Root canal configuration of one-rooted mandibular canine in an iranian population: an in vitro study

A perfect endodontic treatment necessitates proper understanding of the morphology of canal and pulpal variations. This in vitro study was conducted to demonstrate the internal anatomy of mandibular canine teeth in an Iranian population. The samples consisted of 100 extracted mandibular permanent canines. The roots of the teeth were molded in acrylic boxes. The crowns of the teeth were cut and 2 mm cross sections were made from CEJ to the apex. Sections were examined using stereomicroscope to reveal the number and location of root canals. From 100 evaluated teeth, 12 [12%] had 2 canals from which 5 had type II canal configuration and 7 [7%] had type III. 88% of the specimens had one canal and none were seen to be of type IV. The findings of this study emphasize the importance of dentist's knowledge of variations in root canal morphology, since leaving a canal untreated is one of the main reasons of endodontic failures. When treating mandibular canines, the existence of a second canal should be taken into consideration

Evaluation of x-ray protection methods used in dental offices in Tabriz in 2005-2006

The aim of this study was to evaluate x-ray protection methods in dental offices in Tabriz. In this study 142 dental offices were evaluated. A questionnaire-based method was used. The data was analyzed by descriptive methods. The least commonly used methods were leaded walls [4.9%] and film badges [16.9%] and the most commonly used methods were lead partitions [67.6%] and position-distance rule [68.3%]. The most commonly used patient protection devices were E-speed films [84.5%] and long collimators [66.2%]. The least commonly used methods, in this respect, were automatic processors [2.1%] and rectangular collimators [0%]. Regarding protection methods for the patient, results did not conform to international standards. Mostly, manual processing was used, resulting in extra radiation dose to patients. The methods which reduce the received dose of patients were disregarded in offices compared to educational centers, necessitating optimization of educational programs in these fields

Influence of the display monitor on observer performance in detection of dental caries

Digital imaging continues to gain acceptance in dentistry and video display used for this becomes important. The aim of this study was to assess the influence of the display monitor on observer performance on caries detection. Artificial enamel lesions were created in 40 extracted teeth at random using 1/4 and 1/2 round burs. Teeth were mounted in dental stone blocks to simulate a hemi-dentition. Approximate exposures were recorded at 70 kVp using a Planmeca [Planmeca Co, Helsinki, Finland] digital imaging system. Three oral and maxillofacial radiologists rated each image on a five-point scale for the presence or absence of lesion. Radiographic images were viewed on the following monitors: [1] LG Flatron 700p [LG Electronics Co., South Korea]; [2] Samsung Magicgreen [Samsung Electronics Corp., South Korea]; [3] Hansol 710p [Hansol Electronics Corp., South Korea] and [4] Toshiba satellite laptop [Toshiba Computer Corp., Philippines]. Examiners were allowed to magnify and adjust density and contrast of each image at will. Receiver Operating Characteristic [ROC] analysis was performed. Data was subjected to repeated measures analysis of variance and ordinal logistic regression to test for significance between variables and to determine odds ratios. Mean ROC curve areas ranged from 0.8728 for the LG monitor to 0.8395 for the Samsung. Repeated measures analysis of variance showed significant differences between observers [P < 0.0001], lesion size [P < 0.0001], examiner/monitor interaction [P < 0.033] and examiner/block interaction [P < 0.013]. However, no significant difference was found between monitors. This study suggests that observer performance is independent of the visual characteristics of the display monitor