The effects of different implant crown restorative materials on the detection of proximal caries of adjacent teeth in cone-beam computed tomography (CBCT) scans using various machines, metal artifact-reduction (MAR) algorithm, and exposure protocols.

Background: This study aimed to investigate how artifacts from different restorative materials affect the detection of approximal caries in CBCT scans, using various machines, artifact-reduction (AR) algorithms, and exposure protocols. Material and Methods: Ten permanent teeth (5 molars, 5 premolars) were selected and categorized into 3 intact and 7 with artificial carious lesions. The teeth were arranged in a human mandible with an ingot of material in-between and in the following approximal surfaces configurations: intact-ingot-intact, caries-ingot-caries, and intact-ingot-caries/caries-ingot-intact. Three different ingot materials were used (3Y and 5Y Zirconia, and E-Max) and the setup was scanned using two CBCT systems (Planmeca Mid and Prexion) with varying exposure protocols, with and without AR algorithm, thus resulting in 90 scans. Three observers of different experience levels evaluated the images and P and Kappa values were calculated. Results: Kappa and P values showed a significant positive association with the AR option, and a negative association without AR for zirconia 5Y. Zirconia 3Y had the highest positive association across all observers using both low and standard exposure settings on the Prexion®. The inter-observer agreement was insignificant, while intra-observer agreement was highly significant. Conclusions: The AR option improves the accuracy of approximal caries detection in CBCT scans for materials with higher yttria concentration but has no significant effect on lower yttria materials. The Prexion® scanner outperformed the Planmeca ProMax 3D Mid® in caries detection without AR.