Optimizing resin bonding to saliva-contaminated polyetheretherketone: comparative efficacy of cleaning methods

This study investigated the effects of saliva contamination and different cleaning protocols on the surface characteristics and bonding performance of polyetheretherketone (PEEK). A total of 120 PEEK specimens were divided into six groups: uncontaminated (UN), contaminated without cleaning (S), and contaminated followed by cleaning with Ivoclean (IC), Katana Cleaner (KC), ethanol (ALC), or sandblasting (BLA). Resin composite cylinders were bonded to the specimens, and shear bond strength (SBS) was evaluated before and after 10,000 thermal cycles. Surface properties (water contact angle, roughness) were analyzed. Saliva contamination significantly reduced SBS (P < 0.05), irrespective of aging. The IC and ALC groups showed significantly lower SBS than the UN group. In contrast, cleaning with KC or BLA effectively restored SBS to levels comparable with uncontaminated PEEK, under both aged and unaged conditions. Adhesive failure was the predominant failure mode. While contamination and cleaning reduced hydrophobicity (lower contact angles), surface roughness remained unchanged across groups. Salivary contamination impairs PEEK-resin bonding, but sandblasting or Katana Cleaner effectively restores bond strength. These protocols offer clinically viable decontamination strategies for PEEK-based restorations.