Bi‐layered zirconia/fluor‐apatite bridges supported by ceramic dental implants: a prospective case series after thirty months of observation

Objective The aim of this study was to determine the success and survival rate of all‐ceramic bi‐layered implant‐supported three‐unit fixed dental prostheses ( IS ‐ FDP s) 3 years after implant placement. Material and methods Thirteen patients (seven males, six females; age: 41–78 years) received two one‐piece ceramic implants (alumina‐toughened zirconia) each in the region of the premolars or the first molar and were finally restored with adhesively cemented bi‐layered zirconia‐based IS ‐ FDP s (3 in the maxilla, 10 in the mandible) composed of CAD / CAM ‐fabricated zirconia frameworks pressed‐over with fluor‐apatite glass‐ceramic ingots. At prosthetic delivery and the follow‐ups after 1, 2 and 3 years, the restorations were evaluated using modified United States Public Health Service ( USPHS ) criteria. Restorations with minor veneer chippings, a small‐area occlusal roughness, slightly soundable restoration margins, minimal contour deficiencies and tolerable color deviations were regarded as success. In case of more distinct defects that could, however, be repaired to a clinically acceptable level, IS ‐ FDP s were regarded as surviving. Kaplan–Meier plots were used for the success/survival analyses. To verify an impact on subjective patients’ perceptions, satisfaction was evaluated by visual analog scales ( VAS ). Results All patients were seen 3 years after implant installation. No IS ‐ FDP had to be replaced, resulting in 100% survival after a mean observation period of 29.5 months (median: 30.7). At the 3‐year follow‐up, 7/13 IS ‐ FDP s showed a veneer chipping, 13/13 an occlusal roughness and 12/13 minimal deficiencies of contour/color. Since six restorations showed a major chipping and/or a major occlusal roughness, the Kaplan–Meier success rate was 53.8%. However, patients’ significantly improved perceptions of function, esthetics, sense, and speech at prosthetic delivery remained stable over time. Conclusion Bi‐layered zirconia/fluor‐apatite IS ‐ FDP s entirely survived the observation period but showed a high frequency of technical complications. Nevertheless, the treatment highly satisfied patients’ expectations.