The goal of this clinical trial is to evaluate the effect of abutment surface bioactivation via argon plasma treatment on peri-implant soft tissue healing and integration in adult patients undergoing implant therapy.

The main questions it aims to answer are:

Does argon plasma treatment of healing abutments improve the quality and organization of peri-implant connective tissue compared to untreated abutments?

Does the treatment influence histological parameters such as epithelial regeneration, vascularization, inflammatory infiltrate, and keratin layer thickness?

Researchers will compare plasma-treated healing abutments to untreated machined-surface abutments to determine whether the bioactivated surface improves soft tissue morphogenesis.

Participants will:

Undergo implant placement with immediate connection of either a treated or untreated healing abutment.

Have plaque and bleeding indices recorded at 3 months.

Undergo a soft tissue biopsy at 3 months for histological analysis (including evaluation of inflammation, connective tissue, epithelial morphology, vascularization, and keratinization).

Inclusion Criteria:

• presence of at least 4 mm of keratinized mucosa around the implants
• patients aged 18 years or older
• medically healthy patients (ASA I), or patients with mild systemic disease (ASA II)
• partially edentulous state
• healthy periodontal condition (also including periodontal health on reduced periodontium) according to the referent case definition

Exclusion Criteria:

• ASA physical status 3
• severe smokers (> 10 cig/day)
• patients undergoing bisphosphonate therapy
• pregnant or lactating women
• estrogen-related hormonal disorders or hormonal substitution therapy
• untreated periodontitis (pocket depth 4mm with positive bleeding on probing)
• multiple gingival recession
• patients with a history of head and neck cancers and radiotherapy in this region.