The Ra values of both polished and glazed groups significantly increased after immersion in orange juice and cola (P0.05). Conclusion Orange juice and cola significantly increased the surface roughness of both polished and glazed ZLS ceramics. Type of surface finishing (polishing versus glazing) had no significant effect on the surface roughness of specimens following immersion in different beverages. Copyright© Dental Research Center, Tehran University of Medical Sciences.Objectives Attempts to retain primary teeth have led to introduction of materials and techniques for their preservation such as stainless steel crowns (SSCs). Due to variations in tooth anatomy among different populations, this study compared the buccolingual (BL) to mesiodistal (MD) ratio of primary mandibular first molars with that of SSCs in an Iranian population. https://www.selleckchem.com/products/PCI-24781.html Materials and Methods This cross sectional study was conducted on 96 primary mandibular first molars with intact cementoenamel junction, which had been extracted for severe caries. The MD and BL dimensions of the teeth and available maxillary and mandibular SSCs (3M) were measured. Two independent examiners measured the dimensions twice at two different time points using a digital caliper. Data were analyzed by one-sample t-test and McNemar's test via SPSS 21.0 software. Results Significant differences were observed in both BL and MD dimensions between teeth and both maxillary and mandibular SSCs (P less then 0.001). According to McNemar's test, the dimensions of 65.6% of teeth matched those of mandibular SSCs while the dimensions of 38.5% matched those of maxillary crowns. Dimensions of 3.1% of the teeth did not match any of the crowns and in 7.4%, both maxillary and mandibular SSCs were appropriate. Conclusion Comparing the variances of BL/MD ratio of teeth with SSCs revealed that the dimensions of two-thirds of the teeth matched those of mandibular SSCs, while the maxillary SSCs were appropriate for the remaining one-third. Significant differences were seen between the size of teeth and both maxillary and mandibular crowns. Copyright© Dental Research Center, Tehran University of Medical Sciences.Objectives This study sought to assess the thickness of buccal and lingual alveolar bone plates according to the position of impacted mandibular third molars on cone-beam computed tomography (CBCT) scans. Materials and Methods Eighty-four CBCT scans of impacted mandibular third molars were evaluated in this retrospective study. All images had been obtained by ProMax 3D CBCT system with the exposure settings of 78 kVp, 12 mA, 16 s time, 0.2 mm voxel size and 10 × 9 cm field of view. The impaction angle of teeth and the thickness of buccal and lingual cortical plates were determined on images by drawing lines in the anterior, middle, posterior, superior, central and inferior regions. Thickness of bone plates was analyzed according to the position of impacted molars relative to the buccal and lingual plates using the Student t-test and relative to the second molars using one-way ANOVA and Tukey's test. Results In the buccolingual direction, the buccal plate thickness was maximum in lingual position followed by central position, and minimum in buccal position of the teeth. The lingual plate thickness was minimum in horizontal and distoangular positions and maximum in the mesioangular position of impacted teeth. Conclusion Risk of lingual plate preformation is higher in surgical removal of impacted third molars with distoangular and horizontal positions. Thus, further attention must be paid by the surgeons to such cases. Copyright© Dental Research Center, Tehran University of Medical Sciences.Objectives This study aimed to compare the transportation of the mesiobuccal canal of maxillary molars following root canal preparation with HyFlex CM (HCM) and Edge Taper Platinum (ETP) rotary systems and stainless steel (SS) hand files using cone-beam computed tomography (CBCT). Materials and Methods This in-vitro study was performed on 48 maxillary molars in three groups of 16. The teeth were mounted in acrylic blocks, and root canals were prepared using HCM in group 1 (up to #30/0.06), ETP in group 2 (up to F3/0.06), and SS hand files in group 3 (up to #30). CBCT scans were taken before and after root canal preparation. The amount of canal transportation was measured at 0, 3, 6, and 9mm from the apex. Data were analyzed using Kruskal-Wallis and Mann-Whitney tests. Results The difference in canal transportation at 0 and 6mm from the apex was significant between the HCM and ETP groups (P=0.031 and 0.023) but none of the systems showed any significant difference with hand files at 0-and 6-mm levels (P=0.10, 0.56, 0.22, and 0.50), respectively. At 3mm from the apex, no significant difference was noted among the groups (P=0.30). At the 9-mm level, the amount of canal transportation was not significantly different between HCM and ETP (P=0.83) but they showed significant differences with hand files (P less then 0.001). Conclusion ETP and HCM caused less canal transportation at the curvature of the mesiobuccal canal of maxillary molars compared to hand files. ETP showed superior efficacy in root canal preparation compared to HCM. Copyright© Dental Research Center, Tehran University of Medical Sciences.Objectives The aim of this study was to compare the microshear bond strength (μSBS) of various adhesive systems to dentin. Materials and Methods In this in vitro experimental study, 60 sound human third molars were divided into four groups. Dentin discs were prepared of middle-third dentin measuring 4 mm in diameter and 2 mm in thickness. Dentin surfaces were bonded with one of the four types of adhesives (A) Single Bond (3M ESPE), Scotchbond Universal (3M ESPE) in etch and rinse (B) and self-etch (C) modes and (D) Clearfil SE Bond (Kuraray Noritake Dental). After the application of adhesive systems according to the manufacturers' instructions, composite cylinders (Vit-l-escence) were bonded to dentin surfaces. The μSBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). Results The μSBS was the highest in self-etch Scotchbond Universal (15.8±6.08 MPa) followed by Clearfil SE Bond (15.24±4.6 MPa), etch and rinse Scotchbond Universal (11.