Objective: To evaluate the effects of cold atmospheric plasma (CAP) on adhesive bonding in Class II composite restorations in vitro. Methods: Forty-eight standardized Class II cavities were assigned to six groups (n = 8), varying in phosphoric acid conditioning, CAP treatment (1.5 W or 3 W), composite filling, and thermo-mechanical loading (TML). Evaluations included dye penetration, adhesive layer morphology, resin tag length, and hybrid layer thickness. Results: CAP combined with phosphoric acid (H3PO4) significantly increased hybrid layer thickness and resin tag length (p < 0.006). The lowest dye penetration was observed in Groups 1 and 4. Conclusions: CAP in combination with phosphoric acid improved the adhesive interface in Class II cavities. CAP alone showed limited benefits, and higher power levels may negatively affect bonding.
Gund et al. (Thu,) studied this question.