Influence of Surface Pretreatment Using Cold-active Atmospheric Pressure Plasma on Bond Strength of CAD-CAM-fabricated Hybrid Ceramic Crowns: an In-vitro Study

Purpose: This study assesses the impact of Cold Atmospheric Pressure Plasma (CAP) pretreatment on the bond strength of two-piece hybrid ceramic abutment crowns in implant dentistry. The objective is to ascertain whether CAP can be employed as an alternative or complementary technique to conventional methods.

Methods: 80 titanium bases and 80 VITA ENAMIC polymer-infiltrated ceramic network (PICN) crowns were divided into 8 groups (n = 10) based on different surface pretreatments of the crowns before cementation: no treatment (A), hydrofluoric acid (HF) (B), HF and silane (C), silane (D), CAP (AP), HF and CAP (BP), HF, CAP, and silane (CP), and CAP and silane (DP). Bond strength (BS) was measured after thermocycling (5000 cycles at 5 °C/55 °C), and statistical analysis was performed using three-way ANOVA.

Results: The highest bond strength (BS) was recorded in the conventionally pretreated group C. Both HF and silane alone had significant effects (p < 0.0001), but CAP alone did not (p = 0.9377). Significant interactions were found between silane and CAP (p = 0.0222), and HF and CAP (p = 0.0046). The combined effects exceeded individual effects. Although group C showed the highest BS, no significant interaction was found between HF and silane (p = 0.6270). Three-factor interactions were significant (p < 0.0001).

Conclusion: In the setting used, CAP could not replace conventional pretreatment. The highest BS of a group without HF was achieved by combining silane with CAP. However, BS of this pretreatment was approximately 24% lower than that of the conventional pretreatment.