Cover Screw vs Healing Abutment on Osseointegration

This prospective randomized split-mouth controlled clinical trial evaluates the effects of cover screw placement and healing abutment placement on early implant stability and osseointegration. Systemically healthy patients requiring at least two dental implants will be enrolled. Using a split-mouth design, each participant will receive both interventions, with one implant randomly allocated to receive a cover screw (two-stage protocol) and the contralateral implant to receive a healing abutment (one-stage protocol).

Implant stability will be evaluated by insertion torque and resonance frequency analysis (RFA). Implant Stability Quotient (ISQ) values will be recorded at implant placement and at the 3-month follow-up. The primary objective is to compare changes in implant stability (ΔISQ) between the two treatment protocols. Secondary outcomes include implant survival, peri-implant soft tissue healing, and postoperative complications.

Inclusion criteria

• Adults aged ≥18 years. American Society of Anesthesiologists (ASA) physical status I or II. Able and willing to comply with the study protocol and follow-up schedule. Required at least two dental implants in contralateral or symmetrical edentulous sites.

Implant sites free of active infection or acute periodontal disease. Adequate oral hygiene. Sufficient bone volume for placement of a standard-diameter implant with at least 1.5 mm of surrounding peri-implant bone.

Keratinized mucosal width ≥2 mm. Soft tissue thickness ≥2 mm. Written informed consent provided.

Exclusion criteria

• Systemic diseases or medical conditions contraindicating implant surgery. Uncontrolled diabetes mellitus (HbA1c >10%). Current intravenous antiresorptive therapy. History of head and neck radiotherapy. Immunosuppressive therapy. Active malignancy. Uncontrolled hypertension. Advanced hepatic or renal insufficiency. Pregnancy. Poor oral hygiene. Active oral infection. Requirement for bone augmentation before implant placement. Inadequate bone volume. Unfavorable peri-implant soft tissue phenotype. Primary implant stability <20 Ncm at implant placement.