To Compare Cemented Versus Screw-retained Implant-supported Single Crowns With Customized Zirconia Abutments
The aim of this study is to test whether or not the use of screw-retained implant crowns on customized zirconia abutments results in biological, technical and esthetic outcomes similar to those obtained with cemented all-ceramic crowns on customized zirconia abutments, both made with a computer-aided design and manufacturing procedure (CAD/CAM).
The null-hypotheses is that marginal bone level change is equal at screw-retained and cemented crowns
|Implant-supported Single Crowns||Procedure: Cemented crowns Procedure: Screw-retained crowns|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: No masking
Primary Purpose: Supportive Care
|Official Title:||A Randomized Controlled Clinical Trial Comparing Cemented Versus Screw-retained Implant-supported Single Crowns With Customized Zirconia Abutments|
- Marginal bone level [ Time Frame: 5 years ]The bone level represents an indicator of the osseointegration and biological success of the implant.
- Biological, technical and esthetic outcome [ Time Frame: up to 5 years ]Radiographic bone level after 1 and 3 years
- Biological, technical and esthetic outcome [ Time Frame: up to 5 years ]implant survival after 1, 3 and 5 years
- Biological, technical and esthetic outcome [ Time Frame: up to 5 years ]rate of biological complications after 1, 3 and 5 years
- Biological, technical and esthetic outcome [ Time Frame: up to 5 years ]rate of technical complications after 1, 3 and 5 years
|Study Start Date:||June 2012|
|Estimated Primary Completion Date:||December 2018 (Final data collection date for primary outcome measure)|
Active Comparator: Cemented single crowns
Cemented single crown: zirconia abutment (Straumann Cares abutment) with an all-ceramic lithium disilicate crown
Procedure: Cemented crowns
The final lithium disilicate crowns will be cemented with an adhesive cement after tightening the abutments with the torque indicated by the manufacturer and closing the screw access hole with white guttapercha. The abutment will be cleaned with ethanol. A retraction cord will be placed for cementation if indicated. The crown will be etched with hydrofluoric acid and subsequently silanized. A sufficient amount of cement will be filled in the crown without creating major excesses. When the crown is seated correctly, the cement will be light-cured for a few seconds to facilitate the removal of the now hard excess cement.
- Excess cement will be meticulously removed with a carbon scaler. The removal of all excess cement will be checked with an X-ray and by visual and tactile inspection.
Active Comparator: Screw-retained single crown
Screw-retained single crown: zirconia abutment (Straumann Cares abutment), directly veneered with veneering ceramic
Procedure: Screw-retained crowns
The screw-retained crowns will be inserted and tightened with the torque indicated by the manufacturer. The screw access hole will to be closed with white guttapercha and a composite filling (Filtek, 3M ESPE).
Please refer to this study by its ClinicalTrials.gov identifier: NCT01644630
|Center of Dental Medicine Clinic of Fixed and Removable Prosthodontics and Dental Material Science|
|Zurich, Switzerland, 8032|
|Principal Investigator:||Daniel Thoma, PD Dr.||Center of Dental Medicine Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich|