Effectiveness of Cleaning Agents on Bond Strength to Contaminated Zirconia

Evaluate the effect of several cleaning methods on resin bond to contaminated zirconia before and after thermocycling.

One hundred zirconia specimens (KATANA STML, Noritake) were prepared and randomly divided into four experimental and one control group (n = 20). Specimens were contaminated with human saliva and cleaned using different methods: air-particle abrasion (APC), Katana Cleaner (KC), Ivoclean (IC), and Zirclean (ZC). Cylindrical composite resin specimens (2.1 mm diameter, 3 mm height) were bonded using dual-cure composite resin cement (Panavia V5, Kuraray Noritake). After 48 h of storage in distilled water at 37°C, half the specimens underwent 10,000 thermal cycles. Shear bond strength (SBS) was measured using a universal testing machine (Instron, Grove City, PA) at 0.5 mm/min. Fractured surfaces were examined under a stereomicroscope for failure type (adhesive, cohesive, or mixed). Statistical analysis included one-way ANOVA and post hoc Bonferroni test (α = 0.05).

Significant differences in SBS were found between normal and thermocycling conditions in all groups (p < 0.05). APC showed significantly higher SBS than other cleaning methods (p < 0.05).

While air-particle abrasion showed the highest effectiveness, chemical cleaners offered viable alternatives. Thermocycling reduced bond strength across all groups.