Clinical performance of implant crowns with customized zirconia abutments: A prospective cohort study with a 4.5-to 8.8-year follow-up

Objective To assess the clinical and esthetic outcomes and patient satisfaction of screw-retained one-piece implant crowns fabricated with zirconia abutments after a 4.5- to 8.8-year follow-up. Material and methods Thirty-two patients (12 women and 20 men), who received 40 implant single crowns in anterior and premolar sites, were included in this prospective study. All restorations were based on ceramic hand-veneered customized CAD/CAM zirconia abutments. The follow-up consisted of clinical and radiological examinations. The pink esthetic score-white esthetic score (PES-WES) was used to evaluate the esthetic outcome. Patients' satisfaction was assessed via visual analog scale (VAS). Results Implant and prosthetic survival rates were 100% and 97.5%, respectively. Mean marginal bone loss was -0.17 mm (SD 1.16 mm). Probing depth was <= 4 mm in 98.7% and 5 mm in 1.3% of the sites; 8.3% of them were bleeding on probing positive. No technical or biological complications were observed except for one abutment fracture. The mean PES-WES scores were 7.0 and 7.1, respectively. VAS scores (10-point) of 9.41 for function and 9.26 for esthetics showed high patient satisfaction. Conclusion After a mean observation period of 6 years and 7 months, screw-retained implant crowns based on veneered customized CAD/CAM zirconia abutments with conical connection showed very good clinical performance and may be recommended for the replacement of missing anterior and premolar teeth. (ClinicalTrials.gov # NCT04370314).