A Novel Apparatus to Standardize the Polishing Protocol to Achieve Different Roughness of Titanium and Zirconia Disc Surfaces.

Abstract

To propose and evaluate standardized polishing protocols for in vitro experiments using a custommade apparatus under controlled force to create consistent surface roughness on titanium and zirconia discs. A total of 160 discs were manufactured with a diameter of 10 mm, 80 titanium (Ti) and 80 zirconium oxide (Zr). Specimens were categorized into two groups: controlled force (CF) and without controlled force (WCF). Specimens in the CF group were polished with a custom apparatus incorporating a tension gauge on the Ti and Zr disc surfaces to achieve consistent roughness. The WCF group was polished without the use of a tension gauge. Each group had four subgroups (n = 10): control/machined with no polishing (C), rough (R), smooth (S), and very smooth (VS). The subgroups were processed using a sequence of diamond-impregnated polishing burs and polishing paste. The CF group showed consistent surface roughness and a gradual decrease in surface roughness. Control in Ti (Ra = 6.5 ± 0.03 μm) and in Zr (Ra = 5.4 ± 0.04 μm); R in Ti (Ra = 3.5 ± 0.06 μm) and in Zr (Ra = 3.2 ± 0.07 μm); S in Ti (Ra = 1.5 ± 0.04 μm) and in Zr (Ra = 1.1 ± 0.06 μm); and VS in Ti (Ra = 0.05 ± 0.002 μm) and in Zr (Ra = 0.02 ± 0.005 μm). There were significant differences for R, S, and SV under CF and WCF in Ti and Zr surfaces. The specimens polished under control force produced significantly more uniform surface roughness than those polished without controlled force and were produced with a higher degree of consistency.