To Compare Cemented Versus Screw-retained Implant-supported Single Crowns With Customized Zirconia Abutments

Study Overview
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Brief Summary
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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

Official Title
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A Randomized Controlled Clinical Trial Comparing Cemented Versus Screw-retained Implant-supported Single Crowns With Customized Zirconia Abutments

Conditions
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Implant-supported Single Crowns

Intervention / Treatment
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* Procedure: Cemented crowns
* Procedure: Screw-retained crowns


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Single-tooth Straumann Bone Level in the anterior maxilla or mandible At least one adjacent natural tooth present Implant position enabling both screw-retained and cemented crown Informed consent signed Exclusion Criteria: Smoking more than 15 cigarettes a day Poor oral hygiene (Plaque index over 30%) Pregnancy at the date of inclusion

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Cemented single crowns<br>Cemented single crown: zirconia abutment (Straumann Cares abutment) with an all-ceramic lithium disilicate crown | Procedure: Cemented crowns<br>* 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.<br>|
| Active Comparator: Screw-retained single crown<br>Screw-retained single crown: zirconia abutment (Straumann Cares abutment), directly veneered with veneering ceramic | Procedure: Screw-retained crowns<br>* 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).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Marginal bone level | The bone level represents an indicator of the osseointegration and biological success of the implant. | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Biological, technical and esthetic outcome | Radiographic bone level after 1 and 3 years | up to 5 years | 
| Biological, technical and esthetic outcome | implant survival after 1, 3 and 5 years | up to 5 years | 
| Biological, technical and esthetic outcome | rate of biological complications after 1, 3 and 5 years | up to 5 years | 
| Biological, technical and esthetic outcome | rate of technical complications after 1, 3 and 5 years | up to 5 years |