Hydrofluoric Acid Etching
Also written as: HF etching
A surface-conditioning technique in which hydrofluoric acid is applied to silica-based ceramics to create microporosity and enhance adhesive bonding.
Full Definition
Hydrofluoric acid (HF) etching selectively dissolves the glassy phase of silica-based ceramics—such as feldspathic porcelain and lithium disilicate—producing a microporous surface topography that dramatically increases surface area for micromechanical interlocking with resin luting agents. Concentrations of 4–10% are typically used for 20–90 seconds depending on the ceramic type. The procedure is performed chairside or in the laboratory under strict safety protocols, as HF is highly toxic. Editors should be alert to authors confusing HF etching (for silica-based ceramics) with sandblasting or tribochemical silica coating (used for non-silica ceramics).
Usage
Usage note: Hyphenate 'hydrofluoric acid etching' only when used as a compound modifier before a noun (e.g., 'hydrofluoric-acid-etched surface'). Always clarify concentration and duration in methods sections.
In Context
- "Following hydrofluoric acid etching for 20 seconds, the lithium disilicate inlay was rinsed, dried, and silanised." — Prosthodontics clinical protocol
- "The authors omitted the HF etching step for zirconia specimens, an error that the editor flagged during technical review." — Peer-review report