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OpenTrials
Completed

NCT Number: NCT01644630

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

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Key information

Conditions

Implant-supported Single Crowns

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Clinic of Reconstructive Dentistry

Zurich, 8032, Switzerland

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Cemented crowns

Procedure

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.

Screw-retained crowns

Procedure

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).

Primary outcomes

  1. Marginal bone level

    Time frame: 5 years

    The bone level represents an indicator of the osseointegration and biological success of the implant.

Secondary outcomes

  1. Biological, technical and esthetic outcome

    Time frame: up to 5 years

    Radiographic bone level after 1 and 3 years

  2. Biological, technical and esthetic outcome

    Time frame: up to 5 years

    implant survival after 1, 3 and 5 years

  3. Biological, technical and esthetic outcome

    Time frame: up to 5 years

    rate of biological complications after 1, 3 and 5 years

  4. Biological, technical and esthetic outcome

    Time frame: up to 5 years

    rate of technical complications after 1, 3 and 5 years

Sponsors and collaborators

Lead sponsor

University of Zurich

Other

Registry information

Official study title

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

Important dates

Study start
2012
Primary completion
2019
Study completion
2019
First posted
Jul 19, 2012
Registry last updated
Nov 6, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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