Influence of Crown-to-Implant Ratio on Crestal Bone Loss at Implants with Single Crowns and Bridges: A 5- to 20-Year Long-Term Cohort Study in Patients with Periodontal Disease.

Purpose: To evaluate how the crown-to-implant (C/I) ratio affects the loss of crestal bone at single-crown implants and bridges in patients with periodontal disease.

Materials And Methods: A total of 39 patients treated for periodontitis were rehabilitated with 108 implant-supported single crowns and bridges. Each patient was examined over a 5- to 20-year period on a 3- to 6-month recall schedule.