Alternative surface treatments strategies for bonding to CAD/CAM resin-matrix ceramics

Abstract

This study evaluated the shear bond strength (µSBS) and failure mode of CAD/CAM polymer-infiltrated ceramic network (PICN – Vita Enamic) and nanoceramic resin (NCR – Lava Ultimate) submitted to alternative surface treatments. 40 plates of each material were submitted to (n = 10) conventional (manufacturer’s indications): Sandblasting with Al₂O₃ (SAND) and 5% hydrofluoric acid etching (5% HF), or alternative treatments: 10% HF (10% HF) and Sandblasting + silanization (SAND/SIL). A self-etching adhesive system (Scotchbond Universal Adhesive, 3M Oral Care) was applied, and resin cement cylinders were built on the specimen’s treated surface and tested in µSBS after 24 h, or after water storage for 1 year. Data were evaluated by three-way repeated-measures ANOVA and Tukey test (α = 0.05). Failure mode was evaluated under scanning electron microscopy (SEM). At 24 h, HF etching (5% or 10%) promoted higher µSBS for PICN, while SAND and 5% HF promoted higher µSBS for NCR than SAND/SIL (p > 0.05). After storage for 1 year, all treatments decreased PICN’s bond strength, but 10% HF exhibited higher µSBS than 5% HF (p < 0.05). Also, 5% HF and SAND/SIL maintained µSBS of NCR, and in general, NCR exhibited higher µSBS than PICN. Failure mode was predominantly mixed after 24 h and mostly adhesive after 1-year storage. In conclusion, the surface treatments influenced the bond strength of PICN and NCR and 1-year storage decreased the bond strength for most groups. 10% HF is the treatment option for PICN while 5% HF-etching is an alternative to sandblasting for NCR.

Keywords:

• Adhesives
• CAD-CAM
• hydrofluoric acid
• polymers

Acknowledgments

The authors acknowledge the valuable contribution of Dr. Elliot Watanabe Kitajima and Renato Barbosa Salaroli, from the College of Agriculture ‘Luiz de Queiroz’ (University of São Paulo, Piracicaba, SP, Brazil) for their assistance in microscopy analyses. The authors acknowledge the support of 3M Oral Care for donating the materials tested.

Disclosure statement

C. M. Wanderico has received a research grant from the National Council for Scientific and Technological Development as part of the scientific initiation program as an undergraduate student (PIBIC/CNPq).

Additional information

Funding

This research was supported by the National Council for Scientific and Technological Development as part of the scholarship program for scientific initiation (PIBIC/CNPq – Scholarship of Scientific Initiation). This study was financed in part by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.