Surface roughness and gloss comparison of CAD/CAM resin-based composite crowns polished with various systems.

OBJECTIVES: The aim of this study was to investigate the surface roughness and gloss of maxillary central incisor crowns fabricated from CAD/CAM resin-based composite after polishing with six different polishing systems. METHOD AND MATERIALS: One hundred and five maxillary central incisor crowns (n = 15 per group) were milled from a CAD/CAM resin-based composite material (Cerasmart) and divided into seven groups according to the polishing protocol: (1) Shofu Composite Polishing; (2) DiaComp; (3) OptraGloss Composite Polishing; (4) Dialite LD; (5) OptraFine; (6) Dialite ZR; and (7) no polishing (control). Surface roughness (Ra) and gloss of the facial surface of each crown were evaluated using a contact profilometer and a glossmeter. A noncontact optical profilometer was used to obtain 3D surface topography images. RESULTS: Polishing significantly reduced surface roughness and increased gloss compared with unpolished crowns. Among the polishing systems evaluated, OptraFine produced the smoothest surfaces, followed by OptraGloss, Dialite LD, Shofu Composite, and DiaComp. The highest gloss values were observed for OptraFine, followed by Dialite LD, Shofu Composite, OptraGloss, Dialite ZR, and Dia- Comp. Unpolished crowns exhibited the highest surface roughness and the lowest gloss. CONCLUSION: Ceramic and composite polishing systems significantly reduced surface roughness and increased gloss for CAD/CAM resin-based composite crowns compared with unpolished crowns. Among the ceramic and composite polishing systems evaluated, OptraFine produced the smoothest surfaces, while OptraFine and Dialite LD achieved the highest gloss values.