Six-Year Performance of Fixed Dental Prostheses – A Massive Data Analysis

Objectives: Aim of this study was to evaluate the six year performance of fixed dental prostheses (FDPs) under practice conditions.
Methods: This retrospective study based on claims data from the database of a major German national health insurance. The study design was approved by the responsible research ethics board. Fee codes and treatment dates allowed for tracing clinical courses. Only data from patients who had been members of the insurance for the whole six-year period 2012 to 2017 were included. Statistical Methods comprised Kaplan-Meier-survival-analyses. All FDPs were metal based with optional ceramic veneering on the vestibular aspect of incisors, canines and premolars (except for teeth 35 and 45). Four study groups (1 to 4) with replacement of one tooth, two teeth, three teeth and four teeth were formed. The primary outcome was the extraction of an abutment tooth. A second analysis was conducted for the combined target event removal of a retainer crown or extraction of an abutment tooth.
Results: A number of 124,136 FDPs were traced after placement (group 1: 93,816; group 2: 24,216; group 3: 4,459, group 4: 1,645). The cumulative six-year survival rates for the primary outcome extraction were 96.0 % for group 1, 95.6 % for group 2, 95.1 % for group 3 and 98.3 % for group 4. The cumulative six-year survival rates for ”removal or extraction” were 83.0 % for group 1, 78.1 % for group 2, 74.0 % for group 3 and 94.4 % for group 4.

Conclusions: This study confirmed a good mid-term survival of FDP abutment teeth and performance of FDPs under the terms and conditions of the German national health insurance system.