were randomly assigned to two groups (n=18): group 1, RaCe, and group 2, Af f-one. Canal preparation was conducted using the respective files according to the manufacturers’ instructions. The cone-beam computed tomographic scanning of the samples was performed before and after preparation. The data were analyzed by using two-way ANOVA. Results: In both the RaCe and Af f-one rotary systems, canal centrality and transportation were similar at coronal, middle, and apical cross-sections. In addition, canal transportation and centrality were identical in the RaCe and Af f-one rotary files (P<0.05). Conclusion: The two studied rotary systems did not exhibit significant differences in root canal transportation and preservation of root canal centrality in the apical, middle, and coronal thirds.

Introduction This study aimed to compare the effectiveness of two endodontic cleaning techniques, passive ultrasonic irrigation (PUI) and the XP-endo Finisher R (XPR) system, in removing residual filling material during endodontic retreatment procedures. Materials and Methods: Forty mandibular premolars with oval canals were divided into four groups based on the sealer used (AH-Plus or Bio-C Sealer) and the cleaning technique employed (PUI or XPR). To ensure uniformity of canal volume among groups, initial micro-CT scans were conducted. The canals were instrumented, filled, and then re-instrumented before undergoing either PUI or XPR cleaning techniques. Residual filling material volumes were assessed through micro-CT scans, and statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests. Results: Following instrumentation, there was no significant difference in residual filling material volumes between AH-Plus and Bio-C Sealer groups (1.35 mm³and 1.02 mm³, respectively; P>0.05). However, after supplementary cleaning techniques, XPR-cleaned specimens exhibited significantly less residual material compared to PUI-cleaned specimens (0.01  mm³ and 0.29 mm³ for Bio-C Sealer, and 0.07 mm³ and. 0.30  mm³ for AH-Plus, P<0.05). Conclusion: The XPR system was found to be more effective than PUI in removing residual filling material from Bio-C Sealer-filled root canals. This highlights its potential as a useful supplementary cleaning technique in endodontic retreatment procedures.

Introduction: Untreated canals represent the primary cause of treatment failure in molars and the second leading cause in other dental groups. This study determined the prevalence of untreated canals and their relationship with periapical periodontitis using cone-beam computed tomography (CBCT) images. Materials and Methods: 385 CBCT images with at least one treated canal were selected from the oral and maxillofacial radiology center. The number of roots and canals, presence, and size of periapical pathology, and presence of untreated canals were recorded. The study used descriptive statistics and Chi-square, Fisher's exact, and odds ratio tests to analyze data. Results: Of the 2053 teeth examined, 14.9% had at least one untreated canal. Untreated canals in teeth increase the chance of having a periapical lesion, raising the prevalence by 11 times. Of these, 91.8% had both untreated canals and periapical lesions. This was more than teeth without untreated canals (35.8%). Most untreated canals were in maxillary molars (65.3%), and mandibular molars (12.54%). There was a statistically significant relationship (P<0.001) between the number of roots, canals, expansion, destruction, and jaw type with the prevalence of untreated canals. The maxillary first molar (68.66%) and second mesiobuccal (MB2) canal (63.27%) had the highest percentages of untreated canals. Conclusions: The MB2 had the highest prevalence of untreated canals. The presence of untreated canals significantly increased the risk of expansion and/or destruction. Therefore, identifying these conditions can also be useful in diagnosing untreated canals. Dentists should assess the anatomy of the tooth and the structure of the root canal to minimize the possibility of an untreated canal. CBCT can assist in this process.

Introduction: Occupational burnout has been introduced as one of the most critical social problems. The present study aimed to evaluate occupational burnout among a group of Iranian endodontists. Material and Methods: Seventy-two Iranian endodontists participated in this cross-sectional study by completing the abbreviated Maslach Burnout Inventory (aMBI), consisting of one questionnaire in three domains. The data were analyzed with SPSS 21, using the chi-squared test, correlation test, and linear regression. Results: Concerning occupational burnout, 2.9% of the participants had severe emotional exhaustion, 4.2% exhibited an intense feeling of decreased accomplishment, 67.2% exhibited moderate occupational burnout, and 78.9% of the participants were satisfied with their job. Of all the variables, only the years elapsed since graduation had an inverse and significant correlation with occupational burnout among endodontists. Conclusion: The overall mean scores of endodontists showed a moderate rate of occupational burnout compared to the standard mean scores in this field. Recent graduates exhibited higher scores.

Root canal obliteration is caused by hard tissue apposition and is often associated with teeth with a history of trauma, orthodontic movement, caries reaction, restorative procedures near the pulp chamber, and teeth of elderly patients. Preoperative planning of root canal treatment should be thorough and include an assessment of the patient's signs and symptoms in addition to the evaluation of complementary examinations. In a 27-year-old patient with dyschromia of the lower central incisor, a history of dental trauma, and a positive response to vertical percussion, an initial periapical radiograph was obtained that showed calcification of the canal and presence of a periapical lesion. The patient presented with pain on chewing, a positive response to palpation and a vertical percussion test. The diagnosis was symptomatic apical periodontitis. A cone-beam computed tomography scan was requested and a surface scan was performed to establish a static guide. The root canal was accessed in the middle third of the root and the canal was located using a minimally invasive approach. The root canal was treated conventionally. Results obtained showed the success of the treatment after a 3-year clinical and radiographic follow-up. Therefore, the use of an endodontic guide in cases of calcified canals significantly reduces the clinician's working time and offers a more predictable approach to the treatment of these pathologies.

A complete understanding of canal morphology is essential to achieve successful endodontic treatment. Although mandibular second premolars are reported to have usually only one root canal at the apex, in this case we reported a mandibular second premolar with three root canals and taurodont morphology. A patient was referred to the endodontic department at Mashhad Faculty of Dentistry with a chief complaint of pain in her mandibular right second premolar tooth. The diagnosis of pulpal necrosis and chronic apical periodontitis was established. The initial radiograph showed a taurodont premolar with two roots. However, with cone-beam computed tomography assistance, three root canals were confirmed. The root canal treatment process was successfully managed with a dental operating microscope. Using cone-beam computed tomography and a dental operating microscope greatly facilitated the determination of tooth morphology and successful following nonsurgical endodontic treatment.

Dens invaginatus (DI) is one of the developmental dental anomalies that results in an invagination of the enamel organ into the dental papila during odontogenesis. The purpose of this study is to report a case of nonsurgical endodontic treatment of an Oehlers type II DI in a right maxillary lateral incisor with an extensive periapical damage, along with the two-year clinical and tomographic follow-up. A 30-year-old patient was referred for endodontic treatment of tooth #12. On clinical examination, a change in the shape and color of the crown was observed. The tooth responded negative to pulp sensibility, percussion, palpation and mobility tests. After tomographic evaluation, an Oehlers type II DI was visualized, in addition to an extensive periradicular lesion. The diagnosis was asymptomatic apical periodontitis. The treatment was carried out in two sessions, through intense enhancement of the auxiliary chemical substance with passive ultrasonic irrigation, XP-Endo Finisher and the use of hydroxide-based intracanal medication. Appropriate treatment in cases with anatomic variations requires an accurate and early diagnosis based on clinical examination and radiographic images. A two-year follow-up of the present case showed that the correct diagnosis associated with appropriate instrumentation techniques, supplementary disinfection, and adequate three-dimensional sealing of the canal with filling material, resulted in regression of the periradicular lesion and bone repair.

Immediate care and accurate diagnosis are essential for treating dental trauma. This report presents a 7-year-old boy suffered a bicycle accident with direct trauma to the mouth and extrusive luxation of teeth #11 and #21. The emergency treatment was performed within the first hour. Clinical examinations showed that both teeth exhibited 3 mm extrusion from comparing their incisal edges to their neighboring teeth, had edematous gingiva, showed grade 3 mobility and were painful to percussion. Radiographic exams showed incomplete root formation, widened periodontal spaces along their entire lengths and absence of bone or root fractures. The treatment consisted of immediate repositioning and semi-rigid splinting. After 15 days, tooth #11 exhibited no clinical signor symptom and tooth #21 was diagnosed with pulp necrosis, with an acute dentoalveolar abscess and intraoral edema. Immediate endodontic treatment was initiated (intracanal dressing with calcium hydroxide paste). At 30 days, another pulp sensibility test was performed on tooth #11, which had a negative response. In the same visit, the intracanal dressing of tooth #21 was replaced. The Ca(OH)₂ medication was replaced every 6 months until the formation of an apical barrier. The final dressing consisted of gutta-percha and Grossman’s sealer and was placed two and a half years after the first dressing appointment. The extrusive luxation resulted in two different sequelae: complete root obliteration in tooth #11 and anomalous root development after the formation of an apical barrier in tooth #21. The patient received orthodontic treatment after 6 years from the initial treatment with no negative outcome. After 18 years follow-up, both teeth were stabilized with no symptom or sign. It’s important to follow the evolution of every trauma case continuously because the sequelae can be unpredictable.