Influence of different etching protocols on the reliability of resin bonding to CAD/CAM feldspathic porcelain

The application of HF to etch the CAD/CAM feldspathic porcelain surface reduced the microhardness number. Etching with 5% hydrofluoric acid on dental porcelain for more than 1 min might impair the reliability of resin bonded porcelain veneer.