Implants · patient case question
What does routine maintenance of a screw-retained implant prosthesis require?
Patient case: Maintenance of a screw-retained implant prosthesis
Patient: Male, 59 years old
Chief Complaint: Attends for review of a screw-retained implant-supported prosthesis placed eighteen months ago.
Background: Non-smoker. Well-controlled hypertension. Good plaque control.
Current Findings: The prosthesis is stable and the peri-implant tissues are healthy, with no bleeding on probing and no radiographic bone loss beyond expected remodelling. He asks what ongoing care the restoration will need.
Show answer and explanation
Correct answer: C. Periodic assessment and retightening of the abutment screws to the specified torque
- A. A screw-retained prosthesis is fixed and is removed only by the clinician. Patient removal describes an overdenture.
- B. There is no fixed replacement interval. Implant prostheses are replaced when they fail or when the biology demands it, not on a calendar.
- C. Screw joints undergo settling and preload loss over time. Screw loosening is the commonest mechanical complication of screw-retained restorations, and an undetected loose screw permits micromovement, which leads to screw fracture and to bacterial colonisation of the implant-abutment interface. Periodic assessment and retorquing to the manufacturer's specification is standard maintenance.
- D. Implant prostheses require MORE maintenance than natural teeth, not less — professional peri-implant assessment, radiographic monitoring and mechanical review.
Note: The retrievability of screw retention is precisely its advantage: no excess cement to leave subgingivally, and the prosthesis can be removed for repair. Its trade-offs are the access hole and greater sensitivity to angulation.