Radiographic Evaluation of Current Restorative CAD/CAM Ceramics Indicated for Fabrication of Indirect Restoration.

Objectives: To measure and compare the radiopacity values of available computer-aided design/computer-aided manufacturing (CAD/CAM) restorative materials used for the fabrication of long-term single-tooth indirect restorations.

Materials and methods: 1 and 2 mm thick samples (n = 10 per material) were fabricated from different CAD/CAM materials, including glass-matrix (VITA mark II, Empress CAD, VITA Suprinity, Celtra DUO, and e.max CAD), polycrystalline (3Y zirconia, Katana HTML Plus), and resin-matrix ceramics (VITA Enamic, Lava Ultimate, Flexcera Smile Ultra Plus, Sprintray Ceramic Crown, VarseoSmile TriniQ, and Rodin Sculpture 2.0). The samples were placed on a digital X-ray sensor along with an aluminum step wedge and a tooth section with similar thickness. The gray scale value was measured in Image J software and converted to mmAl using Curve Expert Pro 2.7 software. Data were analyzed with a two-way ANOVA and post hoc Tukey tests, with the significance level set at 95% (α = 0.05).

Results: Type of restorative material and thickness had a significant effect on the radiopacity values (p < 0.05). Radiopacity of all tested materials was similar to (Sprintray Ceramics Crown, p > 0.05) or significantly higher (p < 0.05) than the radiopacity of the dentin, except for VITA Mark II, VITA Enamic, Flexcera Smile Ultra Plus, and VarseoSmile TriniQ, which had a significantly lower radiopacity than dentin (p < 0.05).

Conclusion: Radiopacity of evaluated CAD/CAM materials was significantly different. The highest radiopacity was observed in zirconia, and the lowest radiopacity was found in Flexcera Smile Ultra Plus.

Clinical significance: Radiopacity of most of the tested CAD/CAM materials was equal to or higher than that of dentin with a similar thickness. However, VITA mark II, VITA Enamic, Flexcera Smile Ultra Plus, VarseoSmile TriniQ had lower radiopacity than dentin and their radiographic evaluation would be dependent on the radiopacity of the cement for detection of recurrent caries. Understanding the radiopacity of each CAD/CAM material helps clinicians select the appropriate material and helps them detect the type of restorative material.