Influence of crown-implant ratio on implant success rates and crestal bone levels: a 36-month follow-up prospective study

Objectives The aim of this prospective study was to determine how the crown–implant ratio (C/I ratio) influences crestal bone loss and implant success rates after a 3‐year follow‐up, using implants with a sintered porous surface (SPS). Materials and methods On the basis of preestablished inclusion and exclusion criteria, 151 of a cohort of 160 patients with single or partial edentulism were selected as eligible for the study. The 151 patients were treated consecutively from 2005 to 2007 using 280 SPS implants, which were restored with a single crown or a partial fixed denture. The data collection included both clinical and anatomical C/I ratios; other implant prosthetic factors were also recorded. Implants were divided into three groups according to the C/I ratio. Clinical and radiographic examinations were scheduled over a 36‐month follow‐up of functional loading according to a well‐established protocol generally applied to determine implant success rates and crestal bone levels. Statistical analysis was used to determine any significant differences or correlations (P = 0.05). Results A total of 259 SPS implants in 136 patients were followed up for 36 months. According to the success criteria, the overall implant‐based success rate was 98.1%, and the mean peri‐implant bone loss (PBL) was 0.48 ± 0.29 mm. Statistical analysis revealed significant correlation between implant success rate and C/I ratio (P