title: Influence of translucence/opacity and shade in the flexural strength of lithium disilicate ceramics.
abstract: BACKGROUND
  Lithium disilicate ceramic system consists of glass ceramic ingots with different grades of translucence which may influence its flexural strength.
  
  
  OBJECTIVE
  To assess the three-point flexural strength of the different lithium disilicate-based ceramic ingots (IPS e.max Press/Ivoclar Vivadent) with different levels of translucence and shade.
  
  
  METHODS
  Six groups of ceramic ingots were selected to represent different levels of translucence and shade (HTA1, HTBL2, LTA2, LTB2, MO2, and HO). They measured 25 mm × 5 mm × 2 mm (n = 10), according to ISO 6872 specifications, and tested on a universal test machine (EMIC).
  
  
  METHODS
  A one-way analysis of variance (ANOVA) was used (α = 0.05).
  
  
  RESULTS
  The results (in MPa) were: HTA1 = 392.98; HTBL2 = 390.74; LTA2 = 390.46; LTB2 = 389.92; MO2 = 390.43; HO = 391.96. ANOVA showed no significant difference among groups (P = 0.1528).
  
  
  CONCLUSIONS
  Different levels of translucence, opacity and shade of ingots did not affect their mechanical strength, and the use of these ceramics should be guided by the esthetic demands of each clinical situation.
authors.affiliation: Department of Dental Prostheses, São Leopoldo Mandic Dental Research Institute, School of Dentistry, Rua José Rocha Junqueira, 13, Bairro Swift, Campinas, SP, Brazil.
authors.forename: Mila Oliveira
authors.initials: MO
authors.lastname: Santos
authors.affiliation: Department of Restorative Dentistry, São Leopoldo Mandic Dental Research Institute, School of Dentistry, Rua José Rocha Junqueira, 13, Bairro Swift, Campinas, SP, Brazil.
authors.forename: Flávia Lucisano Botelho
authors.initials: FL
authors.lastname: do Amaral
authors.affiliation: Department of Restorative Dentistry, São Leopoldo Mandic Dental Research Institute, School of Dentistry, Rua José Rocha Junqueira, 13, Bairro Swift, Campinas, SP, Brazil.
authors.forename: Fabiana Mantovani Gomes
authors.initials: FM
authors.lastname: França
authors.affiliation: Department of Restorative Dentistry, São Leopoldo Mandic Dental Research Institute, School of Dentistry, Rua José Rocha Junqueira, 13, Bairro Swift, Campinas, SP, Brazil.
authors.forename: Roberta Tarkany
authors.initials: RT
authors.lastname: Basting
keywords: Ceramics; compressive strength; lithium compounds