What is the MINIMUM interocclusal (restorative) space required, measured from the implant platform to the opposing arch, for an implant-level SCREW-RETAINED restoration?

Correct answer: B. 5 mm

• A. Incorrect. 7–8 mm is the cement-retained range; screw retention needs considerably less.
• B. Correct. Approximately 4–5 mm of vertical restorative space is the accepted minimum for an implant-level screw-retained restoration — this accommodates the prosthetic screw, the connection interface and an adequate thickness of restorative material. Screw retention is therefore the design of choice when interocclusal space is limited.
• C. Incorrect. 9 mm exceeds what is needed for any single-unit fixed implant restoration. (For reference, a bar overdenture needs roughly 11 mm and a full-arch screw-retained hybrid around 15 mm.)
• D. Incorrect. About 7 mm is the requirement for a CEMENT-RETAINED restoration, which must additionally accommodate soft-tissue height plus a 4–5 mm abutment for retention form.

Note: Hierarchy worth memorising: screw-retained implant-level 4–5 mm < unsplinted overdenture ≈ 7 mm ≈ cement-retained 7–8 mm < bar overdenture ≈ 11 mm < fixed hybrid ≈ 15 mm.