Effect of hydrofluoric acid concentration and etching time on resin-bond strength to different glass ceramics

In conclusion, etching with 5% HF for 20 seconds is recommended for lithium disilicate and leucite-reinforced CAD/CAM ceramics. However, for pressed lithium disilicate ceram ic, 10% HF for 60 s showed significantly higher bond strength to resin cement.
Source: Brazilian Oral Research - Category: Dentistry Source Type: research