title: A meta-analysis of the most indicated preparation design for porcelain laminate veneers.
abstract: OBJECTIVE
  To evaluate the fracture strength of three different types of tooth preparation design for ceramic veneers and determine whether there is any correlation between the preparation performed and the type of failure observed, by means of a meta-analysis of published in vitro studies.
  
  
  METHODS
  Three databases were consulted to select the studies, considering previously established inclusion and exclusion criteria. The data extracted were submitted to statistical analysis by means of the software Review Manager 5.1, using the random effect statistical model with a confidence interval of 95%.
  
  
  RESULTS
  The results showed a decrease in mean dental fracture strength of 76.53 N in teeth with feathered incisal edge preparations, and 102.82 N for those with palatal chamfers when compared with nonprepared teeth, whereas the preparation with a butt joint showed no significant difference compared to nonprepared teeth (p = 0.37). Ceramic fractures occurred more frequently in the chamfer type than feathered incisal edge design.
  
  
  CONCLUSIONS
  The butt joint is the type of preparation that least affects the strength of the tooth and the chamfer preparation type is more susceptible to ceramic fractures.
authors.affiliation: Universidade Federal de Mato Grosso do Sul, Campo Grande, Brazil. deisicar@hotmail.com
authors.forename: Deisi Carneiro
authors.initials: DC
authors.lastname: da Costa
authors.forename: Margareth
authors.initials: M
authors.lastname: Coutinho
authors.forename: Albert Schiaveto
authors.initials: AS
authors.lastname: de Sousa
authors.forename: Jussara Peixoto
authors.initials: JP
authors.lastname: Ennes
mesh_terms: D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003801:Dental Veneers; D006801:Humans; D013314:Stress, Mechanical; D013499:Surface Properties; D019228:Tooth Crown / Q000293:injuries; D014082:Tooth Fractures / Q000503:physiopathology*; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*; D014092:Tooth Root / Q000293:injuries
chemical_list: D003776:Dental Porcelain