Implants · patient case question
What is the minimum mesiodistal space required to place an implant between two natural teeth?
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: A. 7 mm
- A. CORRECT. A standard-diameter implant of about 4 mm requires at least 1.5 mm of bone between the implant surface and each adjacent root, giving 4 + 1.5 + 1.5 = 7 mm as the minimum mesiodistal dimension. Less than that risks damaging adjacent roots and compromising the interproximal bone that supports the papilla.
- B. 5 mm leaves under 1 mm on either side of a standard implant — insufficient bone and a high risk of damage to the adjacent roots.
- C. 12 mm would accommodate a wide implant or even two implants; it is far more than the minimum requirement.
- D. 9 mm is comfortable but exceeds the minimum, and the question asks for the minimum.
Note: The related numbers worth carrying: 1.5 mm minimum from implant to adjacent TOOTH, and 3 mm minimum between two adjacent IMPLANTS.