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"nBackground and Aim: The role of applying rotary instruments in reducing preparation time and proper root canal preparation have been approved in permanent teeth. The aim of this study was to compare the rotary instruments (Hero642) and K-files in root canal preparation of primary molars. Time and canal transportation were compared. "nMaterials and Methods: In this experimental, invitro study, 30 human extracted primary molars with 8 mm length were selected and divided into two equal groups. After preparing access cavity, group 1was prepared by K-files and group 2 by Hero642 systems. Before canal preparation, with # 15 K-file and after canal preparation, with master apical file, canal curvature was evaluated by Weine technique using Radiovisiography. Apical transportation was calculated. Time taken for preparation was recorded by chronometer. The results were analyzed with T-test and Mann-Whitney. P

Statement of Problem: Dental age estimation methods are used in treatment plan and the identification of the age of unknown corps and skulls. One of the methods of age estimation is Foti method which is based on regression analysis of dental variables (number of tooth germs and erupted tooth) for which four models have been proposed. Purpose: The aim of the present study was to compare the dental age derived from these four methods with the Demirjian method on the basis of chronological age. Methods and Material: In this cross-sectional descriptive study, 150 panoramic radiographs of 90 girls and 60 boys aged 6-20 years were studied. The variables required for regression analysis were derived from clinical examinations and panoramic radiographs. Demirjian age was determined using panoramic radiographs. Results: The mean chronological age was 10.74±3.02, Demirjian age 11.16, ± 2.76, model one 11.57±1.61, two 11.44±2.35, three 11.53± 2.49 and four was 11.24±1.85 years. The comparison between chronological age, Demirjian age and regression models showed a statistically significant difference. The obtained ages from Demirjian methods and regression models were showed to be overestimated. Conclusion: A positive association was found between the real ages and age estimates derived from these four models. The equations allow age estimation in specific situations (such as when only either the maxillae or mandible is available or when the radiography is not available). [ABSTRACT FROM AUTHOR]

An abstract of the article "Sealant Microleakage Evaluation of Three Common Fissure Preparation Methods," by Sh. Javadinejad, D. Ghasemi Toodeshki, and A. Salehi is presented.