Artifacts infuence on proximal caries diagnosis with CBCT images

Abstract

The purpose of this work was to analyze the influence of artifacts generated by almalgam restorations on proximal caries diagnosis. Fourteen healthy human premolars were poditioned in pairs on blocks made with heavy silicone keeping their proximal contact points. Class II amalgam restorations in each proximal surface were performed followed by proximal caries which were simulated in the interface between the tooth cervical limit and the amalgam restoration with a spherical low speed drill n. 1. The conventional radiographs were taken with Insight KodakTM films, time exposure of 0.5 s and focal distance of 25cm. The CBCT images were taken with the Newtom 3G (ImageWorksTM) scanner with FoV 6 and high resolution. All conventional radiographs and CBCT images were taken before and after the amalgam restorations and the simulated proximal caries have been done, making possible three differents moments of evaluation as follow: M0 (healthy teeth), M1 (teeth with only amalgam restorations) and M2 (teeth with amalgam restorations and simulated proximal caries). All conventional radiographs and CBCT images were assessed with a lightbox and the Dental Slice (ImageWorksTM) software in a dark room by one observer, respectively. The results were categorized and analyzed using the statistical test of the difference between two proportions. It was observed that at onset moment (M0), conventional radiographs images showed a higher percentage of correct answers in relation to the CBCT images. For the first and second moments of evaluation (M1 and M2), there was no significant difference between the number of correct answers and the number of observations in the radiographs and CBCT images. The influence of artifacts generated by radiopaque structures such as amalgam, on proximal caries located in the interface between the tooth cervical limit and the amalgam restoration seem not to be significant on CBCT images.