title: Systematic approach to preparing ceramic-glass composites with high translucency for dental restorations.
abstract: OBJECTIVE
  Ceramic composites are promising materials for dental restorations. However, it is difficult to prepare highly translucent composites due to the light scattering that occurs in multiphase ceramics. The objective of this work was to verify the effectiveness of a systematic approach in designing specific glass compositions with target properties in order to prepare glass infiltrated ceramic composites with high translucency.
  
  
  METHODS
  First it was necessary to calculate from literature data the viscosity of glass at the infiltration temperature using the SciGlass software. Then, a glass composition was designed for targeted viscosity and refractive index. The glass of the system SiO2-B2O3-Al2O3-La2O3-TiO2 prepared by melting the oxide raw materials was spontaneously infiltrated into porous alumina preforms at 1200°C. The optical properties were evaluated using a refractometer and a spectrophotometer. The absorption and scattering coefficients were calculated using the Kubelka-Munk model.
  
  
  RESULTS
  The light transmittance of prepared composite was significantly higher than a commercial ceramic-glass composite, due to the matching of glass and preform refractive indexes which decreased the scattering, and also to the decrease in absorption coefficient.
  
  
  CONCLUSIONS
  The proposed systematic approach was efficient for development of glass infiltrated ceramic composites with high translucency, which benefits include the better aesthetic performance of the final prosthesis.
authors.affiliation: Center for Engineering, Modeling and Applied Social Science, Universidade Federal do ABC, Av. dos Estados, 5001, Santo André, SP 09210-580, Brazil. Electronic address: humberto.yoshimura@ufabc.edu.br.
authors.forename: Humberto N
authors.initials: HN
authors.lastname: Yoshimura
authors.affiliation: Center for Engineering, Modeling and Applied Social Science, Universidade Federal do ABC, Av. dos Estados, 5001, Santo André, SP 09210-580, Brazil.
authors.forename: Afonso
authors.initials: A
authors.lastname: Chimanski
authors.affiliation: Department of Biomaterials and Oral Biology, School of Dentistry, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Paulo F
authors.initials: PF
authors.lastname: Cesar
mesh_terms: D002516:Ceramics / Q000138:chemical synthesis*; D003764:Dental Materials / Q000138:chemical synthesis*; D008027:Light; D008422:Materials Testing; D016062:Porosity; D013053:Spectrophotometry / Q000379:methods
chemical_list: D003764:Dental Materials; C023506:Glass ceramics
keywords: Ceramic–glass composites; Dental ceramics; Glasses; Infiltration; Optical properties