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Comparison of Early and Late Loading in the Edentulous Upper Jaw Using Cresco Prosthetic System on Straumann Implants

This study has been completed.
Information provided by (Responsible Party):
Institut Straumann AG Identifier:
First received: June 16, 2009
Last updated: March 3, 2016
Last verified: March 2016
Comparison of early and late loading of implants supporting full each prosthesis in upper jaw, using the Cresco prosthetic system on Straumann implants. The study hypothesis is that there is no difference between the bone loss (or gain) between the groups.

Condition Intervention Phase
Jaw, Edentulous
Device: Cresco
Device: Straumann components
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A 3 Arm Controlled Randomised Study: Comparison of Early and Late Loading Protocols in Full Arch Reconstructions in the Edentulous Maxilla, Using The Cresco Prosthetic System on Straumann Implants

Further study details as provided by Institut Straumann AG:

Primary Outcome Measures:
  • Bone Level Change on Radiographs [ Time Frame: 3 years after loading ]
    Crestal bone level change at implant margin.The difference between baseline and 3 years after loading.

Enrollment: 36
Study Start Date: October 2004
Study Completion Date: September 2009
Primary Completion Date: February 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Cresco early loading
The implants must be restored (loaded) with a permanent screw retained fixed partial denture (FPD) at 10 days of post surgery
Device: Cresco
Cresco components loading 10 days post surgery
Experimental: Cresco late loading
Healing caps will be placed until loading. The minimum waiting time is 4 weeks, but not before "try ins" to ensure a perfect fit. The implants must be restored (loaded) with a permanent screw retained fixed partial denture (FPD) within 42-56 days (6 to 8 weeks) of surgery.
Device: Cresco
Cresco loading at 6-8 weeks post surgery
Active Comparator: Straumann system late loading
Straumann components loading at 6-8 weeks post surgery
Device: Straumann components
Straumann components loading 6-8 weeks post surgery

Detailed Description:
The study is a controlled randomised study whereby each patient will receive 5-6 implants placed in the edentulous upper jaw supporting a 10-12 unit screw-retained fixed partial denture (FPD). The main objective of the study is to evaluate the performance of Straumann implants supporting a FPD using Straumann Implants and Cresco restorative components in early and delayed loading protocols at one year post-loading. The treatment groups consist of an early loading and delayed loading arm using Cresco restorative components loading time 10 days post surgery and at 6-8 weeks respectively. The control group comprise the standard delayed loading protocol (healing period 6-8 weeks) and Straumann restorative components. The primary objective is to compare changes in crestal bone levels on radiographs between implants in the control group and test groups at 1 year.The patients will be followed for 3 years.

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Males and females must be at least 18 years of age.
  • Be edentulous in the maxilla and subjectively desire an implant supported screw retained FPD
  • The teeth at the implant site must have been extracted or lost at least 3 months before the date of implantation.
  • In the case of Guided Bone Regeneration(GBR) or Guided Tissue Regeneration (GTR) treatments, these procedures must have been completed at least 6 months prior to intended surgery date (to fulfil point 5).
  • Adequate bone quality and quantity at the six, minimum five, implant sites to permit the insertion of Straumann 4.1 and 3.3 mm diameter implants without the use of concurrent bone augmentation techniques. I.e. implant insertion sites must have sufficient bone height such that the implant will not encroach on vital structures and sufficient width that a minimum of 1 mm of palatal and buccal bone will remain.
  • Patients must be committed to participate in the study for three years follow-up examinations

Exclusion Criteria:

  • Presence of conditions requiring chronic routine prophylactic use of antibiotics (e. g., history of rheumatic heart disease, bacterial endocarditis, cardiac valvular anomalies, prosthetic joint replacements)
  • Medical conditions requiring prolonged use of steroids
  • History of leukocyte dysfunction and deficiencies
  • History of bleeding disorders
  • History of neoplastic disease requiring the use of radiation or chemotherapy
  • Patients with history of renal failure
  • Patients with metabolic bone disorders
  • History of uncontrolled endocrine disorders
  • Physical handicaps that would interfere with the ability to perform adequate oral hygiene
  • Use of any investigational drug or device within the 30-day period immediately prior to implant surgery on study day 0.
  • Alcoholism or drug abuse
  • Patients infected with HIV
  • Patients who smoke more than 10 cigarettes per day or cigar equivalents, or who chew tobacco (not greater than 10 cigarette equivalents)
  • Conditions or circumstances, in the opinion of the investigator, which would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance, unreliability.
  • Local inflammation, including untreated periodontitis
  • Mucosal diseases such as erosive lichen planus
  • History of local irradiation therapy
  • Presence of osseous lesions
  • Unhealed extraction sites (less than 3 months post extraction of teeth in intended sites)
  • Bone surgery (bone grafts, guided tissue regeneration technique for bone enhancement) at implant placement.
  • Severe bruxing or clenching habits
  • Persistent intraoral infection
  • Patients with inadequate oral hygiene or unmotivated for adequate home care
  • Lack of primary stability of 1 or more implant(s) at surgery. In this instance the patient must be withdrawn and treated accordingly.
  • Insufficient bone
  • Other: Inability to place implants according to protocol requirements
  Contacts and Locations
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Please refer to this study by its identifier: NCT00922935

STP Oral protetik
Kalmar, Sweden, 39185
Oral rehabilitering
Linköping, Sweden, 58185
Sponsors and Collaborators
Institut Straumann AG
Principal Investigator: Stefan Ellner, DDS, PhD STP Oral protetik, Kalmar, Sweden
Principal Investigator: Asbjorn Jokstad, Professor University of Toronto, Faculty of Denistry, 124 Edward Street, Toronto
  More Information

Responsible Party: Institut Straumann AG Identifier: NCT00922935     History of Changes
Other Study ID Numbers: CR 02/04
Study First Received: June 16, 2009
Results First Received: June 13, 2011
Last Updated: March 3, 2016
Individual Participant Data  
Plan to Share IPD: No

Additional relevant MeSH terms:
Mouth, Edentulous
Jaw, Edentulous
Mouth Diseases
Stomatognathic Diseases
Tooth Diseases
Jaw Diseases
Musculoskeletal Diseases processed this record on April 28, 2017