AIM: To evaluate the bond strength of brackets bonded after different surface treatments on two dental ceramics. METHODS: One hundred and twenty discs 5 mm thick and 7 mm diameter of two ceramic types were made and randomly divided in 8 groups. Groups 1, 3, 5, and 7 used Eris ceramic and groups 2, 4, 6, and 8 used d.Sign ceramic. The ceramic surfaces were treated with 10% hydrofluoric acid G1 and G2, 10% hydrofluoric acid + silane G3 and G4, aluminum oxide blasting + 35% phosphoric acid + silane G5 and G6, CoJet blasting + 35% phosphoric acid + silane G7 and G8. Metallic brackets were cemented with Concise cement. Mechanical test was performed in a universal testing machine until failure. RESULTS: The average values MPa obtained G1 - 7.30; G2 - 6.12; G3 - 17.49; G4 - 19.54; G5 - 18.80; G6 - 21.93; G7 - 6.81 e G8 - 9.77 were submitted to ANOVA and Tukey test p<0.05. The fracture patterns were analyzed in stereoscopic microscope 25´X and representative samples of each group were analyzed in SEM. CONCLUSIONS: It was possible to conclude that use of silane after hydrofluoric acid increased the bond strength values.

The purpose of this study was to evaluate the influence of buccal and lingual wall thickness on the fatigue resistance of molars restored with CAD/CAM ceramic inlays. Forty human third molars were selected and divided into 4 groups, according to the remaining surrounding wall thickness chosen for inlay preparation (n = 10): G1, 2.0 mm; G2, 1.5 mm; G3, 1.0 mm; G4, 0.5 mm. All inlays were made from feldspathic ceramic blocks by a CAD/CAM system, and cemented adhesively. After 1 week stored in distilled water at 37 °C, the specimens were subjected to fatigue testing under the following protocol: 5Hz; pre-load of 200 N for 5,000 cycles, followed by increasing loads of 400, 600, 800, 1000, 1200 and 1400 N for 30,000 cycles each. The specimens were cycled until failure or completion of 185,000 cycles. The survival rate of the groups was compared using the Kaplan-Meier survival curves (p > 0.05). All specimens withstood the fatigue protocol (185,000 cycles), representing a 100% survival rate. The Kaplan-Meier survival curves showed no difference between groups. It can be concluded that the remaining tooth wall thickness did not influence the fatigue resistance of molars restored with CAD/CAM ceramic inlays.