Single tooth crowns supported on hydroxyapatite coated endosseous dental implants: a prospective 5-year study on twenty subjects.

Aim: To evaluate the success and maintenance requirements of cylindrical, hydroxyapatite coated implants used as single-tooth implants. Design: A five-year prospective trial. Method: Twenty patients, attending the Department of Prosthetic Dentistry at GKT Dental Institute, London, were provided with 23 Calcitek, Integral Omniloc single tooth implants. Annual reviews were undertaken for five years. Assessment criteria included implant survival; abutment or crown looseness; radiographic evidence of bone loss; evidence of plaque and inflammation of the mucosal cuff; the patient's perception of the restoration. Results: All implants integrated. Two subjects, with three crowns, dropped out giving a known cumulative survival rate of 87%. Twelve implants exhibited no measurable bone loss and six demonstrated funnel formation up to 2mm in depth which, at five years, appeared to be stable; three implants exhibited continuing bone loss and their inclusion as failures gives a known success rate of 74%. The abutments came loose on four occasions; the crowns decemented on 12 occasions; two crowns were repaired and one remade. The appearance was judged to be good or very good. Conclusion: The prospective study indicated that hydroxyapatite coated implants can be successful as single tooth implants, over a five-year period.