Jorge N.R. Martins

Clinical efficacy of electronic apex locators: systematic review.

INTRODUCTION Apical constriction has been proposed as the most appropriate apical limit for the endodontic working length. Despite being the most used, some limitations are attributed to the radiographic method of working length determination. It lacks precision because it is based on the average position of the apical constriction. The electronic apex locators have been presented as an alternative to the odontometry performed by radiography. These devices detect the transition of the pulp to the periodontal tissue, which is anatomically very close to the apical constriction and may perform with improved accuracy. METHODS A systematic review was performed to compare the radiographic and electronic methods. Clinical studies that compared both methods were searched for on 7 electronic databases, a manual search was performed on the bibliography of articles collected on the electronic databases, and the authors were contacted to ask for references of more research not detected on the electronic and manual search. RESULTS Twenty-one articles were selected. The majority were comparative or evaluation studies, and very few clinical studies comparing both methods are available. Several methodological limitations are present on the collected articles and debated in this review. CONCLUSIONS Although the available scientific evidence base is short and at considerable risk of bias, it is still possible to conclude that the apical locator reduces the patient radiation exposure and also that the electronic method may perform better on the working length determination. At least one radiographic control should be performed to detect possible errors of the electronic devices.

Worldwide Prevalence of Mandibular Second Molar C-Shaped Morphologies Evaluated by Cone-Beam Computed Tomography

Introduction The aim of this study was to evaluate and compare the C‐shaped mandibular second molar prevalence in different regions around the world with the aid of cone‐beam computed tomography technology. Methods Nine field observers from 9 different geographic regions were calibrated. A total of 400 samples were collected in each region. The prevalence of C‐shaped anatomy was calculated. The number of roots and the configuration of the C‐shaped canals at 3 different axial levels were also evaluated. The z‐test was used to analyze the difference between the means of each independent group. Intrarater reliability was also tested. Results A total of 3600 teeth from 2735 patients were included in this research; 499 teeth presented C‐shaped root canal configuration, representing a global prevalence of 13.9%. China had a prevalence of 44.0%, which was significantly higher than any other region. The C‐shape prevalence in women was 16.5%, which was significantly higher than the 10.4% prevalence found in men. No difference between sides (37 or 47) was evident in the global sample. Conclusions Cone‐beam computed tomography is a valuable tool to evaluate the C‐shaped root canal configuration in vivo. In the present study, China presented the highest prevalence of C‐shaped mandibular second molars when compared with other regions. Women exhibited a higher prevalence than men.

Prevalence of C-shaped Configurations in the Mandibular First and Second Premolars: A Cone-beam Computed Tomographic In Vivo Study

Introduction The mandibular premolar C‐shaped anatomy has been presented as a complex morphology to be treated. The objective of this retrospective observational study was to evaluate and characterize, in in vivo conditions, the incidence of these morphologies using cone‐beam computed tomographic (CBCT) technology. Methods Mandibular premolar CBCT samples were collected from a preexisting database. All teeth were analyzed in 3 planes (axial, coronal, and sagittal), and the C‐shape classification was performed at 3 different axial levels (coronal, middle, and apical). C‐shape presence and configuration were recorded as well as the number of roots, the presence of a radicular groove, and Vertucci classification. The Z test for proportions was used to analyze the differences between independent groups. Intraobserver reliability was tested using the Cohen kappa test. Results Two thousand twelve mandibular premolars were included in this study. A prevalence of C‐shaped morphologies was noted in 2.3% and 0.6% of mandibular first and second premolars, respectively. This clinical condition was mostly unilateral. The C‐shaped configuration (C1 and C2) was found mainly in the middle axial level. Its presence was uncommon in the apical level and null in the coronal level; 61.5% of all mandibular first premolar C shapes were identified in Vertucci type V roots. Differences were observed among sex, teeth, and Vertucci root configuration at P < .05. Conclusions Although the mandibular premolar C‐shaped anatomy has a low prevalence ratio, a clinician should be aware of its existence, mainly when treating roots with Vertucci type V configuration. The prevalence was statistically higher in first premolars and males.

Prevalence of C-shaped mandibular molars in the Portuguese population evaluated by cone-beam computed tomography.

Objective: The purpose of this study was to evaluate the prevalence of first and second C-shaped mandibular molars in a Western European population of Portuguese Caucasians. Materials and Methods: Patients having both routine panoramic radiograph and presurgical cone-beam computed tomography (CBCT) exams were selected. The CBCT examination was performed at five different axial levels and the mandibular molars were classified as C-shape according to the Fan criteria. Differences between genders, age groups, left and right side, type of tooth, and root concavity side were determined. The molars were classified as nonfused roots (NFRI–II), FRI–III, or single root with single canal (SS) groups, using the panoramic radiograph. The prevalence of C-shaped anatomy was calculated to each group. Results: A total of 1783 teeth (695 first molars and 1088 second molars) from 792 patients were included in the study. The prevalence of C-shaped configurations was 0.6% and 8.5% to mandibular first and second molars, respectively. The differences between gender, teeth, and root concavity direction were considered statistically significant (P < 0.05). The FR had a significantly higher rate of C-shapes when compared to NFR (P < 0.05). Intrarater reliability was 93.6%. Conclusions: The FR radiographic appearance may be considered a predictor of this anatomy. Second mandibular molars and females had a higher incidence ratio. Apparently, the mandibular C-shaped anatomy is more common in the population of this study than that has been previously reported for the European population.

Prognosis of Indirect Composite Resin Cuspal Coverage on Endodontically Treated Premolars and Molars: An In Vivo Prospective Study

PURPOSE This prospective clinical study evaluated the success rate of indirect composite resin cuspal coverage on endodontically treated molars and premolars and the survival rate of the restored teeth. MATERIALS AND METHODS One hundred fifty endodontically treated teeth were restored with total resin cuspal coverage and randomly selected for the study. Patients were recalled after 2 to 5 years for clinical evaluation. Data were subjected to standard tests of statistical correlations using Spearman test. RESULTS Out of the 150 teeth, 84 were molars and 66 were premolars. Of these teeth, 58.7% had mesio-occlusal-distal (MOD) cavities, 20.7% had mesio-occlusal (MO), and 20.7% had occlusal-distal (OD). A build-up procedure was performed in 51.3% of the teeth, and buccal veneer composite resins were placed at the margins of 96.7% of the teeth. Out of the 150 teeth, 30 (20%) presented margin discoloration, 3 teeth (2%) had restoration reparable fractures, 2 teeth (1.3%) had restoration irreparable fractures, and 1 tooth (0.7%) exhibited secondary recurrent caries. The opposing arch that occluded with the treated teeth presented 58% natural teeth (no restoration material), 26.7% ceramic crowns, and 15.3% implant-supported ceramic crowns. Statistically significant differences (p = 0.018) between irreparable restoration fractures and the type of support material present in the opposing arch were found. CONCLUSIONS In a period of up to 5 years, the resin cuspal coverage of endodontic treated teeth had a success rate of 96%, while the tooth survival rate was 100%. The type of support material on the opposing arch may influence the longevity of the restoration of endodontically treated teeth.

Endodontic treatment of a maxillary first molar with seven root canals confirmed with cone beam computer tomography - case report.

The most common configuration of the maxillary first molar is the presence of three roots and four root canals, although the presence of several other configurations have already been reported. The objective of this work is to present a rare anatomic configuration with seven root canals diagnosed during an endodontic therapy. Endodontic treatment was performed using a dental operating microscope. Exploring the grooves surrounding the main canals with ultrasonic troughing was able expose unexpected root canals. Instrumentation with files of smaller sizes and tapers was performed to prevent root physical weakness. The anatomic configuration was confirmed with a Cone Beam Computer Tomography image analysis which was able to clearly show the presence of seven root canals. An electronic database search was conducted to identify all the published similar cases and the best techniques to approach them are discussed.

Differences on the Root and Root Canal Morphologies between Asian and White Ethnic Groups Analyzed by Cone-beam Computed Tomography

Introduction: Populations from different geographic regions and ethnic backgrounds may present differences in dental morphology. The aim of this study was to compare the differences in root and root canal configurations on Asian and white subpopulations using cone‐beam computed tomographic imaging. Methods: Information from Asian and white patients was retrieved from 2 cone‐beam computed tomographic imaging databases in China and Western Europe. Two calibrated observers collected data regarding the number of roots and Vertucci root canal system configuration for all groups of teeth. A total of 15,655 teeth were analyzed. The z test for independent groups was used to analyze differences between the groups. The significance level was considered at a P value < .05. Reliability tests were performed between observers. Results: Differences were noted in the number of roots per tooth in 6 groups of teeth. The Asian group showed a higher prevalence of single‐root configurations in maxillary first premolars (83.2%) and mandibular second molars (45.4%) when compared with whites with 48.7% and 14.3%, respectively. Moreover, 3‐rooted configurations in mandibular first molars were more common in Asians (25.9%) compared with whites (2.6%). Seventeen of the 20 analyzed roots had a higher prevalence of Vertucci type I configuration in Asians. Maxillary first molars with second mesiobuccal root canals were more commonly found in whites than in Asians (71.3% and 58.4%, respectively). A similar situation was found in maxillary second molars. Conclusions: The Asian ethnic group presented a higher prevalence of Vertucci type I configuration, whereas the white group displayed a higher number of multiple root canal system morphologies. A clinician should be aware of these differences when treating patients from these ethnic groups.

Very Large Inflammatory Odontogenic Cyst with Origin on a Single Long Time Traumatized Lower Incisor.

One of the consequences of traumatic injuries is the chance of aseptic pulp necrosis to occur which in time may became infected and give origin to periapical pathosis. Although the apical granulomas and cysts are a common condition, there appearance as an extremely large radiolucent image is a rare finding. Differential diagnosis with other radiographic-like pathologies, such as keratocystic odontogenic tumour or unicystic ameloblastoma, is mandatory. The purpose of this paper is to report a very large radicular cyst caused by a single mandibular incisor traumatized long back, in a 60-year-old male. Medical and clinical histories were obtained, radiographic and cone beam CT examinations performed and an initial incisional biopsy was done. The final decision was to perform a surgical enucleation of a lesion, 51.4 mm in length. The enucleated tissue biopsy analysis was able to render the diagnosis as an inflammatory odontogenic cyst. A 2 year follow-up showed complete bone recovery.

Primeiro pré-molar superior com três canais: diagnóstico e tratamento - quatro casos clínicos

Resumo Apesar da presenca de dois canais radiculares ser a anatomia mais comum nos primeiros pre-molares superiores, derivacoes anatomicas para um e tres canais estao tambem descritas. Um correcto conhecimento das diversas morfologias, uma correcta analise radiografica e auxiliares de ampliacao potenciam o sucesso nestes casos. O objectivo deste texto e, apresentando uma serie de casos clinicos, contribuir para o melhor conhecimento e abordagem deste tipo de situacoes clinicas.

3D Visual Glossary of Terminology in Root and Root Canal Anatomy

The study of dental anatomy, physiology, and occlusion provides one of the basic components of the skills needed to practice all phases of dentistry. The first step in understanding dental anatomy is to learn the nomenclature and terminology used to describe or classify the material included in this subject. While terminology is an established basis for communication, anatomical terminology serves as a base for the description of the human body, not only for educational and forensic purposes but, above all, for diagnostic and therapeutic procedures. Therefore, definitions and explanations of terms used in descriptive root and root canal anatomy are the foundation for understanding the subject matter presented in the other chapters of this book. The purpose of this chapter is to use 3D high-resolution images to illustrate and define several terminologies associated with root canal anatomy.