• Used for etching various types of resin bonded porcelain/ceramic restorations (conventional feldspathic porcelain, leucite glass ceramic, lithium disilicate, zirconia reinforced lithium silicate glass-ceramic, fluorapatite glass ceramic, etc.) before the bonding and cementation procedure.
• It makes the restoration surface rougher and enhances mechanical interlocking force.
Notes: Hydrofluoric acid in HF-Etchant can be selectively combined with silicon in silicate ceramics to form tetrahedral water-soluble SiF4 compounds, which can form cellular mechanical retention structures on ceramic surfaces after water washing.
Hydrofluoric acid is highly toxic and lethal when combines with Calcium ions in the human body. So HF acid usually is used for pretreatment of restorations outside the mouth and requires to be washed off or neutralized by alkaline.