[Endosseous titanium implants as orthodontic anchoring elements. Experimental studies and clinical application]

Abstract

Part 1 of this study, which deals with experimental use of titanium implants in animals (Brånemark, dimension 10 x 3.75 mm), examines the long-term orthodontic application of force on the quantity of peri-implant and paraimplant bone and on direct bone contact (in %) at the implant surface. In the experiment 6 premolars (P3 mandible/maxilla and P4 mandible) were extracted from each of 2 foxhounds. After 12 weeks each dog received 6 implants (P3 and P4 areas). After the implants had healed for 25 weeks, the fixtures in the P3 areas were used as anchoring elements (test implants) for P2 distalization over a period of 26 weeks (continuous force applied: approximately 2 N). The implants in the P4 area served as the control group. Histological analysis revealed in the test implants (mandible) in comparison to the control implants (mandible) the following differences: broader cortical bone; wider peri-implant bone casing; denser, partly sclerotic spongiosa (pressure side); and thicker trabecula (tension side). Fluorescence microscopy revealed that these findings were the result of distinct lamellar bone apposition during the force application phase. In comparison, far less lamellar apposition was found in the test implants (maxilla). The mean percentage of direct bone contact at the implant surface was: Control implants (mandible, n = 4): 40.5%; test implants (mandible, n = 4): 51.6%; and test implants (maxilla, n = 4): 42.4%. Part 2, the clinical portion of the study, presents the suitability and feasibility of using endosseous implants as orthodontic anchoring elements, first, for orthodontic-prosthetic anchoring, and, second, for orthodontic anchoring only. Further, the significance of these aspects in relation to the implant site, to implant dimension, and to the type of implant anchoring are recorded.