Clinical and Radiographic Comparison between Platform-Shifted and Nonplatform-Shifted Implant: A One-Year Prospective Study.

Abstract

Developments in implant hardware and biologic understanding improved treatment predictability in terms of implant survival. Current research focuses on accelerated loading protocols and crestal bone preservation. This prospective, monocenter study analyzed the clinical and radiographic outcome of a novel parallel-walled implant, with and without platform shift. Forty-eight consecutively treated patients (30 women, 18 men) with crowns/bridges supported by 115 implants were included. Eighty-three percent of implants were nonocclusal, immediately loaded, and 17% were subjected to one-stage surgery and delayed loading after 10 weeks; 39.1% were of diameter 5.0 mm, enabling platform shifting with a 4.0 mm-wide prosthetic component; 60.9% were of diameter 4.0 mm with a 4.0 mm component. Radiographic crestal bone levels were assessed at baseline and 1 year. A multivariate statistical analysis was performed to determine factors affecting crestal bone loss after 1 year. All implants survived and mean marginal bone loss was 0.73 mm (SD: 0.13; range: -0.60 to 5.0 mm). There was a statistically significant difference between platform-shifted (0.63 mm; SD: 0.18) and nonplatform-shifted (1.02 mm; SD: 0.14) implants. Implants in abundant bone volume lost significant less crestal bone (0.45 mm; SD: 0.14) compared with implants in small volume (1.20 mm; SD: 0.21). Implant diameter, loading time, anatomical position, smoking, and bone quality did not affect crestal bone loss. After 1 year of loading, both implant-prosthetic features yield a high survival and limited crestal bone loss. Crestal bone loss is minimized using platform-shifted implants placed in sufficiently voluminous bone. To limit the crestal bone loss, an adopted implant diameter with platform shifting should be considered.