(PR47) Analysis of Teeth with Prior Endodontic Treatment Referred for Cone Beam Computed Tomography Imaging

Objective: To evaluate salient features of endodontically treated teeth referred for cone-beam computed tomography (CBCT) imaging. Material and

Methods: The source population included consecutive patients referred for CBCT imaging over an 18-month period for various indications. Subgroup of interest comprised previously treated teeth. A 25% random sample (n=94) was selected for this analysis. Specific features of tooth and prior endodontic treatment were tabulated in terms of median (IQR) or frequencies/percentages as appropriate. We evaluated the associations of specific variables with the type of canal using regression methods.

Results: Based on periapical index (PAI) scoring 90.4% of teeth had apical periodontitis. Resorption overall was present in 16% of cases, including apical infection-induced resorption (47%) and external resorption (27%). Overall frequency of missed canals was 28.7%, the highest being MB2 (78%). A total of 29 teeth (31%) had sealer extrusion, most frequently in palatal canal (9/29 teeth, 31%). 10 teeth (11%) had root filling overextension, the highest in palatal canal (4/10 teeth, 40%). The root filling level ranged from 0 to 1.31.mm from the apex and varied significantly according to type of canal, MB2 being the highest (median 1.31. mm, IQR 1.08-2.02), p = 0.012. Good density was present in 40 teeth (43%), fair in 29 (31%) and poor in 23 (25%). The most frequent type of restoration was crown with a build-up (55/94 teeth, 58%) and post in 26 teeth (28%).

Conclusion: Endodontically treated teeth referred for CBCT imaging exhibit high rate of apical periodontitis and characteristic pattern of resorption.