title: Evaluation of bond strength of different adhesive systems: Shear and Microtensile Bond Strength Test.
abstract: OBJECTIVE
  Aim of this work is the in vitro bond strength evaluation of three bonding agents comparing the results of two kinds of test, Microtensile Bond Strength Test and a Shear Bond Strength Test. Bond strength tests have been used to test both direct and indirect restorative techniques to investigate if methods could give different results.
  
  
  METHODS
  72 human third molars have been collected and stored in physiological solution. Three kinds of test were conducted: 1- SB, 2- "Slice" preparation μTBS1, 3- "Stick" preparation μTBS2. We tested three different adhesive systems (Groups 1-2-3 n=24), two restorative techniques (subgroup A-B n=12). The tested adhesives were: Optibond FL (OFL) (Group 1), Optibond Solo Plus (OSP) (Group 2), Optibond Solo Plus Self-Etch (OSSE) (Group 3). For all tests was used a universal load machine Instron Machine.
  
  
  RESULTS
  Best values were found for Optibond FL with mean values of 45-50 MPa. Optibond Solo Plus resulted in values very similar and in some cases almost identical to FL. Optibond Solo Self Etch showed poorer adhesion in both direct and indirect restorative techniques. The parametric and non parametric statistical variance analysis pointed out the absence of significant differences between OFL and OSP, and demonstrated a significant difference for OSSE adhesive.
  
  
  CONCLUSIONS
  The results confirm that a total etch two-step adhesive is the best compromise between easiness and effectiveness.
authors.affiliation: University of Rome "Tor Vergata", Department of Dental Science, Operative Dentistry, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Gallusi
authors.forename: P
authors.initials: P
authors.lastname: Galeano
authors.forename: A
authors.initials: A
authors.lastname: Libonati
authors.forename: M R
authors.initials: MR
authors.lastname: Giuca
authors.forename: V
authors.initials: V
authors.lastname: Campanella
keywords: Microtensile Bond Strength Test; Shear Bond Strength Test; dentin-bonding agents; direct restorations; indirect restorations