Poster 256, Sprache: EnglischSamiotis, Argiris/Steveling, Helmut G.An Astra-Tech-Universal implant with a combination of macro- and micro-thread in a single-stage procedure has been applied for prosthetic treatment of the toothless maxilla with a permanent reconstruction in four international centres. The design of the implant corresponds to the Astra-Tech single-tooth implant, which has been on the market since the late 80s.
During the healing phase of six months, 22 of the 374 implants were lost, i. e. the survival rate was 91.2%. Evidently, shorter implants have a much higher loss rate than longer ones. The initial loss rate was significantly higher in smokers (12.7%) than in non-smokers (4.1%). No further implants were lost during the 24-months long controls. In the course of the load duration, a slight consolidation of the marginal bone level by means of a reduction of the distance between marginal bone level and reference point shows after a relatively large initial bone loss of 1.43 mm during the healing phase.
The results regarding the initial bone loss rate correlate with other reports about implants with single-stage procedure in the toothless maxilla. The reconsolidation of the marginal bone level is consistent with the increase of the secondary stability of 2.45 ISQ units that was measured by means of resonance frequency analysis (RFA) in Astra Tech implants in the maxilla. The application of the single-stage procedure technique following the protocol as mentioned in material and methods leads to an average initial bone loss of 1.80 mm (measured from the reference point) which is markedly higher than the bone loss after applying the two-stage technique (0.2 mm) with the same type of implant. Therefore, it is not to be recommended to apply the single-stage procedure with an immediate reinsertion of the soft relined full denture in the toothless maxilla. Smokers, in which the single-stage procedure is applied, have to reckon with a significantly higher implant failure rate than non smokers.
Schlagwörter: single-stage procedure, toothless maxilla, implants with micro- and macro-threads, Astra Tech Implants