Cleansability of zirconia implants after exposure to different contamination media: a methodological assessment

This study evaluated the effects of different cleansing protocols on the wettability, surface free energy, and chemical composition of zirconia surfaces contaminated with saliva or metallic particles. Zirconia specimens (N = 90) were randomly assigned to three contamination conditions (none, saliva, metallic particles) and six cleansing protocols (C-control, A-autoclave, U-ultrasonic bath, E-ethanol, C-chlorhexidine, H₂O₂-hydrogen peroxide). Surface wettability was assessed by contact angle measurements with water and diiodomethane, and work of adhesion (WoA) and surface free energy (SFE) were calculated using the Owens-Wendt-Rabel-Kaelble model. Elemental composition was analyzed using energy-dispersive X-ray spectroscopy (EDS). Data were analyzed with two-way ANOVA and Tukey's post hoc test (α = 0.05). Both contamination type and cleaning method significantly influenced contact angle, WoA, and SFE (p < 0.001), including their interaction. Saliva and metallic contamination decreased surface hydrophilicity and polar SFE. Chlorhexidine was most effective, restoring low contact angles and high SFE across all conditions. Ethanol and autoclave also performed well, especially in saliva-contaminated samples. Ultrasonic cleaning effectively removed metallic debris. Hydrogen peroxide results were inconsistent, notably after metallic contamination. Contamination alters zirconia surfaces; cleaning effectiveness varies with contaminant type and protocol. Chlorhexidine is the best cleaner. Ethanol, autoclave, and ultrasonic methods are alternatives, with ultrasonic especially effective against metals because of its mechanical cleaning. Effective zirconia implant cleaning is vital to restore wettability after contamination. Findings show hydrogen peroxide alone may be inadequate, highlighting the need for more reliable cleaning methods.