Résumé
Background and Aim: Selecting the appropriate form of anterior teeth in patients without teeth is important factor in restoring the missing beauty of the patient. For this purpose, the study of natural teeth in terms of investigating the relationship between dimensions and forms and its prevalence in the Iranian community is essential
Materials and Methods: This analytic and descriptive study was done with participation of 300 eligible patients and students with different genders. Where a maxillary impression was taken and poured in yellow stone. They were measured for length and 3 horizontal distances on the upper incisor consisting of cervical width, middle width and incisal width, by digital caliper with 0.01mm accuracy, and the prevalence of tooth form determined. Normal distribution variables were analyzed with logistic regression
Results: Analysis indicated that Average length and width of the maxillary central incisor in order is 9.12 +/- 0.87 mm and is 8.44 +/- 0.59 mm and average ratio of length and width is 0.92 =/- 0.08 mm Horizontal and vertical dimensions of the clinical crown in the men slightly more than women, and the prevalence of tooth form thus obtained: oval incisior [53%], tapered-square [21.3%], tapered [16.7%], and square [9%]. A significant correlation only could be shown between shape and width [p<0.05]
Conclusion: With increasing the width of the central maxillary tooth, oval shape was observed more frequently than square form. Meantime of choosing dental form, oval form considered more because of its high incidence
Résumé
Root canal obturation seals the root canal system to prevent re-entry and/or growth of microorganisms. The provision of an appropriate restoration to coronally seal the access cavity affects the success of endodontic treatment. The purpose of this study was to evaluate the coronal microbial leakage in root canals that were either filled by lateral compaction, GuttaFlow or warm vertical compaction. In this ex vivo study, 80 single-rooted human extracted teeth were randomly divided into three experimental groups [n=20] and two positive and negative control groups [n=10]. The teeth in experimental groups were obturated with cold lateral compaction, GuttaFlow system or warm vertical compaction techniques. After sterilization of the whole system with gamma-ray, saliva leakage was tested using a split-chamber model. Specimens were monitored every 24 hours for 30 days. The data were analyzed using log-rank and Kaplan-Meier survival analysis tests. There were no significant differences in impeding saliva leakage between the three experimental groups [P>0.05]. Under the conditions of this ex vivo study, it can be concluded that the sealing ability of cold lateral compaction, warm vertical compaction and GuttaFlow system was comparable
Résumé
The aim of this in vitro study was to compare the effectiveness of three intracanal medicaments in disinfecting the root canal and dentin of experimentally infected human teeth with Enterococcus faecalis [EF]. One hundred extracted human single-rooted teeth were used. After root canal preparation, teeth were mounted in epoxy resin. Following sterilization, the teeth were infected for 28 days with EF. Then root canals were filled with one of three different disinfectants: viscous 2% Chlorhexidine [CHX], calcium hydroxide paste [CH] or a mixture of CH and CHX [n=30 in each group]. Antimicrobial assessments were performed at 1, 3 and 7 days [n=10 in each time period]. Microbial samples were obtained from root canals before and after the experiment. Also dentin samples were examined. The data was analyzed using Two- Way ANOVA test. The findings showed that there was no difference between experimental groups at different time periods. The mixture of CH/CHX in 7 days was able to eliminate EF completely from root canal system. The most elimination of EF was from dentinal tubules. According to the results of this in vitro study, viscous 2% CHX, mixture of CH with distilled water and 2% CHX are all effective disinfectants