Journal of Dental Medicine

Background and Aims: Estimating the canal length is essential for reaching to a proper endodontic treatment. Any error and miscalculation in estimation of the working length, especially in curved canals, can result in complication during and after root canal therapy. The introduction of digital radiography has enabled us to measure curved canal length. The purpose of this study was to evaluate the calibration tool of Complementary Metal Oxide Semiconductor (CMOS) digital system in estimation of working length.

Materials and Methods: In this in-vitro study, 80 extracted molar teeth were selected and randomly divided into three groups based on angle and radius of canal curvature. A 5 mm orthodontic wire was placed on the lateral surface of the root. Conventional radiographs were taken after insertion of endodontic file in the apical third of root canals. Radiographic images were scanned and imported to the software of CMOS digital system. Two observers estimated the file lengths with and without using calibration tool of digital measurement software. The correlation between observers was evaluated and then data were analyzed using Paired T-test with 95% confidence.

Results: Overall agreement between observers was good. There was no significant difference between the mean values of calibrated measurement and true file length in the basis of canal curves (P>0.001). However, there was significant difference between the mean values of uncalibrated measurement and true file length in the basis of canal curvature (P<0.001).

Conclusion: The calibrated measurement of file length was more accurate than that of the uncalibrated file length measurement.

Background and Aims: Human ergonomics or engineering with proper design and change of work and requirements creates the most productivity based on human physiology. The purpose of this study was to determine the level of awareness of dental students of Isfahan University of Medical Sciences about the basic principles of ergonomics in dentistry.
Materials and Methods: In this descriptive-analytical, sectional study, a questionnaire containing 10 questions was distributed and completed by easy sampling method among 74 final year students of the general doctorate of Isfahan school of dentistry. After collecting the questionnaires, the students were given an educational pamphlet. To evaluate the questionnaires, each correct answer was given a score of one and the wrong answers were given a score of zero. Data were analyzed by T-test, Kai Square, and Mann-Whitney statistical tests using SPSS23 software. P<0.05 was considered as a significant level. P<0.05 was considered as a significant level.
Results: The average score of the knowledge of principles of ergonomics was intermediate (6.23±1.25). Student knowledge was not significantly different based on the student gender (P=0.25) and academic semester (P=0.059). Also, 55% of students had a history of muscle pain that did not have a significant relationship with gender (P=0.258) and average score of the knowledge (P=0.288).
Conclusion: Unfortunately, ergonomics cannot be considered part of the principles of dental education and even later. Musculoskeletal pain is one of the most common complaints of dentists and is a factor in reducing their quality and function. Therefore, it seems that training and evaluation of ergonomic principles in dental education is necessary.

Background and Aims: Periapical diseases are the end result of untreated pulpitis and necrotic dental pulp. The aim of this study was to determine and compare the prevalence of radicular cysts and periapical granulomas in young adults and old patients referred to Oral Pathology department of Isfahan dental school.
Materials and Methods: In this cross-sectional study, all recorded samples with a diagnosis of radicular cyst and periapical granuloma were considered by the census method in a 14-year period from 2006 to 2019 in the archives of the Oral Pathology Department of Isfahan dental school. The data were extracted including age, gender, location of the lesion and histopathologicaldiagnosis.
The prevalence of cases in terms of age range was classified into two groups of young adults (20-35 years) and older (over 50 years). Then, Chi-square test and t test were done using SPSS24 and P<0.05 was considered significant.
Results: The results showed that 49.4% (430 cases) of lesions were observed in males and 50.5% (439 cases) in females. Of all lesions, 51% (444 samples) were periapical granulomas and 49% (426 samples) were radicular cysts. Chi square test showed a significant difference between the prevalence distribution of the two lesions based on gender. Radicluar cysts were more prevalent in males and periapical granulomas were more prevalent in females (P<0.001). According to t-test, there was no significant difference between the mean age of patients based on gender (P=0.176). The prevalence of lesions in the third and fourth decades of life was higher than in other decades. Also, in the third and eighth decades, the prevalence of periapical granulomas was higher than radicular cysts.
Conclusion: The prevalence of periapical cysts and dental granulomas were higher in young adults than in elderly patients.