One-minute application etches porcelain crowns, veneers, inlays and fractured porcelain surfaces prior to bonding. This superior quality porcelain etch gel will not stain porcelain, composites or resin cements. Porcelain Etch Gel, 9.6% hydrofluoric acid, 4 - 1.2 ml syringes and 8 pre-bent needles.