Influence of air-abrasion on bonding performance of a self-etching adhesive

Objectives: This study evaluated the influence of oxide aluminum air-abraded cavity preparations on the bond strength of a self-etching system and analyzed the morphology of the adhesive/dental substrate interface. Methods: Microtensile - 16 molars had their crows sectioned obtaining 3 sections: V, medium and L. For enamel preparations it was utilized the V or L, and for dentine the medium section. The sections were divided into 2 groups: G1 enamel (E)/dentine (D)-rotatory instrument and G2 E/D-air-abrasion device, application of self-etching system Tyrian SPE + One Step Plus and insertion of Z250 composite resin. After 24h/37ºC, the specimens were sectioned obtaining rectangular “sticks” and the bond strength was tested (0,5mm/min). Results: Means (MPa): G1E- 21.40 (±5.92); G2E- 25.99 (±7.61); G1D- 22.26 (±4.76) and G2D- 31.31 (±6.67). In the statistical analysis it was observed that there was no difference between the cavity preparations types, as well as between the dental substrates and the interactions. SEM–6 sections of E/D were prepared in the same way decrypted below. The specimens were prepared for SEM and photographed. On air-abraded enamel it was observed the formation of smaller tags and more irregular hybrid layer than on conventional cavity preparation. On the other hand, air-abraded dentine showed the formation of tags similarly to conventional preparation, but with lesser number of lateral branches, more irregular hybrid layer and a thicker adhesive layer. Conclusions: It was concluded that the cavity preparation device influenced the morphology; however the employment of air-abrasion system did not influence the bond strength to dental substrate.