Iranian Endodontic Journal

Introduction: This in vitro study assessed the effects of bonding application time (immediate vs. 24-hour delay) and strategy [self-etch (SE) vs. etch-and-rinse (ER)] on cytotoxicity of three calcium silicate-based cements [calcium-enriched mixture (CEM) cement, ProRoot mineral trioxide aggregate (MTA) and Biodentine] at 1mm and 2mm thicknesses. Materials and methods: Specimens (n=20 per group) were fabricated using CEM, MTA, and Biodentine. Scotchbond Universal was applied immediately or after 24 hours via SE or ER strategies. Cytotoxicity of cement extracts (100%, 50%, and 25% concentrations) on human gingival fibroblasts was evaluated using methyl thiazolyl tetrazolium (MTT) assay. Data were analyzed with four-way ANOVA and Tukey’s test (P≤0.05). Results: The biomaterials showed comparable cytotoxicity (P>0.05), with toxicity decreasing progressively at lower concentrations (25% <50%<100%). At 100% concentration, ER bonding significantly improved cell viability for CEM (P<0.05), while immediate bonding of 1-mm specimens increased cytotoxicity (P<0.05). Immediate SE bonding of 1-mm MTA and Biodentine specimens also resulted in higher cytotoxicity (P<0.05). At 50% concentration, SE strategy and 1-mm thickness increased cytotoxicity, with bonding time effects significant only in ER mode. No significant differences were observed at 25% concentration (P>0.05). Conclusion: Delayed bonding (24 hours), ER strategy, and ≥2-mm thickness minimize cytotoxicity of calcium silicate-based cements. Clinically, immediate permanent restoration after vital pulp therapy is viable when considering these parameters, eliminating the need for interim protective layers (e.g., glass ionomer bases).

Dens invagination (DI) is a developmental dental anomaly characterized by the infolding of the enamel organ into the dental papilla. Type IIIb DI, involving deep invagination that extends apically along the root, poses significant challenges in endodontic treatment due to its complex anatomy. We describe a case of type IIIb DI in a 13-year-old female referred with the chief complaint of spontaneous pain on the left maxillary lateral incisor. Clinical examinations showed tenderness to percussion and palpation as well as a positive response to cold test with lingering pain. Cone-beam computed tomography (CBCT) confirmed the presence of type IIIb DI associated with a periapical lesion. The final diagnosis was irreversible pulpitis with apical periodontitis for main canal (distal) and pulpless and infected root canal system with secondary acute apical periodontitis according to Abbott classification for the other canal. Two separate access cavities were prepared with the guidance of CBCT. Root canal therapy was performed on both root canals, using photodynamic therapy (PDT) and ultrasonic-activated sodium hypochlorite for enhanced disinfection. Calcium-enriched mixture cement was used to obturate the apical third, followed by thermoplastic gutta-percha in the middle and coronal thirds. The patient was asymptomatic at 6- and 12-month follow-ups, with radiographic evidence of complete healing. This case highlights the effectiveness of conservative endodontic treatment using PTD in managing complex DI cases, with a focus on maintaining tooth structure and achieving long-term success.

Internal inflammatory root resorption (IRR) poses significant challenges in endodontic treatment due to its potential to compromise tooth integrity. This case report describes the conservative management of IRR in a 40-year-old woman with a radiolucent lesion in the midroot of a maxillary central incisor. Early diagnosis using cone-beam computed tomography prevented perforation and guided treatment planning. Non-surgical endodontic treatment was performed using a dental operating microscope, ultrasonic irrigation, and a hybrid obturation technique. The apical portion of the canal was sealed with a bioceramic sealer and single-cone gutta-percha, while the resorptive defect was filled with calcium-enriched mixture cement due to its biocompatibility and sealing properties. At one-year follow-up, the patient was asymptomatic, with radiographic evidence of healing. This case highlights the efficacy of combining advanced diagnostic tools, bioactive materials, and minimally invasive techniques for successful IRR management.

Dentin Dysplasia Type II (DD-II) is a rare genetic disorder that affects the coronal dentin, often leading to pulp stones and complicated endodontic treatment. This case report presents the endodontic management of DD-II in an 11-year-old female patient. The patient, referred for root canal treatment, exhibited symptoms of moderate pain and was diagnosed with pulp necrosis in tooth #19; radiographic findings revealed multiple pulp stones, pulp canal calcification, and apical radiolucency. Endodontic treatment was performed, involving the removal of pulp stones with ultrasonic tips, careful cleaning and shaping of the root canals, and obturation using gutta-percha and AH-26 sealer. Twelve months post-treatment, the patient showed complete healing of the apical lesion, with no related complications. This case underscores the importance of early diagnosis and timely endodontic intervention for favorable outcomes in patients with DD-II.

Introduction: This study aimed to assess the thermal behavior of five different commercial gutta-percha brands using optical thermography. We focused on temperature differences and heat transfer characteristics at different apical distances. Materials and Methods: Gutta-percha cones from the following brands were tested: Autofit Greater Taper, Protaper Gold F2, TruNatomy Prime, ZARC Gutta-percha points # 25/0.06, and Reciproc Blue R25. A specific heating system was used to subject the cones to thermal imaging. Measurements were taken at 1-, 2-, 3-, and 4-mm apical distances for 5 mm and 10 mm cone lengths. Statistical analyses included Student’s t-tests and Analysis of Variance with the significance level set at 0.05. Results: Upon intragroup comparison, we found subtle distinctions in thermal behavior when examining gutta-percha cone lengths (5 mm versus 10 mm). TruNatomy exhibited statistically significant variations (P<0.05) at 2- and 3-mm distances. Conversely, ZARC and Reciproc Blue R25 displayed notable differences (P<0.05) at 2-, 3-, and 4-mm distances. In contrast, Autofit Greater Taper and Protaper Gold F2 consistently diverged across all distances (P<0.05). In intergroup comparisons of 5 mm length, significant variances (P<0.05) emerged among brands at 1- and 2-mm distances. At 10 mm length, TruNatomy differed significantly (P<0.05) from other brands across all distances. The heat tip maintained an average maximum temperature of 154.54^°C. Conclusion: Thermal behavior of gutta-percha brands varied significantly, with implications for endodontic treatments. While differences were observed in heat transfer and maximum temperatures, all brands remained within safe temperature ranges for clinical use. Understanding these variations can aid clinicians in selecting appropriate gutta-percha for specific clinical scenarios, ultimately optimizing root canal obturation quality.

Bio-obturation is an innovative approach in root canal therapy that effectively addresses complex clinical challenges using bioactive endodontic materials. This report highlights 14 diverse cases where bio-obturation was employed to manage complications such as internal and external resorption, root perforations, draining sinus tracts, mechanical obstructions, and trauma-related injuries. The outcomes demonstrate notable healing and resolution of various tooth related pathologies in failed primary root canal treatments. Root perforations and canal blockages were successfully sealed, restoring the integrity of the root canal system and ensuring continued tooth function and retention. Bio-obturation facilitated stabilization and regeneration of periradicular and supporting tissues in trauma cases, including avulsed teeth and inflammatory root resorption. Cases involving open apices, dens invaginatus, and complex root canal anatomy also showed favorable results. Overall, bio-obturation offers a transformative alternative to conventional root canal filling by promoting enhanced biological sealing and improved periradicular healing, thus increasing the probability of sustainable long-term clinical success. While calcium-enriched mixture cement served as the bioactive material in these cases, this approach may also be effectively implemented using other advanced calcium silicate-based biomaterials, broadening its applicability in challenging endodontic scenarios.

Taurodontism is a dental anomaly characterized by an enlarged pulp chamber and apically displaced pulpal floor. This disorder poses significant challenges in endodontic treatment, especially when perforations occur. The present case study details the endodontic retreatment of a hypertaurodont maxillary second molar in a 36-year-old female patient with a mesial canal perforation. The procedure employed a dental operating microscope for enhanced visualization and precision. Canals were prepared using a crown-down technique, with the perforation site managed using MTA and bioceramic material applied via the second mesiobuccal canal. The remaining canals were obturated using gutta-percha and bioceramic sealer. At the 1-year follow-up, the tooth was functional and asymptomatic, with radiographic evidence of a normal periodontal ligament space. This case demonstrates the efficacy of contemporary endodontic techniques, including bioceramic materials and advanced magnification, in managing the unique challenges posed by taurodontism.

Restoring endodontically treated teeth (ETT) that exhibit cracks, enlarged roots, or weakened root walls is a frequent challenge in dental practice. The present study describes three cases in which contemporary restorative techniques were employed and suggests that applying Ribbond tape (RT) to ETT can improve fracture resistance and better prevent the propagation of cracks compared with traditional methods. Although extensive in vitro research has been conducted on fiber-reinforced composites, studies evaluating the clinical use and durability of fiber-reinforced composites to restore ETT are limited. This report strictly adhered to the case report (CARE) guidelines, and the treatments were initiated only after signed informed consents were obtained from the patients. Therefore, the old restorations were removed from the teeth that required intervention and composite resin core build-up was created, followed by endodontic treatments or retreatment. Subsequently, the endodontic accesses were reinforced with RT. The protective restorations were performed and bonded. The two-year follow-ups showed that the patients had complete remission of signs and symptoms, and they remain under monitoring. The study emphasizes the importance of internal reinforcement of ETT and strengthening weakened walls with a resin core build-up reinforced with fibers like RT. This approach enhances mechanical retention, inhibit fracture propagation, and establish a strong chemical bond between RT and resin. It is suggested to be a promising strategy for increasing the longevity and strength of the teeth, providing a conservative and effective alternative to traditional methods.

Taurodontism is a dental anomaly characterized by the absence of cervical constriction at the cemento-enamel junction, apical shifting of the pulpal floor, and an expanded pulp chamber. This condition presents unique challenges in endodontic diagnosis and treatment due to its variable morphology, deeply located orifices, and complex root canal system. This paper reports three cases of hypertaurodontism (Taurodont Index ≈ 50), including a maxillary first molar, mandibular third molar, and mandibular second premolar in systemically healthy patients. The identification and treatment planning were facilitated by cone-beam computed tomography (CBCT). Root canal therapy was performed under a dental operating microscope, with careful exploration, chemomechanical instrumentation using rotary files, copious irrigation with 5.25% sodium hypochlorite, and warm vertical obturation. Twelve months later, follow-up visits showed that all patients were clinically and radiographically asymptomatic, indicating successful outcomes. Taurodontism presents significant challenges due to its anatomical complexities. A multifaceted approach involving CBCT, dental operating microscopes, ultrasonic irrigation, and warm vertical obturation is recommended. This case series demonstrates that with advanced diagnostic aids and meticulous techniques, even hypertaurodontic teeth can be effectively managed.

Regenerative endodontic procedures (REPs) have emerged as a biologically driven approach for managing immature teeth with necrotic pulp and open apices, providing an alternative to traditional apexification techniques. This case report describes the successful treatment of a three-rooted immature mandibular first molar with necrotic pulp and chronic apical periodontitis in a 9-year-old patient using REPs. The treatment followed the guidelines set by the American Association of Endodontists and utilized a two-visit protocol. Concentrated growth factor (CGF) was employed as a biological scaffold in the root canals, while calcium-enriched mixture (CEM) cement was used for the coronal seal. Radiographic evaluations conducted at 6, 12, and 15 months revealed progressive periapical healing, significant root elongation, increased thickness of the root walls, and partial apical closure. Clinically, the patient remained asymptomatic during all follow-ups. This case highlights the potential of CGF and CEM cement-enhanced REPs to promote continued root development and achieve predictable outcomes in immature teeth with necrotic pulps, offering a biologically based alternative to conventional apexification.

In the article titled Revascularization of a Previously Treated Mandibular First Molar with Open Apices: A Case Report by Mojgan Feli, Anita Taheri and Mahgol Mehrabani, published in the Iranian Endodontic Journal [2024;19(2):120-123; doi: 10.22037/iej.v19i2.43321], the authors regret an omission in the acknowledgment section of the original publication.

Dens invaginatus is a developmental anomaly resulting from the infolding of enamel and dentin into the dental pulp. Oehlers’ Type IIIa dens invaginatus poses significant challenges due to its intricate anatomy and frequent association with immature teeth. This case report outlines the nonsurgical management of a nonvital immature maxillary central incisor with Type IIIa dens invaginatus, presenting with a chronic apical abscess and a history of trauma to the associated primary incisor. Treatment involved thorough chemomechanical debridement followed by bio-obturation using calcium-enriched mixture cement. Regular follow-ups revealed complete resolution of the periapical lesion. This case underscores the importance of precise diagnosis, individualized treatment planning, and the application of advanced biomaterials in addressing complex presentations of dens invaginatus. The successful outcome emphasizes the efficacy of nonsurgical techniques in preserving immature teeth while restoring function and aesthetics.

An acute apical abscess (AAA) is a rapid-onset inflammatory condition characterized by spontaneous pain, pus formation, and swelling, often resulting from pulp necrosis. Complications may include systemic manifestations and severe outcomes, such as tooth extrusion. This case report describes a rare instance of AAA causing rapid extrusion of a maxillary central incisor in a 17-year-old female. The patient presented with spontaneous pain and mobility of the extruded tooth, accompanied by localized swelling. Clinical and radiographic evaluations revealed pulp necrosis, an AAA, and apical bone rarefaction. Emergency treatment was initiated, including intracanal medication with calcium hydroxide and temporary splinting of the tooth. Subsequent treatment involved obturation with gutta-percha and sealer, followed by permanent restoration. Radiographic and clinical recalls up to 5 years demonstrated complete periapical healing, normal tooth mobility, and no recurrence of symptoms. Effective management, including timely root canal therapy and splinting, led to successful long-term outcomes. This case underscores the importance of prompt diagnosis and immediate, tailored treatment to manage AAA and prevent severe complications.

Dens invaginatus is a developmental malformation that is caused by the invagination of the enamel organ into the internal region of the dental papilla before tissue calcification. The aim of the present report is to discuss a clinical case of endodontic treatment of tooth #12, using bioceramic sealer. The extraoral examination revealed atypical anatomy, while vitality and percussion tests were negative, palpation test was positive. Edema was observed in the adjacent gingival mucosa. Based on clinical and tomographic findings, the diagnosis was pulp necrosis with chronic periapical abscess and Oehlers’ type II dens invaginatus. In the first session, access surgery was performed with spherical drills with the aid of an operating microscope (OM) and an ultrasonic diamond tip. Four canals were located, and they were partially debrided and medicated. In the second session, odontometry and chemical-mechanical preparation with nickel-titanium instruments were performed. The irrigation solution was 2.5% sodium hypochlorite. The root canals were filled with calcium hydroxide paste and the chamber was temporarily sealed. During the third session, ultrasonic irrigation was applied for final washing and the root canals were filled with Bio-C sealer using the classic single-cone technique. At 6-month follow-up, the tooth was asymptomatic and the radiography revealed significant bone repair. It was concluded that tomography, operating microscope, ultrasonic irrigation, and materials with greater flow, such as bioceramic sealers, enhanced the clinical success of the clinical case.

Permanent maxillary second molars’ root canal treatment due to their root configurations complexity and high root canal systems variations, are one of the most problematic teeth. Accordingly, clinicians should consider unusual canal morphology to reduce the rate of missed canals.  A thirty-year-old female was referred for root canal treatment of her maxillary right second molar tooth with obvious recurrent caries under restoration and necrotic pulp. Pre-operative radiographs showed the unusual morphology and cone-beam computed tomography was ordered for precise evaluation of the root canal anatomy. The principal aim of this paper is to report a five-root canals maxillary second molar, with two palatal root canals and a palatal root-like enamel pearl canal.

Paresthesia is described as a burning or prickling sensation or partial numbness caused by neurologic injury. The sensory loss may be the result of a reversible and/or irreversible nerve damage, and it can be caused by local or systemic factors. Local factors include traumatic injuries caused by impacted teeth, local injection, endodontic therapy, implant placement and exposure to toxic materials. This article reports a paresthesia by anesthetic injection. A 44-year-old man reported moderate pain during chewing and exposure to cold. Upon clinical examination, extension of the tooth fracture line was in the mesiodistal region of the mandibular left second premolar crown and was detected with 16× magnification of microscope. The diagnosis was cracked tooth syndrome, and root canal treatment was indicated. After the first appointment the patient reported altered sensation on left side of mandible, numbness and electric shock sensation, and therefore was diagnosed with mental nerve paresthesia. Diclofenac sodium, thiamine, cyanocobalamin, and pyridoxine were prescribed for 7 days as part of the treatment, and then root canal and restorative treatments were completed. Patient was scheduled for follow-up appointments after 1, 3, 6, and 8 months. After the first month, the feeling of paresthesia was still present and the patient was experiencing a painful “electric shock”. At the 8-month follow-up visit, the paresthesia had been resolved with return of normal sensation.

Introduction: The middle mesial canal (MMC) of mandibular molars is of particular interest in endodontics due to its complexity. This study investigated the association between MMC presence in first and second mandibular molars and the radiolucency in the furcation area using cone-beam computed tomography (CBCT) scans. Materials and Methods: CBCT scans of 400 patients referred to the largest radiology center in Kerman City from January 1, 2022, to January 1, 2023, were examined. All CBCT scans were assessed for radiolucency in the furcation area and the presence of MMC. Variables, including age, gender, tooth number, and MMC presence were recorded. Chi-squared tests and logistic regression analyses were employed to compare MMC frequency and its impact on furcation radiolucency. Results: Of 201 examined teeth, 37 (18.4%) had MMC, and 23 (11.4%) exhibited furcation radiolucency. However, teeth with a mesial canal showed a higher prevalence of furcation lesions compared to those without (38% vs. 5.2%) (P<0.001). A significant association was observed between a mesial canal and furcation radiolucency, with odds of furcation radiolucency at 12.7 after controlling for age and gender (P<0.001). Conclusion: A strong association exists between MMC presence in first and second mandibular molars and furcation radiolucency, unaffected by age and gender.

Introduction: This systematic review compared the accuracy of guided endodontics with the conventional method in non-surgical endodontic retreatment. Methods: Two reviewers conducted a systematic search across PubMed/MEDLINE, Scopus, Embase, and Web of Science databases. Inclusion criteria consisted of all in vitro studies up to October 2024 that documented the application of cone-beam computed tomography in creating a guide for endodontic retreatment cases. The reviewers assessed the quality of the selected studies using the QUIN tool. Data regarding the first author and publication year, sample size, tooth type, retreatment application, computer-aided navigation technique, groups, image acquisition method, outcome measures, guided technique results, conventional technique results, and the main results were extracted using a predefined template. Results: Based on our criteria, seven studies were included in this review. The studies demonstrated variability in the techniques utilized. Iatrogenic errors were less frequent in guided groups, regardless of the operator’s level of experience. Most studies indicated that guided endodontics was more effective than conventional methods, particularly in fiber post-removal and access through MTA, minimizing volumetric loss of tooth structure, and preserving fracture resistance. However, when using guided techniques for removal of separated instruments, more iatrogenic errors occurred, and more time was required compared to the freehand technique. Conclusion: Guided endodontics has shown promise in improving the outcomes of non-surgical retreatment by reducing complications. However, as all included studies were in vitro, clinical evidence is lacking, and the generalization of these results should be done cautiously. Further well-designed clinical studies are required to confirm these findings.

Vital pulp therapy (VPT) comprises a range of conservative treatment modalities aimed at preserving the vitality of the compromised dental pulp in primary and permanent teeth. This PubMed-based review comprehensively evaluates seven distinct VPT techniques; including their historical development, broad definitions, clinical protocols and treatment outcomes as evidenced by systematic reviews and meta-analyses. The VPT modalities covered in this review include stepwise excavation, indirect pulp capping, direct pulp capping, miniature pulpotomy, partial pulpotomy, full pulpotomy and partial pulpectomy. Stepwise excavation, as a minimally-invasive option, has demonstrated effectiveness in reducing the risk of pulp exposure, particularly in permanent teeth. Clinical outcomes of indirect and direct pulp capping are promising; specifically with the application of advanced calcium silicate cements. Miniature and partial pulpotomies emphasize the importance of precise definitions and standardised protocols due to their subtle differences. Full pulpotomy has emerged as a viable alternative to root canal treatment, achieving comparable success rates in managing irreversible pulpitis. While partial pulpectomy remains the most invasive approach, it has shown potential in managing complex cases, such as root resorption, through selective tissue preservation. Despite advancements in biomaterials and technique standardisation, challenges remain, including variability in clinical protocols, limited high-quality evidence, and the need for long-term studies to better evaluate anticipated outcomes. Nevertheless, emerging biotechnologies hold promise for enhancing the precision and predictability of VPT procedures in the future.