title: Bond strength of universal adhesives: A systematic review and meta-analysis.
abstract: OBJECTIVE
  A systematic review was conducted to determine whether the etch-and-rinse or self-etching mode is the best protocol for dentin and enamel adhesion by universal adhesives.
  
  
  METHODS
  This report followed the PRISMA Statement. A total of 10 articles were included in the meta-analysis.
  
  
  METHODS
  Two reviewers performed a literature search up to October 2014 in eight databases: PubMed, Web of Science, Scopus, BBO, SciELO, LILACS, IBECS and The Cochrane Library.
  
  
  METHODS
  In vitro studies evaluating the bond strength of universal adhesives to dentin and/or enamel by the etch-and-rinse and self-etch strategies were eligible to be selected. Statistical analyses were conducted using RevMan 5.1 (The Cochrane Collaboration, Copenhagen, Denmark). A global comparison was performed with random-effects models at a significance level of p<0.05.
  
  
  RESULTS
  The analysis of dentin micro-tensile bond strength showed no statistically significant difference between the etch-and-rinse and self-etch strategies for mild universal adhesives (p≥0.05). However, for the ultra-mild All-Bond Universal adhesive, the etch-and-rinse strategy was significantly different than the self-etch mode in terms of dentin micro-tensile bond strength, as well as in the global analysis of enamel micro-tensile and micro-shear bond strength (p≤0.05).
  
  
  CONCLUSIONS
  The enamel bond strength of universal adhesives is improved with prior phosphoric acid etching. However, this effect was not evident for dentin with the use of mild universal adhesives with the etch-and-rinse strategy.
  
  
  CONCLUSIONS
  Selective enamel etching prior to the application of a mild universal adhesive is an advisable strategy for optimizing bonding.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil. Electronic address: wellington.xy@gmail.com.
authors.forename: Wellington Luiz de Oliveira da
authors.initials: WL
authors.lastname: Rosa
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil. Electronic address: evpiva@gmail.com.
authors.forename: Evandro
authors.initials: E
authors.lastname: Piva
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil. Electronic address: adriana@ufpel.edu.br.
authors.forename: Adriana Fernandes da
authors.initials: AF
authors.lastname: Silva
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D003804:Dentin; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C498353:G-Bond; D008689:Methacrylates; D019279:Resin Cements
keywords: Adhesives; Dental bonding; Dental materials; Systematic review