Efficacy of CBCT Images for the Evaluation of Periapical Lesions

Objective: To help endodontists select the correct treatment plan (surgical/non-surgical) based on periapical lesion size using the most appropriate imaging modality that will prevent significant morbidity (more so if the treatment is surgical) and reduce treatment costs significantly. Methods: This is a clinical research study involving observers (endodontists) who compared intra oral Periapical (PA) x-rays and Cone Beam Computed Tomography (CBCT) images to make treatment decisions (surgical or non-surgical) on periapical lesions measuring more than three millimeters in size. Twenty patients with a carious tooth and symptoms of a periapical lesion presented to the Endodontic clinic who participated in the study. Digital sensors were used to obtain PA x-rays and a conventional CBCT scanner for CBCT images. Six observers were selected for viewing periapical and CBCT images and each image modality was viewed for the following criteria: a. Identify periapical lesion on image corresponding to particular study tooth (present/absent) b. Measure extent of periapical lesion at greatest dimension – length and diameter of lesion (with “ruler” in software tool) c. Assess degree of radiolucency (used already established PAI (Peri Apical Index) scores for conventional radiography and CBCT) d. Expansion of periapical cortical bone (Absent/Present) e. Destruction of periapical cortical bone (Absent/Present) f. Treatment decision of particular study tooth Results: Characteristics of each of the PA and CBCT images as scored by observers were compared using ANOVA statistics. The CBCT images were found to alter treatment decisions by more than 50% after the observers initially reviewed the PA images. Inter-observer and Intra-observer agreements were also calculated. Conclusion: CBCT images provide more information to help with treatment decisions. However, future studies with a larger sample size is recommended to advocate the use of CBCT as a routine imaging technique for making treatment decisions on endodontically treatable periapical lesions.