Metal Artifact Reduction in Oral Cavity MDCT Using Dental Overlays and the O-MAR Algorithm

Abstract

Background/Objectives: To evaluate the impact of dental laboratory material overlays on metal artifact reduction in multidetector computed tomography (MDCT) of the oral cavity across different CT protocols and reconstruction algorithms. Methods: An anthropomorphic mandible phantom was constructed using extracted human teeth, metal-ceramic restorations, and ballistic gelatin as a soft-tissue analog. Six dental materials (Elite HD+, Vonflex S Putty, Tropicalgin, MB Wax 1, Zetaplus, and COE-PAK) were tested as overlays. MDCT imaging was performed following low-dose and standard protocols with primary and O-MAR reconstructions, yielding 28 datasets. Two radiologists independently assessed artifact indices (AIs), overall image quality (OIQ), and spherical marker visibility (SMV), with excellent inter-observer agreement (ICC = 0.985). Results: Vonflex S Putty model consistently demonstrated the lowest AIs and highest OIQ scores, while maintaining stable performance across both protocols and reconstructions. Elite HD+ and Zetaplus also showed favorable results, while COE-PAK and MB Wax 1 frequently underperformed. Tropicalgin exhibited high AIs with primary reconstruction but improved markedly with O-MAR. SMV analysis confirmed Vonflex S Putty as the only material to consistently outperform the control under low-dose conditions. Conclusions: Silicone-based overlays, particularly Vonflex S Putty, are effective in reducing metal artifacts and improving image quality in MDCT. Overlay selection, combined with MAR algorithms such as O-MAR, represents a complementary strategy for optimizing diagnostic accuracy in patients with metallic restorations.