Two Implants Versus One Implant With a Cantilever - a Randomized Controlled Clinical Trial

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
University of Zurich Identifier:
First received: July 20, 2012
Last updated: February 4, 2014
Last verified: February 2014

The aim of the present study is to test whether there is a difference in the marginal bone level change between implants with and without cantilevers.

Condition Intervention
Dental Implants
Procedure: 1 Implant
Procedure: 2 Implants

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Supportive Care

Further study details as provided by University of Zurich:

Primary Outcome Measures:
  • radiographic bone level [ Time Frame: 5 years ] [ Designated as safety issue: No ]
    The primary endpoint of the study is the radiographic bone level 5 years after insertion.The bone level represents an indicator of the osseointegration and biological success of the implant.

Secondary Outcome Measures:
  • Radiographic bone level [ Time Frame: 1 and 3 years ] [ Designated as safety issue: No ]
  • Implant survival and success [ Time Frame: 1, 3, 5 years ] [ Designated as safety issue: No ]
  • rate of technical complication [ Time Frame: 1, 3, 5 years ] [ Designated as safety issue: No ]
    technical complications: screw loosenings, screw fractures, framework fractures, veneering ceramic fractures

  • rate of biological complications [ Time Frame: 1, 3, 5 years ] [ Designated as safety issue: No ]
    biological complications: mucositis, assessed by bleeding on probing

  • Soft tissue changes [ Time Frame: 1, 3, 5 years ] [ Designated as safety issue: No ]
    Soft tissue changes: change in clinical crown length = recession / papilla index

  • Patient morbidity [ Time Frame: 1, 3, 5 years ] [ Designated as safety issue: No ]
    VAS scale to assess pain after implant placement

Estimated Enrollment: 34
Study Start Date: July 2012
Estimated Primary Completion Date: December 2018 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Test group
1 Implant, to be placed in the position with greater vertical bone height with a mesial or distal cantilever.
Procedure: 1 Implant
Active Comparator: Control group
2 Implants
Procedure: 2 Implants


Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • male and female patients 18 years to 80 years of age
  • no general medical condition which represents a contraindication to implant treatment
  • two adjacent missing teeth in the maxilla or mandible in positions of premolars and molars
  • at least one tooth present adjacent to the edentulous space
  • indication for implant treatment is given
  • at least 8 mm of vertical bone height in the mandible allowing for the placement of a 6 mm implant (2 mm safety distance to inferior alveolar nerve)
  • at least 4 mm of vertical bone height in the maxilla
  • signed informed consent after being informed

Exclusion Criteria:

  • smoking of more than 15 cigarettes a day (clinical studies show an increased failure rate of implants in heavy smokers)
  • poor oral hygiene after hygienic phase (Plaque Index over 30 %)
  • active periodontal disease
  • pregnancy or breastfeeding at date of inclusion
  Contacts and Locations
Please refer to this study by its identifier: NCT01649531

Center of Dental Medicine Clinic of Fixed and Removable Prosthodontics and Dental Material Science
Zurich, Switzerland, 8032
Sponsors and Collaborators
University of Zurich
Principal Investigator: Karin Wolleb, Dr. Center of Dental Medicine Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich
  More Information

No publications provided

Responsible Party: University of Zurich Identifier: NCT01649531     History of Changes
Other Study ID Numbers: 2012-0097
Study First Received: July 20, 2012
Last Updated: February 4, 2014
Health Authority: Switzerland: Ethikkommission processed this record on April 20, 2014