title: Silica coating on alumina ceramic: comparison of three chairside air-abrasion devices working for different times and distances.
abstract: OBJECTIVE
  This study evaluated, by scanning electron microscope (SEM) and EDS, the effect of different strategies for silica coating (sandblasters, time and distance) of a glass-infiltrated ceramic (In-Ceram Alumina).
  
  
  METHODS
  Forty-one ceramic blocks were produced. For comparison of the three air-abrasion devices, 15 ceramic samples were divided in three groups (N.=5): Bioart, Microetcher and Ronvig (air-abrasion parameters: 20 s at a distance of 10 mm). For evaluation of the time and distance factors, ceramic samples (N.=5) were allocated in groups considering three applied times (5 s, 13 s and 20 s) and two distances (10 mm and 20 mm), using the Ronvig device. In a control sample, no surface treatment was performed. After that, the micro-morphologic analyzes of the ceramic surfaces were made using SEM. EDS analyzes were carried out to detect the % of silica on representative ceramic surface. ANOVA and Tukey tests were used to analyze the results.
  
  
  RESULTS
  One-way ANOVA showed the silica deposition was different for different devices (P=0.0054). The Ronvig device promoted the highest silica coating compared to the other devices (Tukey test). Two-way ANOVA showed the distance and time factors did not affect significantly the silica deposition (application time and distance showed no statistical difference).
  
  
  CONCLUSIONS
  The Ronvig device provided the most effective silica deposition on glass-infiltrated alumina ceramic surface and the studied time and distance for air-abrasion did not affect the silica coating.
authors.affiliation: Department of Dental Materials and Prosthodontics, São José dos Campos Dental School, São Paulo State University at São José dos Campos, Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Pestana Passos
authors.forename: A
authors.initials: A
authors.lastname: Dias Vanderlei
authors.forename: M
authors.initials: M
authors.lastname: Ozcan
authors.forename: L F
authors.initials: LF
authors.lastname: Felipe Valandro
authors.forename: L
authors.initials: L
authors.lastname: Felipe Valandro
mesh_terms: D020906:Air Abrasion, Dental / Q000295:instrumentation* / Q000379:methods*; D002516:Ceramics; D012822:Silicon Dioxide; D013997:Time Factors
chemical_list: D012822:Silicon Dioxide