The aim of this study was to determine the effect of autoclave polymerization on the transverse strength of denture base polymers. To this end, 30 rectangular test specimens were fabricated of two heat-polymerized denture base polymers. The test groups were: (I) control, i.e., conventional water bath to polymerize resins by heat at 100°C for 30 minutes; (II) autoclave polymerization at 60°C for 30 minutes followed by 130°C for 10 minutes; and (III) autoclave polymerization at 60°C for 30 minutes followed by 130°C for 20 minutes. The specimens were tested with three-point bending test at a crosshead speed of 5 mm/min. It was revealed that the transverse strength of specimens increased with statistical significance when the autoclave was used for polymerization.

Objective: To evaluate the effect of chlorhexidine-thymol varnish alone, its combination with chlorhexidine-fluoride containing dentifrice and fluoride varnish on oral hygiene and caries prevention in orthodontic patients. Study design: Sixty patients, aged 12-18, with orthodontic fixed appliances were randomly assigned into three groups as follows: Group 1 (n=20): 1% chlorhexidine and 1% thymol varnish (Cervitec®Plus); Group 2 (n=20): Cervitec®Plus+ 0.2% chlorhexidine and 0.2% sodium fluoride (900 ppm fluoride) (Cervitec®Gel)); and Group 3 (n=20): 0.1% fluoride varnish (Fluor Protector®). Mutans streptococci (MS), lactobacilli (LB) levels, buffering capacity (BC), visible plaque index (VPI), and gingival bleeding index (GBI) scores were evaluated at four stages: T0, before orthodontic bonding; T1, one week after orthodontic bonding; T2, one week; and T3, four weeks after the first application, respectively. Inter and intra group comparisons were made by the Kruskal-Wallis, Mann-Whitney U, Friedman and Wilcoxon Signed-Rank tests with Bonferroni step-down correction (P<0.017). Results: Significantly lower MS and LB levels were found in Group 2 than Group 1 (T2) and 3 (T2, T3) (P<0.017). Groups 1-2 (T2) showed significantly higher BC (P<0.017) and lower VPI and GBI (P<0.017) scores compared with Group 3. Decreased MS levels at T2 (P<0.017) and T3 (P>0.017) were found in Group1-2 compared with T0. Significantly lower LB levels were recorded in Group 2 at T2 compared with T0 (P<0.017) while no significant differences were seen in Group 1 and 3 (P>0.017). Conclusions: Addition of Cervitec®Plus+Cervitec®Gel combination to the standard oral hygiene regimen may be beneficial for orthodontic patients for maintaining oral health by reducing bacterial colonisation and gingivitis. Key words:Chlorhexidine, flouride, mutans streptococci, lactobacilli, antibacterial effect, plaque, gingivitis, orthodontic treatment.

Within the limitations of this study, it can be suggested that autoclave postpolymerization is an effective method for increasing the fracture toughness of tested autoploymerized acrylic resins.

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The present study aimed to measure and compare anatomic parameters in contralateral maxillary second molars. A total of 18 intact maxillary second molar pairs (n = 36) extracted from 18 patients were scanned with micro-computed tomography (micro-CT) and then reconstructed. Axial, sagittal, and cross-sectional slices were used to analyze the parameters (lengths, widths, and thicknesses) and evaluate the symmetry of the right and left sides. The number of root canals and their internal patterns were classified following Vertucci’s classification. The number of lateral canals and their locations were also noted. Contralateral second molar pairs demonstrated a high degree of similarity in terms of the linear measurements (lengths, widths, and thicknesses). The root canal anatomy configuration symmetry of mesiobuccal, distobuccal, and palatal roots according to Vertucci’s classification were 41.1%, 88.2%, and 94.4%, respectively. In total, 41.6% of mesiobuccal roots, 2.7% of distobuccal roots, and 30.6% of palatal roots had at least one lateral canal. The apical third (38.7%) was the most frequent location of lateral canals, followed by the middle third (32.3%) of the root. This study provides insight into the anatomy of the root canals of contralateral maxillary second molars, which is valuable for both practitioners and researchers.

Craniofacial clefts are extremely rare deformities. Tessier’s classification is a widely accepted system that is based on clinical, radiographical, and surgical observations. The Tessier No. 0 cleft most commonly affects the upper lip, nose, and palate. This case presentation aims to report the outcome of a modified presurgical alveolar molding (PAM) appliance used in the treatment of an infant with Tessier No. 0 cleft as an alternate approach to mold such defects before surgery. The modified PAM appliance consisted of reciprocal parts connected by a helix. The segments were approximated by stripping the appliance at the midline in a V-shaped manner and the force was exerted by the extraoral elastics. The procedure gave results in 8 weeks, which may be regarded as a reasonable duration. The anterior cleft gap, which was 13 mm before the treatment, was reduced to 3 mm after the treatment by using modified PAM appliance. On a 21-month follow-up period, oral reshaping was regarded successful due to stability of the improved oral mold.

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