Long-term clinical, technical, and esthetic outcomes of all-ceramic vs. titanium abutments on implant supporting single-tooth reconstructions after at least 5 years

AIM The aim of this prospective cohort study was to evaluate clinical, radiographic, technical, esthetic, and patient-centered outcomes of implants using two different restoration materials after 5-9 years. MATERIALS AND METHODS The study included 28 patients (test group: 13 patients with all-ceramic crowns on aluminum oxide-based abutments; control group: 15 patients with metal abutments on porcelain-fused-to-metal crowns). Evaluation of patient satisfaction, clinical (periodontal probing depth, bleeding on probing, plaque index, mucosal recession, and width of keratinized mucosa), esthetical (papilla index, clinical crown length), technical (loss of retention, marginal adaptation, chipping of ceramic, anatomical shape, occlusal wear, color match), and radiological parameters were assessed. The statistical analyses included comparison of all-ceramic vs. metal abutments and between the groups using Mann-Whitney U-tests. For esthetic parameters, changes over time were assessed using Friedman test and post hoc Wilcoxon test of all complete cases. RESULTS The survival rate of the restoration was 100% in both groups. Patient's satisfaction revealed 9.7 on the visual analog scale. A low satisfaction correlated with low ratings in color or anatomical shape. The mucosal recession in the test group was less than that in the control group. An increase in distal papilla height in the year 0 to 1, and a decrease from year 1 to 8, was detected. Sites, which received a soft tissue graft, revealed stable papillae over the observation period. Clinical crown length showed higher values in the control group. CONCLUSIONS Within the limitations of the study, it can be concluded that all-ceramic restorations reveal a high survival rate of 100% and show no difference to metal after a mean observation period of 7.2 years