A dentist wants to place an implant in the area of the missing second premolar (#12) between natural teeth #11 and #13. What is the minimum mesio-distal distance required between the adjacent natural teeth for implant placement?

Correct answer: C. 7 mm

• A. 5 mm is too narrow — adequate bone and soft tissue need to be maintained around the implant and adjacent teeth.
• B. 11 mm exceeds the minimum requirement.
• C. Correct. A minimum of 7 mm of mesio-distal space is required between adjacent natural teeth to place a standard implant. This allows for approximately 1.5 mm of bone between the implant and each adjacent tooth root, plus the implant diameter itself (~4 mm).
• D. 9 mm would be ideal but is not the stated MINIMUM.