ITI IMPLANTS IN COMBINATION WITH BONE-GRAFTS - DESIGN AND BIOMECHANICAL ASPECTS

In this article we describe the implantation of ITI implants in combin ation with bone grafts. Two different cases were considered: the augme ntation of an atrophic maxilla or mandible where the transplant was fi xed by means of ITI implants and the implantation into free transplant s fixed by means of the THORP reconstruction plate system. These indic ations require 2-stage procedures with submerged implants and transpla nts during the healing period. For this new applications, standard ITI implants were combined with specially developed new transgingival uni ts of high manufacturing precision. The new design resulted in a maxim um tightening moment of 4.0 N . m versus 1.25 N.m achievable with a co nventional 2-mm screw. Dynamic resting showed that, for the range of t ightening moments of 0.25 N . m up to 1.0 N.m, the loosening moment af ter 2,000,000 cycles remained approximately 10% above the tightening m oment. For the clinical application a tightening moment of 0.35-0.5 N . m is recomme nded. The special design and the high precision of the extension parts results in a tight adaptation between the primary impl ant and the extension parts, which may be important for microbiologica l reasons.