Clinical trials on implants in regenerated bone.

The lack of a sufficient volume of healthy jaw bone was the most important local contraindication for the placement of dental implants in the 1980s. Thus, several attempts have been made in the past 10 years to develop new surgical methods for the reconstruction of lost jaw bone in potential implant patients. At present, methods such as guided bone regeneration utilizing barrier membranes or sinus lift procedures are widely used in dental offices. There are, however, some concerns about the efficacy and predictability of these procedures. There is a need to determine how new bone regenerative procedures should be properly evaluated. The goal of the present paper is to establish some guidelines for clinical trials on implants in regenerated bone. It is proposed that such trials should be conducted in two main phases according to predetermined endpoints. The first main phase evaluates the new bone regenerative procedure. This almost always requires an initial development period including step-by-step modifications to identify essential surgical factors for the achievement of successful treatment outcomes. At the end, the surgical protocol will be established in detail. This is followed by the validation period to evaluate efficacy and predictability of this surgical protocol in a clinical study with consecutively treated patients. After successful bone regeneration has been properly documented, the second main phase evaluates the implants inserted in regenerated bone in a prospective clinical study utilizing the same protocol as for implants in pristine, non-regenerated bone. This documentation allows the evaluation of tissue integration of these implants and their 5-year success rates.