Comparative Radiopacity of Additively Manufactured Permanent and Temporary Resins and Conventional Resin‐Based Composites

OBJECTIVE: This study aimed to evaluate whether radiopacity differs among additively manufactured permanent resins, temporary resins, and conventional resin-based composites at clinically relevant thicknesses. MATERIALS AND METHODS: Eight dental materials were evaluated and categorized into four groups: additively manufactured permanent resins (VarseoSmile Crown Plus, Saremco Print CrownTec), additively manufactured temporary resins (Arma Resin TEMP Teeth, Alias Temp C&B), conventional self-cure resin-based composites (Stela Automix, Stela Capsule), and conventional light-cure resin-based composites (Gradia Posterior, G-ænial Injectable). Rectangular specimens (5 × 5 mm) were fabricated at two standardized thicknesses (1 and 2 mm) (n = 10). Extracted human tooth sections and a 21-step aluminum wedge were used as reference standards. Radiographic images were obtained using a digital intraoral radiography system, and radiopacity values were measured in mmAl using ImageJ software. Statistical analysis was performed using Kruskal-Wallis, Dunn-Bonferroni, and Mann-Whitney U tests (α = 0.05). RESULTS: Significant differences in radiopacity were observed among the tested materials (p < 0.05). Additively manufactured temporary resins demonstrated the lowest radiopacity values, whereas conventional resin-based composites exhibited the highest radiopacity. Permanent additively manufactured resins showed intermediate radiopacity values. Increasing specimen thickness from 1 to 2 mm significantly increased radiopacity values for all materials (p < 0.001). Several temporary additively manufactured materials presented radiopacity values lower than dentin and enamel. CONCLUSION: The findings suggest that radiopacity varies significantly among restorative materials and is influenced by specimen thickness. In particular, the relatively low radiopacity of some additively manufactured resins may limit their radiographic detectability, which should be considered during material selection in clinical practice. CLINICAL SIGNIFICANCE: Radiopacity differences among restorative materials may influence the detection of recurrent caries and restoration margins. Lower radiopacity of some additively manufactured resins highlights the importance of careful material selection for accurate radiographic diagnosis.