A patient reports that a single implant-supported crown feels loose. Radiographs show approximately 3 mm of bone loss over the first year, with no bleeding, suppuration or signs of inflammation. What is the MOST appropriate management?

Correct answer: C. Replace the abutment screw and re-seat the existing crown

• A. Explantation is not indicated. The implant is osseointegrated; the mobility is prosthetic, and there is no evidence of peri-implantitis.
• B. Replacing the crown while retaining the compromised screw addresses the wrong component entirely — the screw is the failed element.
• C. CORRECT. The absence of inflammation, bleeding and suppuration points to a MECHANICAL rather than a biological complication — abutment SCREW LOOSENING, which is the most common prosthetic complication of single implant crowns. The established protocol is to retrieve the restoration, discard the loosened screw and place a NEW one (a screw that has loosened has undergone permanent deformation and loss of preload, so it is never re-torqued), then re-seat and re-torque the intact crown to the manufacturer's specification. The crown itself is undamaged and is reused.
• D. Replacing the crown as well is unnecessary and wasteful when the restoration is intact and correctly contoured. Only the screw has failed.

Note: ⚠️ Note on the bone loss: 3 mm in the first year EXCEEDS the accepted threshold (roughly 1.5 mm in year one, then ≤0.2 mm annually). Investigate the cause — occlusal overload, excess cement, or the very screw loosening described. Correct the screw, verify occlusion, exclude residual cement, and place the patient on close radiographic review.