Clinical performance of one‐piece screw‐retained implant crowns based on CAD/CAM hand‐veneered zirconium dioxide customized abutments with a 6 years and 7 months mean follow‐up

Abstract

Background : The choice of the implant abutment is one of the key factors for success in implant therapy. Titanium abutments are currently the preferred material option for implant crowns, Nonetheless, the major drawback is its dark color and the grayish appearance. The use of onepiece CAD/CAM individually customized zirconia implant abutments, as an alternative to titanium abutments, is steadily increasing. However, there are only few studies reporting results on this type of reconstructions after 5 years. Aim/Hypothesis : To assess the clinical and esthetic outcomes and patient satisfaction of screw-retained one-piece implant crowns fabricated with zirconia abutments after a mean follow-up of 6 years and 7 months. Materials and Methods : Thirty-two patients received 40 implant crowns in anterior and premolar sites in both jaws. All restorations were based on ceramic hand-veneered customized CAD/CAM zirconium dioxide abutments. The follow-up consisted on a clinical and radiological examination. The esthetic outcomes were assessed by means of the Pink Esthetic Score-White Esthetic Score (PES-WES) was used to evaluate the esthetic outcome. Patient ' s satisfaction, in regard to function and esthetics, was assessed via VAS scales. Results : Thirty-two patients (12 women, 20 men) with 40 implant crowns attended the follow-up. Implant and prosthetic survival were 100% and 97.5% respectively. Mean marginal bone loss was 0.17 mm (SD 1.16 mm). Probing depth was 4 or less mm in 98.7% and 5 mm in 1.3% of the sites; 8.3% of them were BOP positive. One abutment fracture was found. No further technical or biological complications were observed. Esthetic outcomes: The mean PES and WES scores were 7.0 and 7.1 respectively. Patient ' s satisfaction: VAS scores of 9.41 and 9.26 (10-point VAS scale) for function and esthetics respectively showed high patient satisfaction. Conclusions and Clinical Implications : After a 6 years-7 months mean observation period, screw-retained implant crowns based on veneered customized CAD/CAM zirconia abutments with a Cross-Fit connection showed to be a reliable treatment option for the replacement of missing teeth in the anterior and premolar region. Patient satisfaction was high and periimplant tissues were stable and healthy. Nevertheless, cautious case selection is recommended for the use of these type of crowns in free-end saddles in patients with parafunctions.