Comparison of accuracy of Cone-Beam Computed Tomography subtraction radiography and Digital Intra-oral subtraction radiography in determininig bone demineralization

Abstract

Introduction: Osteoporosis is a silent, complex, multifactorial, and chronic disease characterized by a gradual decrease in bone density. Therefore, early diagnosis is essential in the treatment and prevention of fractures. In this cross-sectional study, the accuracy of the differential method of CBCT (Cone-Beam Computed Tomography) and Digital Intra-oral imaging in the diagnosis of osteoporosis was investigated. The aim of the present study was to determine and compare the accuracy of two different methods: CBCT subtraction radiography and digital Intra-oral subtraction radiography in detecting bone demineralization. Methods & Materials: The bone specimen used in this design was the calf mandible bone with teeth. To simulate osteoporosis, the samples were immersed in 5% acetic acid for 6 days(144 hours). Once every 12 hours, the samples were removed from the acid and washed with distilled water and in the following, they were radiographed with the help of the two mentioned imaging systems. With the help of measurement software of each system, bone density was evaluated in 12 different defined regions. Finally the images were subtracted and the comparison of the accuracy of two systems was analyzed by the statistical method Chi-Square test. Results: Based on the change detection rate in the samples during the studied times, which were calculated according to Fisher and Chi-square tests, at the 12th hour of the study (image no. 2 or variable t12), the change detection rate with the subtractive CBCT method was equal to 33.33% and with the subtractive Digital Periapical method was equal to 0%, which based on the tests performed, this difference was not statistically significant(p-value=0.09). Next, the detection rate of changes in other time variables was also measured, and according to the results of the tests, there was no statistically significant difference between the two imaging methods in any of the study hours. The number of diagnoses recorded in subtractive CBCT radiography was 73 and in Digital Periapical subtraction radiography was 52 during 144 hours of study. The median change detection time in the CBCT subtraction radiography and Digital Periapical subtraction radiography groups were 84 (120-42) and 72 (120-36), respectively, which was not statistically significant based on the non-parametric Mann-Whitney test(p-value=0.88) Conclusion: CBCT subtraction radiography showed early changes in bone density compared to digital periapical subtraction radiography and was also able to detect more changes (in terms of the number of recordable changes) than digital periapical method. CBCT subtraction radiography can be considered as a reliable technique to evaluate changes in bone density. However, digital periapical subtraction radiography can also be used.