Surface Treatments On Saliva-Contaminated Dental Glass-Ceramics

Saliva contamination during intraoral try-in can significantly reduce the bonding performance of lithium disilicate ceramics. This study aimed to evaluate the effectiveness of different decontamination methods in restoring bonding strength. Lithium disilicate ceramic specimens (12 × 10 × 2 mm, *n* = 120) were contaminated with human saliva and treated using five methods: hydrofluoric acid etching, phosphoric acid cleaning, universal cleaning agent, self-etching ceramic primer, and high-temperature firing. Surface composition was assessed using X-ray photoelectron spectroscopy (XPS), and siloxane bond formation was analyzed by Raman and Fourier-transform infrared spectroscopy (FTIR). Shear bond strength (SBS) was measured after water storage at 37 °C for 24 hours and 3 months. Statistical analysis was conducted with SPSS 26.0. High-temperature((500°C)) firing most effectively removed protein residues, as shown by XPS. Raman and FTIR analysis demonstrated the highest siloxane bond formation after high-temperature firing, followed by phosphoric acid, self-etching primer, universal cleaner, and hydrofluoric acid. The control group (uncontaminated) and the high-temperature group showed the highest SBS values (21.77 ± 2.45 MPa and 21.28 ± 1.58 MPa), with similar results after aging. High-temperature firing(500°C) was the most effective method for removing saliva contamination and restoring ceramic bond strength. None of the tested treatments improved bonding beyond the uncontaminated baseline.