Influência do tempo de condicionamento e concentração do ácido fluorídrico na resistência de união de um sistema adesivo à superfície de cerâmicas para CAD/CAM

Abstract

Aims: to evaluate the microtensile bond strength of an adhesive (Signum Ceramic Bond (Heraeus / Kulzer) made for repairing fractured CAD/CAM ceramics after different surface treatments. Materials and Methods: Three different types of ceramic blocks for CAD / CAM were used: Mark II, Empress CAD and e.max CAD. The ceramics were divided into four subgroups according to the following surface treatment: G1: roughening with specific drill (ASP, Signum) + adhesive system; G2: hydrofluoric acid (HF) 5% + Signum, G3: ASP + 5% + AF Signum, G4: ASP + AF 10% + Signum. After the adhesive system application, a 6.0 mm resin composite block (Charisma) was made for the microtensile test. After 15 days of storage in distilled water, the blocks were cut and selected 20 sticks with cross sectional area of 1.0 mm2. The specimens were submitted to microtensile in a universal testing machine. Results: The use of ASP + AF 10% promoted the highest bond strength values in the ceramic Mark II (23.08 MPa) and Empress CAD (29.36 MPa). In e.max CAD, the use of ASP + AF 5% led to the highest values of bond strength (25.19 MPa). Based on these results we conclude that the adhesion of the adhesive system Signum for ceramics repairing depends on surface treatment being the association abrasion + hydrofluoric acid the most suitable.