Background: This study assessed the effect of propolis and 2% chlorhexidine (CHX) on push-out bond strength of fibre post-cemented with resin cement.Materials and Methods: This in-vitro, experimental study evaluated 36 extracted human mandibular premolars in three groups (n=12). After root canal cleaning and shaping, propolis and 2% CHX gel were applied as an intracanal medicament in groups 1 and 2, respectively. Group 3 received no medicament. The access cavity was sealed, and the teeth were incubated for one week. The root canals were obturated and post space was prepared using the #2 Angelus drill. After 72 h of incubation, the crowns were cut, and the roots were mounted in acrylic and incubated for one week. The roots were sectioned into apical, middle and coronal thirds and underwent a push-out test. Data were analyzed using ANOVA and Bonferroni and Tukey’s tests.Results:Thepropolis group showed maximum and minimum bond strength in the middle and coronal thirds, respectively (P>0.05). The CHX group showed the highest and the minimum bond strength in the coronal and middle thirds, respectively (P>0.05). The control group showed maximum and minimum bond strength in the middle and coronal thirds, respectively (P>0.05). The mean bond strength in the propolis group was significantly higher than the control group (P<0.05).Conclusion: usingpropolis as intracanal medicament can increase the push-out bond strength of fibre post-cemented with resin cement in the middle third of the root while using CHX increases the push-out bond strength of fibre post in the coronal third. تفاصيل المقالة

Background: Errors that occur during root canal treatment can be caused by lack of information about the anatomical conditions of the root canal system. The purpose of this study was to examine the root and ca-nals morphology of mandibular anterior teeth using cone-beam computed tomography (CBCT). Materials & Methods: In this descriptive analytical study, 165 CBCT images of mandibular anterior teeth of patients from 15 to 60 years in the archives from oral & maxillofacial radiology department in 2015-2021 were used. CBCT images were examined in three axial, sagittal and coronal sections and the infor-mation of each tooth were recorded in pre-prepared forms. The data were analysed by Chi-square and Fisher exact test (α=0.05). Results: All mandibular central teeth were single-rooted, of which 59.7% were single canal and 40.3% were double-canal. 99.4% of the mandibular lateral teeth were single-rooted and 0.6% of the teeth were double-rooted. 62.8% of single-rooted laterals had a single-canal where 37.2% had double-canals. 97.6% of canine teeth were single-rooted and 2.4% of teeth were double-rooted. In single-rooted teeth, 95.3% had a single-canal. In mandibular single-rooted anterior teeth with two canals, Vertucci type III was the most common configuration. The frequency distribution of the variation of mandibular central and lateral teeth canals between women and men were not statistically significant, while in single-rooted canines significant differ-ences were observed (p= 0.031). Conclusion: Anterior teeth with two roots was not common. It was more prevalent in canines, laterals and central teeth. The prevalence of single-rooted mandibular teeth with two canals was mostly seen in central, lateral, and canine teeth. تفاصيل المقالة