Cold plasma-mediated implant surface activation may reverse the biological aging of titanium by enhancing hydrophilicity and cellular response. The aim of this study was to clinically compare the effects of three different cold plasma systems on the stability of dental implants. In this prospective randomized controlled within-patient trial, a total of 44 implants were placed in 11 patients. In each patient, four implants were randomly allocated to one of the following groups: control, vacuum plasma, argon jet plasma, and cold atmospheric plasma. All implants were placed using a single-stage protocol with a minimum insertion torque of 45 Ncm. Implant stability was assessed using resonance frequency analysis (ISQ values) immediately after placement and at 2, 4, and 8 weeks.

Inclusion Criteria:

• Age ≥ 18 years.
• Presence of edentulous areas requiring ≥4 implants for fixed prosthetic rehabilitation.
• Good or moderate oral hygiene.
• Adequate patient compliance to attend all follow-up appointments.
• Willingness to voluntarily participate in the study.

Exclusion Criteria:

• Refusal to participate.
• Need for alveolar ridge augmentation.
• Systemic conditions that may impair healing (e.g., uncontrolled diabetes, immunodeficiency, ongoing chemotherapy or radiotherapy, history of head-and-neck radiotherapy, substance or alcohol abuse).
• Untreated periodontal disease.
• Heavy smoking (>10 cigarettes/day).
• Age < 18 years.