Impact of Root Surface Conditioning With Erythritol Air Polishing and Hand Instrumentation on Recession Coverage Using the Modified Tunnel Technique and Subepithelial Connective Tissue Graft.

Inclusion Criteria: * Multiple RT1 and/or RT2 gingival recessions, symmetrical and bilateral, with a minimum height of ≥ 1 mm * Full-mouth plaque score (FMPS) \< 15% (assessed on four surfaces per tooth) * Full-mouth bleeding on probing (FMBOP) \< 15% (assessed on four surfaces per tooth) * Detectable cemento-enamel junction (CEJ) * Age ≥ 18 years Exclusion Criteria: * RT3 gingival recessions * Gingival recessions affecting second and third molars * Systemic or infectious diseases that may impair wound healing, including active malignancy, diabetes mellitus with HbA1c \> 7.0%, history of head and neck radiotherapy, true xerostomia, and HIV/AIDS * Cervical caries, non-carious cervical lesions, or Class V restorations interfering with the CEJ * Active periodontitis * Use of medications affecting periodontal tissues or wound healing, including systemic corticosteroids, immunosuppressants, isotretinoin, bisphosphonates, and monoclonal antibodies with immunosuppressive, antiresorptive, or antiangiogenic effects * Smoking * Pregnancy or breastfeeding