Observers Agreement in Perception of Non-Cavitated Approximal Dental Caries by Intraoral Digital CCD Radiography at Different Exposure Parameters and Corresponding Required Radiation Dose

Abstract

Objectives: To evaluate the diagnostic accuracy of Charged Coupled device (CCD) in detection of Non- Cavitated Approximal caries at different exposure parameters in relation to radiation dose in vitro. Study Design: Seventy-eight surfaces of extracted teeth were inserted in acid gel to create non-cavitated proximal caries with different depth, and then Radiographs have been taken to all teeth by CCD sensor. Radiographs were interpreted by three observers. The lesions were classified as (N) No lesion, (D1) Less than ½ enamel thickness, (D2) more than halfway of enamel but not involve DEJ. (D3) Dentin caries. Teeth were randomly selected for histological analysis after consensus from three oral and maxillofacial radiologists as Gold standard. The corresponding radiation dose was measured by unfors meter device at different exposure parameters. Results: The histological examination showed that the distribution of lesions was 39.8% Sound, both enamel lesions are equal 17.8%, Dentin lesions 24.6. The sensitivity and specificity of CCD to detect normal surfaces were 0.95, D1 was 0.37, D2 was 0.74 and D3 was 0.86. As the lesions depth increased, the sensitivity increased. The higher image quality was produced by using exposure parameters (70 KvP, 160 ms) and (70 KvP, 200 ms). While, (60 KvP, 200 ms) and (60 KvP, 250 ms) produced the worse image quality. Conclusion: Regard the balance between the higher diagnostic accuracy of digital images and minimum radiation dose: using exposure parameters as (70 KvP, 160 ms) is considered the best image quality and relative dose (81 mSv). While, (70 KvP, 125ms) and (66 KvP, 160 ms) are little bit lower quality and corresponding dose are (63), (73) respectively. Although (70 KvP, 200 ET) produce higher image quality but its relative dose is high (101mSv).