International Poster Journal of Dentistry and Oral Medicine



Forgotten password?


Int Poster J Dent Oral Med 7 (2005), No. 1     15. Mar. 2005

Int Poster J Dent Oral Med 2005, Vol 7 No 01, Poster 256

Single-stage procedure of implants with micro- and macro-threads in the toothless maxilla
Two year results

Language: English

Argiris Samiotis, Dr. Helmut G. Steveling
Department of Oral and Maxillofacial Surgery, University of Heidelberg, Germany (MZK-Klinik, Abt. MKG-Chirurgie, Universität Heidelberg)

27.-29. November 2003,
15. DGI - Jahrestagung,
Göttingen, Germany


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 (Figs. 1, 2). The design of the implant corresponds to the Astra-Tech single-tooth implant, which has been on the market since the late 80s.

Fig. 1 Fig. 2

Material and methods

Fifty four patients (mean value 55.2 years old) with a toothless maxilla were provided with a total of 374 implants. Most of these implants (222) were inserted into type B III bone. Table 1 shows the distribution of bone quantity and quality.

The patients were provided with between 5 and 10 implants. Table 2 shows the distribution of the implants according to diameter and length, Table 3 the number of implants per patient in the individual centres. All implants were inserted under local anaesthesia and preoperative antibiosis by means of 3 million units of penicillin. Then, healing abutments with a length visibly protruding from the level of the mucosa were placed onto the implants.
After one week, in which the patients did not wear any dental prosthesis, the sutures were removed. The existing total prosthesis was provided with a hollow grinding and a permanently smooth lining and was then reinserted. Table 4 shows the distribution of the patients according to age (mean value 55.2 years) and gender. Table 5 shows the smoking habits of the 54 patients.
Intraoral X-ray pictures in orthogonal technique were obtained immediately after surgery or upon removal of the sutures. After a healing period of six months, the patients were provided with permanent restaurations. Further X-ray controls by means of intraoral dental films were performed immediately after insertion of the prosthetic supraconstruction. These radiological controls were repeated after 6, 12 and 24 months.


During the healing phase of six months, 22 of the 374 implants were lost, i. e. the survival rate was 91.2%. Table 6 shows the distribution of the lost implants according to diameter and length. 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%) (Table 7). No further implants were lost during the 24-months long controls. Tables 8 and 9 show the measurements between basing point and marginal bone level at the different control dates. 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. This is demonstrated by the slight increase in the diagram shown below (Table 10).

Tab. 6

Tab. 7

Tab. 8

Tab. 9

Tab. 10


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.

This poster was submitted by Argiris Samiotis.

Argiris Samiotis
Department of Oral and Maxillofacial Surgery, University of Heidelberg
MZK-Klinik, Abt. MKG-Chirurgie, Universität Heidelberg
69120 Heidelberg