Estimation of the annual cumulative radiation dose received by the dentist in dental clinics in Chennai

Abstract

Aim and Objectives: To estimate the annual cumulative radiation dose received by a dentist in a 'less than an ideally sized clinic' in Chennai. The objective of the study is to estimate the annual cumulative radiation dose received by the dentist at various distances and various angulations from the x-ray tube. Study Design: The head of a mannequin model was mounted on the dental chair to simulate a patient's head and three thermoluminescent dosimeter (TLD) chips were kept at various distances and various angulations, at a constant height. The standard conventional intraoral dental radiographic unit was used, which was kept stationary, with a constant voltage of 70 Kv, 8 mA current, and a constant exposure time of 0.3 seconds. Ninety-two TLD chips were exposed 20 times a day with constant horizontal angulations for a period of one year. The reading from the TLD chips was obtained on a computer through a TLD Badge Reader. Statistical Analysis: Post Hoc tests and One-way analysis of variance (ANOVA) were used. Results and Conclusion: A decreasing trend was obtained in the average radiation doses, as the distance increased from the x-ray source, and a highly significant difference in doses (P < 0.001%) was found between 4 and 5.5 feet (ft). We found a minimum average radiation dose at an angle of 60° to 80° and behind the tube. The purpose of this study was to create awareness among dental professionals, who had 'less than an ideally sized clinic'. We recommend that the dentist follow guidelines suggested by the National Council on Radiation Protection and Measurements (NCRP), USA. From this study, it is clear that most clinics are of sizes that do not permit this distance (6 ft), and hence, it is recommended that they use suitable barriers.