This research evaluated the shear bond strength of metallic brackets bonded to bovine teeth, using conventional adhesive system consisting of phosphoric acid + primer + adhesive resin, and a system SEP (self-etching primer) that combines acid and primer in one solution. The SEP system was evaluated in either dry and moist (water) environments. Forty-eight lower bovine incisors teeth were divided in three groups of sixteen units each one, prepared as following: group 1(control) phosphoric acid 37% + primer + Transbond XT resin; group 2 Transbond Plus Self Etching Primer in dry environment + Transbond XT resin, and group 3 the Transbond Plus Self Etching Primer applied in moist environment + Transbond XT.After bonding, the mechanical test was performed with an Instron machine (crosshead speed of 1mm/min). The shear bond strength were: 9,29 MPa for group 1;10,57 MPa for group 2 and 7,45 MPa for group 3.All groups showed clinical acceptable resistance. There wasn't significant difference between conventional system and the SEP in dry environment, neither in moist environment. However, there was a significant reduction in the shear bond strength for the SEP in moist environment when compared with SEP in dry environment. It was concluded that Transbond + Self Etching Primer showed shear bond strength to enamel similar to phosphoric acid 37% + primer, therefore it is indicated to clinically bond orthodontic brackets.
Enamel bond; Dentin adhesive; Orthodontic brackets; Self-etching primer
