A Study of a Surgical Guide for Dental Implantology
Condition: Dental Implantation, Endosseous; Dental Implants; Minimally Invasive Surgical Procedures; Surgery, Oral; Surgery, Computer-Assisted
Study type: Interventional

Summary: 
      This is a prospective, adaptive, parallel study with four arms, which seeks to compare the
      accuracy of freehand and guided dental implantation surgeries. The basis of the comparison in
      each case is a digital plan, and that digital plan is compared to the actual postoperative
      status by computerized, three dimensional analysis.
    

Detailed description: 
      Osseointegration of endosseous implants has long been the focus of research in dental
      implantology, for obvious reasons. The use of Titanium became the standard quite soon, but it
      took decades of research to come up with the ideal shapes and surface modifications (both
      physical and chemical), so that today it is safe to assume that a properly placed
      commercially available dental implant will osseointegrate. The issue of osseointegration can
      thus be considered as practically resolved, and this traditional surface-oriented line of
      implant research now focuses on modifications to prevent complications, such as
      peri-implantitis (7). It must be seen, though, that for decades, the main goal was to keep
      the inserted implant in place, which pushed other important issues aside, such as the three-
      dimensional position of the inserted (and osseointegrated) implant in the bone. The lack of
      adequate imaging technologies also contributed to the paucity of research in this direction
      and clinicians - having no other option - started to plan implant positions in panoramic
      radiograms and perform implant surgeries relying on their ability to mentally merge those
      two- dimensional plans with patient anatomy. Today, this can be considered the standard
      approach to dental implant surgery.

      The optimal positioning of the implant in the patient's bone is, in many respects, an issue
      of distinguished importance. First, the position of the implant has a profound impact on the
      fit of and stress distribution on the superstructure (i.e. crown or bridge), which, in turn,
      influences survival of the latter. The position of the implant also determines the
      distribution of stress in the supporting bone, which, ultimately, influences the long-term
      survival of the implant itself. In other words, a misplaced implant may be functional for
      some time, but will not survive in the long run. Finally, a misplaced implant can cause
      serious esthetic problems in the esthetic zone.

      The rapid progress of information technology and digital image processing created a favorable
      environment for what may be called digital dentistry, including the computer-assisted, three-
      dimensional planning of implant surgery and the stereolithographic manufacturing of surgical
      guides based on such digital plans. Various systems and procedures exist, but cone-beam
      CT-based digital planning and the production of custom-made surgical guides are shared
      features. The studied SMART Guide guided system is unique in the sense that the entire
      process is digital, and no dental technical work is required.

      The aim of such a guided system is to provide individualized patient care by a.) planning
      implant position(s) considering the individual patient anatomy and b.) manufacturing a
      custom-made surgical guide that serves to guide bone drills during the preparation of the
      bony bed of the planned implant. The custom-made guide is manufactured according to the
      digital plan. The result is a surgical accessory that exactly fits the remaining dentition of
      the patient (thereby stabilizing it) and ensures that the bony bed of the implant is prepared
      as planned. Meta-analyses show that these systems indeed allow highly accurate implant
      placement as compared to the plan. But is this any better than the traditional, freehand way
      of implant surgery and placement? Intuitively, one would answer yes, but, in fact, the
      question is quite difficult to answer, given the almost complete lack of studies on the
      accuracy of freehand implant placement. Therefore, one of the aims of this study is to make
      such a comparison. A further point is that in the everyday practice, surgical guides are used
      in either of the following three modalities: for the initiation of the bed preparation
      ("pilot"), for the initiation and the entire drilling process ("partial") and for the entire
      process including the insertion of the implant ("full"). It is assumed that the more
      extensively the guide is used, the more accurate the final implant position will be as
      compared to the plan. However, this is only an assumption, as no direct comparison is
      available. Therefore, it is also our aim to compare these modalities in terms of how accurate
      implantation they allow as compared to the plan.

      The investigators hypothesize that all three guidance modalities will allow significantly
      more accurate implant placement than the freehand method. It is also hypothesized that the
      three modalities will differ in the accuracy they allow. In general, the investigators
      hypothesize that any form of guided implant surgery and placement yields significantly more
      accurate results than the freehand approach.

      Primary aim Comparison of the accuracy of partially and fully guided implantation as
      indicated by angle deviation.

      Secondary aims

      The secondary aims of the study are as follows:

      To compare the accuracy of the different methods as indicated by entry point deviation; To
      compare the accuracy of the different methods as indicated by apical deviation; To compare
      the accuracy of the different methods as indicated by volume overlap; To compare the
      influence of position (maxilla or mandible) on the accuracy of implantation; To assess the
      tolerability of implantation performed with surgical guide; To assess the safety of
      implantation performed with surgical guide; To assess dentist satisfaction with the surgical
      guide (custom questionnaire) To assess volunteer satisfaction (OHIP, custom questionnaire)
    

Intervention name(s): SMART Guide
Intervention type(s): Device
Intervention description(s): The device manufactured according to a digital plan based on patient anatomy. Guiding sleeves are used, through which bone drills are applied. These sleeves sit in a plastic template that is a negative of the patient's dentition, so that the guide is properly stabilized during the operation. The position of the sleeves is calculated from the surgical plan in a way that they guide the drills in the planned position.The material of the template is medical plastic, the sleeves are made of medical steel.The device is applied by the dentist during the implant surgery. The template is placed on the remaining dentition of the patient and stabilized this way. By this, the sleeves are also stabilized in their planned position. Access through the soft tissue can be prepared through the given sleeve with a circular trephine, but the system also supports flap surgery. As access has been established, the dentist performs the surgical protocol as planned.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment