title: Adhesion testing with the microtensile method: effects of dental substrate and adhesive system on bond strength measurements.
abstract: OBJECTIVE
  To evaluate the bond strength of a self-etching primer (SE, Clearfil SE Bond) and a one-bottle adhesive system (EX, Excite) on enamel and dentin.
  
  
  METHODS
  Twenty-eight sound human molars were used. The teeth were randomly divided into four groups (n = 7): SE applied to enamel (SE-E); SE applied to dentin (SE-D); EX applied to enamel (EX-E); EX applied to dentin (EX-D). A resin (Tetric Ceram) block of approximately 5 x 5 x 5 mm was built up on the tooth and cured for 40 s. After 24 h, samples were obtained by cutting along the x and y axis of the tooth. Stick-shaped samples of approximately 0.8 mm2 cross-sectional area were obtained. The sticks underwent microtensile testing.
  
  
  RESULTS
  The tensile bond strength (MPa) values of the test groups were: SE-E, 38.9 (+/- 4.8); SE-D, 44.5 (+/- 7.7); EX-E, 45.8 (+/- 4.7); EX-D, 42.9 (+/- 7.1). These values were not statistically significantly different.
  
  
  CONCLUSIONS
  The null hypothesis was accepted that there is no difference between the self-etching primer and the one-bottle adhesive tested here. In addition, the bonding conditions provided by either bonding material on enamel were not significantly more favorable than on dentin. The majority of the specimens failed adhesively under load.
authors.affiliation: Department of Dental Materials, Faculty of Dentistry, University of São Paulo, São Paulo, Brazil. paulocapel@uol.com.br
authors.forename: Paulo Eduardo Capel
authors.initials: PE
authors.lastname: Cardoso
authors.forename: Fernanda Tranchesi
authors.initials: FT
authors.lastname: Sadek
authors.forename: Cecilia
authors.initials: C
authors.lastname: Goracci
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
mesh_terms: D000268:Adhesiveness; D000269:Adhesives; D000704:Analysis of Variance; D001840:Dental Bonding; D003743:Dental Enamel; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing / Q000379:methods; D008689:Methacrylates; D008963:Molar; D011897:Random Allocation; D019279:Resin Cements; D018709:Statistics, Nonparametric; D013718:Tensile Strength
chemical_list: D000269:Adhesives; C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; C420130:Excite cement; D008689:Methacrylates; D019279:Resin Cements