title: Effects of surface-finishing protocols on the roughness, color change, and translucency of different ceramic systems.
abstract: BACKGROUND
  Surface-finishing protocols have a mechanical impact on ceramic surfaces that could eventually affect surface topography and light scattering. An optimum protocol is needed to avoid damaging the optical properties of ceramics.
  
  
  OBJECTIVE
  The purpose of this study was to determine the effects of different surface-finishing protocols on the surface roughness, color change, and translucency of ceramic and metal ceramic restorations.
  
  
  METHODS
  Standardized disk-shaped specimens (1.5 × 10 mm, n=128) were fabricated from 3 different ceramic core materials (aluminum oxide [Al2O3]-AL, zirconium oxide [ZrO2]-ZR, lithium disilicate [Li2Si2O5]-LIT), veneered (V) with dentin ceramics (n=32 per group), and placed in the following groups: ALV, ZRV, and LITV. The metal ceramic group acted as the control (n=32). Four different surface-finishing methods were tested. Airborne-particle abrasion with 50 μm Al2O3, polishing with adjustment kit, polishing with adjustment kit plus diamond polishing paste, and autoglazing (n=8 subgroup) were applied on the veneering ceramics. The specimens were analyzed with a profilometer for surface roughness, and color change and translucency were measured with a clinical spectrophotometer. Statistical analyses were performed with 1-way ANOVA and the Tukey honest significant difference tests (α=.05).
  
  
  RESULTS
  Specimens treated with the airborne particle abrasion method showed significantly higher mean profilometer for surface roughness values in all groups (P<.05). The polishing with adjustment kit and autoglazing methods revealed statistically similar surface roughness values in all groups (P>.05). With the diamond polishing paste method, lower surface roughness values were achieved in the ZRV and metal ceramic groups acted as the control groups. Different surface-finishing methods affected the color change of the ceramic systems, except for ZRV. Surface-finishing protocols significantly affected the translucency values of the ALV, LITV, and metal ceramic groups (P<.05).
  
  
  CONCLUSIONS
  No single surface-finishing protocol can be recommended to obtain the smoothest surface and the least color change without affecting translucency for the ceramics tested. The airborne-particle abrasion protocol created rougher surfaces and decreased translucency, and color change in zirconia was not affected by the finishing protocols.
authors: Associate Professor, Ege University, Atatürk Medical Technology Vocational Training School, Izmir, Turkey.
authors: Gülcan Coşkun
authors: GC
authors: Akar
authors: Associate Professor, Dumlupinar University, Faculty of Dentistry, Kutahya, Turkey. Electronic address: gurelp@gmail.com.
authors: Gürel
authors: G
authors: Pekkan
authors: Professor, Ege University, Faculty of Dentistry, Department of Prosthodontics, Izmir, Turkey.
authors: Ebru
authors: E
authors: Çal
authors: Professor, Yuzuncu Yil University, Faculty of Dentistry, Department of Prosthodontics, Van, Turkey.
authors: Gürcan
authors: G
authors: Eskitaşçıoğlu
authors: Professor, University of Zurich, Center for Dental and Oral Medicine, Dental Materials Unit, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich, Switzerland.
authors: Mutlu
authors: M
authors: Özcan
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D003116:Color; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000295:instrumentation / Q000379:methods*; D003776:Dental Porcelain / Q000737:chemistry; D003801:Dental Veneers; D018130:Diamond / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D008027:Light; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D013053:Spectrophotometry; D013499:Surface Properties; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D003764:Dental Materials; C508050:IPS e.max Press; D016876:Metal Ceramic Alloys; C493120:lithia disilicate; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D015019:Yttrium; D018130:Diamond; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide