Barrel media hardness on polishing and surface roughness of dental resin materials

Stereolightho graphy (SLA) digital light processing (DLP) [6].3D Purpose: This study aimed to assess the effect of the hardness of dental barrel finishing media on the polishing amount and surface roughness (Ra) of different resin materials.Methods: Two types of media (Gray [G] and Pink [P]) and three types of resin (thermal po- lymerization resin [denture base, DB], autopolymerization resin [orthodontic appliance, OA], and photopolymerization resin for three-dimensional printing [crown & bridge, CB]: Vertex Rapid Simplified, Vertex Dental; Ortho-Jet, Lang Dental; Tera Harz TC-85DAC, Graphy) were used.The hardness values of the media and resin specimens were measured.The specimens were barrel-polished at a speed of 450 rpm for 25 minutes, and their weight loss was recorded.The change in Ra values was assessed.Results: The polishing amount was the highest in the G group among all three resins.The lowest Ra value was recorded in the DBP group at 0.210.01m; however, no significant differences were observed between the samples in either group (p>0.05). Conclusion:High-hardness G media are suitable when high polishing rates and efficiency are required.However, its performance may decline in the presence of substantial hardness mismatch with low-hardness workpieces.Conversely, low-hardness P media demonstrates excellent performance in fine surface polishing and is suitable for achieving smooth and uniform surface finish.