Effect of etching with low concentration hydrofluoric acid on the bond strength of CAD/CAM resin block

• Published in: Dental Materials Journal Vol. 39; no. 6; pp. 1000 - 1008
• Main Authors: NIIZUMA, Yuiko, KOBAYASHI, Mikihiro, TOYAMA, Toshinari, MANABE, Atsufumi
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society for Dental Materials and Devices 27.11.2020; Japan Science and Technology Agency
• Subjects: Abrasion; Bonding strength; CAD; CAD/CAM; CAD/CAM resin blocks; CAM; Ceramics; Computer aided design; Computer aided manufacturing; Dental Bonding; Dental Porcelain; Dentistry; Etching; Hydrofluoric Acid; Low concentrations; Materials Testing; Microscopy, Electron, Scanning; Resin Cements; Resins; Scanning electron microscopy; Shear bond strength; Spectroscopy; Surface Properties; Surface roughness; Surface treatment; CAD/CAM resin blocks; Shear bond strength; Surface treatment; Hydrofluoric acid
• ISSN: 0287-4547; 1881-1361
• DOI: 10.4012/dmj.2018-398

The effect of etching for 90 s with low concentrations (0.5, 1.0, 2.0, 3.0, 3.5, and 4.0%) of hydrofluoric acid (HF) on the adhesiveness of computer-aided design/computer-aided manufacturing (CAD/CAM) resin blocks [CERASMART (CS), SHOFU BLOCK HC (HC), KATANA AVENCIA Block(KA), and VITA ENAMIC (EN)] was investigated. Energy dispersive spectroscopy revealed that the silicon content of HC, KA, and EN groups remained almost constant with HF etching of ≤4%. HF etching increased the surface roughness of all blocks. The HF concentration resulting in the highest shear bond strength in each group was as follows: CS (2.0%), HC (3.0%), KA (3.5%) and EN (0.5%). Scanning electron microscopy revealed that the bonding interface of etched surfaces differed significantly from that of airborne-particle abrasion surfaces. Thus, low concentration HF etching is effective for surface treatment of CAD/CAM resin blocks. The etching effect and optimum HF concentration differ with the block composition and structure.