Effect of Surface Treatments on the Repair of a Hybrid Ceramic through the Microtensile Test

This study evaluated the microtensile bond strength between a hybrid ceramic and a composite resin under different surface treatments and aging. Hybrid ceramic blocks were divided into five groups based on surface treatment and thermocycling: HF: 5% hydrofluoric acid; HFS: hydrofluoric acid and silane; A110S: sandblasting with aluminum oxide and silicatization; A50: aluminum oxide particle blasting; R: roughening. All samples were cemented to composite resin. After 24-hour storage in distilled water at 37ºC, the blocks were cut into sticks and tested immediately or after 10,000 cycles. Microtensile bond strength was tested using a universal testing machine. Failure modes were visualized and classified as cohesive, adhesive, and predominantly adhesive. Statistical differences were found between groups for surface treatment and thermocycling (p<0.05). Hybrid ceramics showed higher bond strength when etched with hydrofluoric acid and silanized, but bond strength decreased after thermocycling in all groups.