Detectability of chemically induced periapical lesions by limited cone beam computed tomography, intra-oral digital and conventional film radiography.

Objective: Our aim was to compare the Accu-I-Tomo (3DX), the Digora Optime image plate system and F-speed film in detecting chemically created apical lesions.

Methods: Lesions were created by applying perchloric acid apical to extracted teeth in jaw specimens for 1, 1.5 or 2 h. After being repositioned, teeth were radiographed with Accu-I-Tomo limited cone beam CT (LCBCT), Digora Optime storage phosphor plates (SPP) and F-speed films. Six observers scored the presence of lesions using a five-grade scale. The accuracy of each observer and modality was assessed through receiver operating characteristic (ROC) analysis and A(z) values were compared using two-way ANOVA. Pairwise comparisons of imaging systems were carried out using the Mann-Whitney U-test. Differences in A(z) values were compared using Friedman and Dunn's tests. Kappa (kappa) was used to measure interobserver agreement.

Results: The A(z) values were larger for LCBCT than for SPP and film for all acid durations. For 1 h of acid duration a significant difference was found between LCBCT and film (P = 0.02) and between LCBCT and SPP (P = 0.0043), For 1.5 h a significant difference (P = 0.006) was found between LCBCT and SPP only. For 2 h acid duration, there was no significant difference between LCBCT and film or SPP (P>0.05). Between SPP and film no significant difference was found for any acid duration (P>0.05). kappa ranged between fair and moderate for LCBCT and between slight and fair for SPP and film.

Conclusion: LCBCT images provided better than or similar detectability as film and SPP images of chemically created periapical lesions.