Introduction: An important issue in treatment planning and endodontic treatment is to deal with sophisticated internal dental morphology. Deviations from normal anatomy in maxillary molars are usually related to the number of canals in mesiobuccal root. Although unusual anatomy is not uncommon in maxillary molars, the occurrence of 3 separate canals with distinct orifices and apical foramina (as we see in this case) is extremely rare. Getting familiar with this unusual anatomy helps clinicians to treat patients more efficiently with less chance of failure.Case Presentation: This case report describes a successful endodontic management of an uncommon variation of the maxillary first molar with a third mesiobuccal canal. The tooth had a deep carious lesion and the pulp was irreversibly damaged causing pain on the left side of the face. The periodontium was normal. The tooth received root canal treatment and 400 mg ibuprofen was prescribed every 6 hours for 2 to 3 days. The patient remained asymptomatic and the 3-month follow-up radiograph revealed normal periodontium.Conclusions: Inability to identify and treat additional canals that are very common in the MB root of maxillary first molar could lead to treatment failure.

Background: The root canal morphology of teeth is often extremely complex. Of particular interest is the complexity of mesiobuccal root of maxillary first molar.Objective: The purpose of this study was to evaluate the root canal configuration of maxillary first permanent molar in a part of population of Qazvin.Methods: In this descriptive-analytic study, 114 extracted maxillary first permanent molar were collected from different dental clinics in Qazvin. The crowns of all specimens were sectioned from the CEJ. The teeth with depressions on their mesiobuccal roots and with two separate orifices and two apical foramens were selected. On these specimens, the length of mesiobuccal roots in buccal and palatal aspects, the length of mesiobuccal and mesiopalatal canals, and the maximum mesiodistal width (in three parts: midroot, 1 millimeter apical and coronal to the midroot) of buccal and palatal aspects of mesiobuccal root were measured using a micrometer. Indian ink was injected into the pulp system of all mesiobuccal roots. The specimens were rendered clear by demineralization, dehydration, and immersion in methyl salicylate. The evaluation of root canal system was based on Vertucci's classification. Data were analyzed using SPSS version 12 and T test.Findings: The mean length of mesiobuccal roots in buccal and palatal aspects and the mean length of mesiobuccal and mesiopalatal canals were 14.30, 13.34, 14.84, and 14.09, respectively.Statistically, there was a significant difference in length between the buccal and palatal aspects (p<0.000).Also, the mean mesiodistal width of midroot, 1 millimeter apical and coronal to the midroot, in buccal and palatal aspects of mesiobuccal root were 3.09, 3, 3.26, 2.24, 2.11, and 2.31 millimeters, respectively. Similarly, a statistically significant difference in width between the buccal and palatal aspects was found, (p<0.000).Based on Vertucci's classification, the mesiobuccal root canal anatomical system consisted of 21.9% as type 1, 58.8% type II, 0.8% type III, 21% type IV, 2.6% type V, and 2.6% type VI.Conclusion: Based on data found in our study, a considerable variety of root canal configurations were found in mesiobuccal root of maxillary first molars. The mesiobuccal root often contains a double root canal system.

Introduction: The second canal of the mesiobuccal root (MB2) of the maxillary first molars (MFM) is difficult to detect in conventional radiographs and can be a major cause of failure in endodontic treatments. The aim of this study was to investigate the prevalence and anatomy of the MB2 by using high-resolution cone-beam computed tomography (CBCT). Methods and Materials: Three radiologists examined 414 high-resolution CBCTs. Of these, the CBCTs of 287 patients (mean age 49. 43± 16. 76) who had at least one MFM were selected, making a total of 362 teeth. Prevalence and its relation with gender and age of the patients, side of the tooth, and Vertucci’ s classification were analyzed. Data were statistically analyzed (P<0. 05). Results: A total of 68. 23% of the teeth exhibited the MB2. The presence of the MB2 was equivalent in both genders and significantly higher in younger patients. There was no correlation between the presence of the MB2 in relation to both the sides of the MFM and the FOV size. Smaller FOV recognized higher Vertucci’ s grades. Conclusions: It was concluded that the prevalence of the MB2 canal in maxillary first molars in this Brazilian population examined with high-resolution CBTCs is 68. 23%, being more prevalent in young patients. Gender and the side examined are no factors for determining the presence of MB2. Although the both FOVs of the high-resolution CBTCs (FOV 8 and 5) detect the MB2 canal, smaller FOV (FOV 5) is more accurate in the analysis of the internal anatomy of such root canals, according to the Vertucci´ s classification.

Background and Objectives: The anatomy of maxillary molars is very complicated and root canal therapy for this specific group of teeth is a major challenge for dentists. Given the limitations of conventional techniques for finding the second mesiobuccal canal (MB-2) and anatomical differences observed in different ethnicities, this study aimed to determine the anatomy of mesiobuccal root canal in maxillary first permanent molars using CBCT (Cone-beam computed tomography) in Rafsanjan city. Materials and Methods: In this descriptive study, 41 promax 3D CBCT radiographs of patients in Rafsanjan in 2018 were studied. To investigate the root morphology, after obtaining multiple planar reformation (MPR) images in sagittal and axial planes, evaluation was done by Vertucci classification. Data were analyzed using chi-square test or Fisher’ s exact test. Results: Of the 41 studied films, one canal was observed in mesiobuccal root in 15 (36. 6%) films and two canals in the others 26 (63. 4%) films. Among the roots containing two canals, second type of Vertucci classification was the most common type observed. It should be noted that there was no significant relationship between the number of canals and also the type of canals and gender (p=0. 495 and p=0. 583, respectively) and with quadrant of the tooth (respectively p=0. 133 and p=0. 669). Conclusion: According to the results of the present study and the amount of two-canal mesiobuccal roots, it can be said that the preparation of CBCT film before root canal therapy in maxillary first molar is necessary to verify the existence and type of MB-2 canal.

Background: One of the main reasons for the failure of root canal treatment is the incomplete knowledge of the root canal system. With respect to the complexity of maxillary molars root canal system, and the possibility of the relationship between the buccolingual width of the mesiobuccal root and root canal morphology in maxillary molars, the aim of this study is to determine this relationship with cone‑, beam computed tomography (CBCT). Materials and Methods: This in vitro study carried out on 311 CBCT scans. Maxillary first molars (n = 311) were evaluated in three sagittal, axial, and coronal planes. For each tooth the number of canals, presence of second mesiobuccal (MB2), buccolingual width of mesiobuccal root at the cementoenamel junction (CEJ), and mid‑, root level, and type of canals according to the Vertucci’, s classification were determined. Results: The results showed that 49. 1% of first maxillary molars had 3 and 50. 8% had four root canals. The most common canal type in the mesiobuccal root was Vertucci’, s Type I followed by Types II, IV, and V. The prevalence of MB2 in the Iranian subpopulation was 50. 1%. In maxillary first molars with MB2, the buccolingual width of mesiobuccal root at the CEJ and mid‑, root level (P < 0. 001) was significantly greater than the corresponding values in other one without MB2. Conclusion: The results showed that the buccolingual width of mesiobuccal root in maxillary first molars at the CEJ level and mid‑, root was correlated with the number of root canals.

Purpose: The antibacterial activity of three endodontic sealers, a Ca (OH)2 based sealer (apexit) a Zoe based sealer (Drofill) and a resin based sealer (AH26) was assessed on the growth of an anaerobic bacteria (peprostreptococcus spp.) using the Agar diffusion test (ADT). Materials and Method: Thirty brain heart diffusion agar plates were incubated with peptostreptococcus anaerobics. Each plate was divided into two separate areas. In one area, 0.1ml droplet of a given fresh sealer and in the other area a dry material of the same sealer were placed, such that each plate had two areas with the same sealer in two forms of fresh and dry (setform). There were ten plates for each of the three sealers. The plates were placed into anaerobic jars and incubated at 37oC. After varying periods, zone of inhibition of bacterial growth were observed, measured and compared by t and Paired T-test.Results: There was no statistically significant differences between the activity of AH26 and drofill in the fresh form(P>0.05). However there were significant differences between (the two sealers in set form) (P<0.05) Drofill was more antibacterials in the set form than AH26. All sealers were more active when fresh than ages.Conclusion: It is likely that the eugenol in the Dorifill and the formaldehyde in the AH26 are responsible for their greater antimicrobial activity.