Peri-Implant Healing Around Two Different Machined-Collar Designs After 25 Years of Function
Condition: Jaw, Edentulous
MeSH terms: Jaw, Edentulous
Study type: Interventional

Summary: 
      Brånemark System® dental implant osseointegration was introduced in 1965 as a novel approach
      to the replacement of missing teeth. Although this implant's machined, screw-shaped surface
      had excellent, well-documented, short- and long-term clinical success (Adell, R. 1987;
      Albrektsson, T., et al., 1981; Albrektsson, T., et al., 1986; Brånemark, P-I. , 1983;
      Brånemark P-I. 1987), newer implant designs were introduced that could enhance fusion of the
      implant to jaw bones, and better resist functional forces. One such implant, Screw-Vent®, has
      a fixture macro structure very similar to that of the Brånemark® implant. However, its
      fixture surface was acid etched (1-3µm) which could enhance osseointegration, and it has a
      longer, narrower machined internal-hex, friction-fit collar that could better resist
      functional forces.These characteristics should lead to less bone loss (Niznick, G. A., 1989).
      However, one clinical study (De Bruyen, et al., 1992) reported greater short-term bone loss
      with this implant compared to the Brånemark® implant, possibly due to its longer machined
      collar, and advocated long-term clinical studies. Therefore, this prospective within-subject
      clinical trial was undertaken in 1993 to first compare the Brånemark® implant with another
      implant, Swede-Vent®, a copy of the Brånemark® macro structure except for its fixture surface
      that was identically micro textured as that of Screw-Vent® by the same manufacturer. The
      effect on bone healing could then be compared between Brånemark®'s machined and Swede-Vent®'s
      micro textured fixture surfaces in the short- and long-terms. Since Screw-Vent®'s fixture
      surface was identically micro textured as that of Swede-Vent®, the investigators could then
      evaluate and compare the effects on bone healing of Screw-Vent®'s longer, narrower,
      internal-connection machined collar to the identical shorter, wider, external-connection
      machined collars of the Swede-Vent® and Brånemark® implants. All three two-part,
      platform-matched, parallel-wall implants were made of commercially pure titanium, had a very
      similar fixture macro design, were approved by the Food and Drug Administration (USA) and
      Health and Welfare Canada, and were commercially available in North America. Brånemark® and
      Screw-Vent® implants are still available, but the Swede-Vent® implant is not.
    

Detailed description: 
      Therefore, between 1993 and 1996, 58 of 60 eligible participants had been recruited into a
      prospective, randomized clinical trial. This trial had been peer reviewed, had received
      ethical approval, and had taken place at the Université de Montréal's Faculty of Dental
      Medicine and its affiliated hospital dental department. Follow-up documentation occurred at
      one year, two years, and 15 to 20 years following prostheses attachment (ClinicalTrials
      Identification Number NCT01641198), and the results were published (Camarda, et al., 2018).
      The present study reports on data collected at the 25-year (24.6 ± 0.19 years, mean ± SE)
      follow-up (ClinicalTrials Identification Number NCT03862482), focusing specifically on the
      evaluation and comparison of the effects on peri-implant healing and functional
      osseointegration of the two different machined collar designs. That is to say, the identical
      shorter, wider, external-connection Brånemark® and Swede-Vent® collars versus the longer,
      narrower, internal-connection Screw-Vent® collar. Twenty-two of the original participants
      (41.5%, age 71.1 ± 1.2 years, 11 women, 110 implants) were enrolled into this study. All
      study procedures were performed in accordance with the Helsinki Declaration and its later
      amendments, and all participants signed informed consent documents prior to inclusion into
      this study.
    

Intervention name(s): Brånemark® 2, Swede-Vent® 2, Screw-Vent® 1 (Configuration 1); Brånemark® 1, Swede-Vent® 2, Screw-Vent® 2 (Configuration 2); Brånemark® 2, Swede-Vent® 1, Screw-Vent® 2 (Configuration 3)
Intervention type(s): Device; Device; Device
Intervention description(s): Brånemark® implant placed at sites 2 (left medial) and 5 (right distal), Swede-Vent® implant placed at sites 1 (left distal) and 4 (right medial), Screw-Vent® implant placed at site 3 (para symphysis); Brånemark® implant placed at site 3 (para symphysis), Swede-Vent® implant placed at sites 2 (left medial) and 5 (right distal), Screw-Vent® implant placed at sites 1 (left distal) and 4 (right medial); Brånemark® implant placed at sites 1 (left distal) and 4 (right medial), Swede-Vent® implant placed at site 3 (para symphysis), Screw-Vent® implant placed at sites 2 (left medial) and 5 (right distal)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Treatment
Keywords: Dental Implants, Microtextured Fixture, Machined Collar