Which statement is incorrect concerning the maintenance of dental implants?
A. Plaque and calculus will form on implants and is more difficult to remove from implants than from natural teeth.
B. The health of the peri-implant tissues is a critical factor in the success of dental implants.
C. It is still necessary to schedule patients with implants for cleanings, exams, and radiographs.
D. Dental implants can last as long as 20 years or more.