[Clinical study of application of platform switching to dental implant treatment in esthetic zone].

Objective: To evaluate the clinical results of dental implant treatment with platform switching technique in esthetic zone and to investigate its technical characteristics.

Methods: Seventeen patients who were partially edentulous in esthetic zone were included and received a total of 26 Frialit-2 system implants in Center of Dental Implantation, Peking University School and Hospital of Stomatology from January to December 2001, and the platform switching technique was applied. The mean follow-up time was 56.3 months (24 to 74 months). Clinical examination and X-ray were conducted.

Results: Clinical results of all implant restoration that used platform-switched abutments were satisfied. No implant loss or other severe complications occurred. The medians of marginal bone loss 1 year and 5 years after final restoration was 0.13 (-0.12 - 0.55) mm and 0.27 (-0.04 - 0.77) mm respectively. The medians of interimplant crestal bone resorption was 0.14 (0.00 - 0.30) mm and 0.21 (0.09 - 0.31) mm after 1 year and 5 years' functional loading respectively. According to Jemt classification of papilla, 23 sites reached II degree, and 10 sites reached III degree among 36 sites 5 years after prostheses. The mean value of pink esthetic score (PES) was 11.8 (10 - 14).

Conclusions: Platform switching is a simple and reliable technique for dental implant treatment, helping to control marginal bone loss and ensure an esthetic results in the esthetic zone.