Reference-based digital concept to restore partially edentulous patients following an immediate loading protocol: a pilot study
Tahmaseb, A.; De Clerck, R.; Eckert, S.; Wismeijer, D.
International Journal of Oral and Maxillofacial Implants 26(4): 707-717
2011
ISSN/ISBN: 0882-2786 PMID: 21841978 Document Number: 650075
To describe the use of a computer-aided three-dimensional planning protocol in combination with previously placed reference elements and computer-aided design/computer-assisted manufacture (CAD/CAM) technology to restore the partially edentulous patient. Mini-implants and/or reference brackets were inserted or positioned in specified locations in a test cast and in two patients prior to imaging to act as definitive fiducial markers. This served as a fixed base to better define a setup for the fabrication of a surgical template used during computed tomographic imaging. A simulated partially edentulous maxilla was used for the study, and two partially edentulous patients participated. With the CT images, a CAD/CAM superstructure was created prior to surgery and inserted immediately after surgery. Fit of the prosthesis was assessed using three-dimensional tension measurements with strain gauges. Mean misfit for all implants in the x-, y-, and z-axes was 26.6, 24.8, and 10.4 μm, respectively. The total misfit calculated according to the Pythagorean theorem was 42.6 μm. Based upon this pilot study in two patients and an in vitro analysis, it appears that the use of reproducible fiducial markers consisting of mini-implants and reference brackets results in the fabrication of an acceptably accurately fitting definitive prosthesis prior to implant placement.