Prevalence and Size of Periapical Radiolucencies Using Cone-beam Computed Tomography in Teeth without Apparent Intraoral Radiographic Lesions: A New Periapical Index with a Clinical Recommendation

Abstract

IntroductionThe purpose of this study was to determine the prevalence and size of periapical radiolucencies using cone-beam computed tomographic (CBCT) imaging in teeth without apparent signs of intraoral radiographic lesions. MethodsOne hundred twenty roots from 53 patients who had been determined to have no signs of intraoral radiographic lesions were included in this study. Limited-volume CBCT scans were taken at 0.125-mm3 voxel size. The widest area of apical radiolucency of each root canal–treated tooth was measured and assigned a numeric score based on the CBCT-Endodontic Radiolucency Index (ERI). CBCT data were evaluated by 2 radiologists with an interclass correlation coefficient of 0.96. ResultsThe majority of roots (53.3%) had periodontal ligament widths ≤0.5 mm; 26.7% had radiolucency widths of 0.5 < x ≤ 1 mm, 15.0% had radiolucency widths of 1.0 < x ≤ 1.5 mm, 0.8% had radiolucency widths of 1.5 < x ≤ 2.0 mm, 1.7% had radiolucency widths of 2.0 < x ≤ 2.5 mm, and 2.5% had radiolucency widths of >2.5 mm. Patient age, recall interval, tooth type, and arch type had no statistically significant effect on the ERI distribution. ConclusionsTwenty percent of teeth with successful root canal treatment based on conventional periapical imaging had CBCT radiolucencies measuring greater than 1 mm. Because these radiolucencies may not be pathological changes, clinicians are cautioned against overtreatment of them before determining the true nature of these findings. Clinical studies with long follow-up times are needed to determine the proper course of actions for these cases.