Prevalence of missed canals in endodontically treated teeth: A cone-beam computed tomography study.

Background: This study aimed to measure the prevalence of untreated root canals and periapical lesions in endodontically treated teeth using cone-beam computed tomography (CBCT) and their association with the coronal seal. Material and Methods: This cross-sectional study assessed CBCT images of studied patients alongside documented information from their dental examinations. The assessment method for analyzing CBCT images after including endodontically treated teeth was the presence of missed canals, and periapical lesions were analyzed in three dimensions. Results: The evaluations from 772 teeth demonstrated that 89.4% of teeth had the proper coronal seal, 13.3% owned missed root canals, and 29.4% had periapical lesions. Most untreated canals belonged to maxillary first molars (71.8%) and mandibular lateral incisors (33.3%). The prevalence of periapical lesions was highest in mandibular lateral incisors (58.3%) and maxillary second molars (55.8%). In teeth with missed canals, the most periapical lesions were observed in the first premolars of both jaws. In teeth with the lack of proper coronal seal, the periapical lesions were observed in 55.6% of teeth with untreated root canals. Conclusions: The results revealed a high prevalence of missed canals and periapical lesions in endodontically treated teeth in our study population. Key words:Untreated Root Canals, Periapical Lesions, 3-D Dental Imaging, Dental Treatment Failure.

Dentine Thickness of Second Mesibuccal Canals in First Maxillary Molars Prepared with Rotary Instruments.

Introduction: The purpose of this study was to evaluate the thickness of the remaining dentine wall in the danger zone of the second mesiobuccal (MB2) canals using cone-beam computed tomography (CBCT) in maxillary first molars following preparation by means of HERO 642 rotary instruments with different tapers. Methods and Materials: The study samples included twenty-five mesiobuccal roots of maxillary first molars. A two-step method was employed to prepare the MB2 canals applying HERO 642 instruments: using a 0.02 taper (step 1), and a 0.04 taper (step 2). The roots were scanned before preparation, and after each step. The thickness of the dentine wall was recorded at the CEJ level, as well as 2 mm and 4 mm below the CEJ. The repeated-measures ANOVA in conjunction with the Cochran tests were used to compare the changes in the thickness of the root canal wall. Results: There was no area with dentine thickness of <0.5 mm before preparation. A significant reduction in dentine thickness occurred following the preparation with both 0.02 and 0.04 files at all three levels compared with the pre-instrumentation values (P< 0.05). However, areas with dentine thickness of < 0.5 mm after preparation using 0.04 files were significantly more than those resulting from the application of 0.02 files both at the CEJ and 2 mm-below-CEJ points, but the differences were not significant at the 4mm-below-CEJ level. Conclusion: Within the limitations of the present in vitro study, the use of larger taper instruments in MB2 root canals of maxillary first molars increased the quantity of samples with dentine thickness less than 0.5 millimeter at the coronal level of the root canal. It was concluded that instruments with large tapers, should be used with caution in troughing or preparing such root canals to reduce the risk of strip perforation.

Postendodontic Pain after Pulpotomy or Root Canal Treatment in Mature Teeth with Carious Pulp Exposure: A Multicenter Randomized Controlled Trial.

This equivalence, randomized, clinical trial aimed to compare the postoperative pain of root canal therapy (RCT) with pulpotomy with mineral trioxide aggregate (PMTA) or calcium-enriched mixture (PCEM) in permanent mature teeth. In seven academic centers, 550 cariously exposed pulps were included and randomly allocated into PMTA (n = 188), PCEM (n = 194), or RCT (n = 168) arms. Preoperative "Pain Intensity" (PI) on Numerical Rating Scale and postoperative PIs until day 7 were recorded. Patients' demographic and pre-/intra-/postoperative factors/conditions were recorded/analysed. The arms were homogeneous in terms of demographics. The mean preoperative PIs were similar (P=0.998), the mean sum PIs recorded during 10 postoperative intervals were comparable (P=0.939), and the trend/changes in pain relief were parallel (P=0.821) in all study arms. The incidences of preoperative moderate-severe pain in RCT, PMTA, and PCEM arms were 56.5%, 55.7%, and 56.7%, which after 24 hours considerably decreased to 13.1%, 10.6%, and 12.9%, respectively (P=0.578). The time span of endodontic procedures was statistically different; RCT = 69.73, PMTA = 35.37, and PCEM = 33.62 minutes (P < 0.001). Patients with greater preoperative pain, symptomatic apical periodontitis, or presence of PDL widening suffered more pain (P=0.002, 0.035, and 0.023, resp.); however, other pre-/intra-/postoperative factors/conditions were comparable. Pulpotomy with MTA/CEM and RCT demonstrate comparable and effective postoperative pain relief.

Resolved Tooth Discolouration Following Root Fracture Employing a Conservative Approach: A Case Report.

Dental trauma is one of the most common childhood incidents that leads to the damage or loss of deciduous and permanent teeth. One of the most challenging types of dental trauma is horizontal root fracture (HRF). In this case report, a central maxillary incisor with horizontal root fracture had been treated by the conservative approach of splinting the tooth and follow-up. In the initial evaluation, the tooth had a normal appearance and did not respond to either the cold test or electric pulp tester. After 4 weeks, the tooth was sensitive to the cold test; however, showed discolouration. After 4 months, discolouration disappeared and the tooth had a positive response to pulp sensibility tests. The tooth remained asymptomatic with a positive response to pulp sensitivity tests up to 15 months following the treatment.

Successful Ultra-Conservative Management of a Mandibular Premolar with Dens Invaginatus.

Dens invaginatus is one of the most common anomalies of tooth structure. It is caused by the invagination of the crown surface during odontogenesis that enters the pulp chamber of the affected tooth. Depending on the complexity of invagination, the tooth might present with pulp necrosis, open apex and a complicated root canal system. This case report presents an Oehlers' type 2 dens-invaginatus in a mandibular premolar with chronic apical abscess. In most cases, dens invaginatus is removed during treatment. However, in this case report, based on cone-beam computed tomography (CBCT) evaluation, non-surgical treatment and maintenance of the invaginated segment was chosen in order to prevent compromising the tooth structure and its susceptibility to future root fracture. This is a new treatment approach and has not been performed in previous reports. Calcium-enriched mixture (CEM) cement was used as an apical plug followed by gutta-percha in warm vertical compaction for root canal obturation. The case was followed up for 36 months after treatment. This report highlights the importance of selecting the appropriate treatment approach based on CBCT evaluation.