THE ENDO-OSSEOUS ZIRCONIA SIGMA IMPLANT

The second generation SIGMA Implant, realised according to the Alexa III method, is the fruit of long years of research. The physical properties of this bio ceramic material (zirconium oxide) is 5 times higher to that of ceramic material of the 1st generation (sintered aluminium).

This new revolutionary material is made of a zirconium based ceramic reinforced during a thermic and physical production process. Its resistance has been particularly enhanced by a regular crystal sorting technique linking them with appropriate materials.

Perfectly biocompatible and given its excellent physical properties, zirconium is well adapted to biomedical use. Its shining aspect and its colour are close to that of ivory, which make it a reference material for epithelial junctions. Increasingly high quality standards and the need to dispose of materials being able to withstand the weights they are submitted to, requires very particular treatment. The crystalline products are grounded to dust and compressed by isostatic processes at high temperatures going up to 2000°C. The HIP (High Isostatic Pressure) makes the combination of materials possible, which would have been impossible under fusion. During the HIP installation, the combination of heat and pressure induces a process of porosity elimination. This way, we are able to obtain a maximum density and an improvement of the dynamic resistances of up to 100% simultaneously. The liquefaction of the material insures its homogeneity. After cooling and drying the material, the pure zirconium powder of defined granularity is pressed in high temperature moulds thus obtaining homogenised implants, of perfect dimensional likeness.

A production protocol is established for each series of the SIGMA implants.

In biotechnology, a domain where the imperatives of bio-mechanics are very high, zirconium has become a reference material.

The production processes of the SIGMA implants are submitted to regular and minute tests. These particularly severe controls have conferred a quality label to the SIGMA endo-bone implant. The strict observation of the rules and of the quality criteria all along the production process gives the SIGMA implants an incomparable biological safety. The constant concern for improvement is the best guarantee for success for patients and practitioners.

Amongst the production controls, the most important are:

- Determining the degree of purity of the material and the respect of the granularity proportions of the powder;
- The control of the shaping of implants by pressing at very high pressures, all being regulated by a computer;
- Homogeneity control (thanks to the ZIGLO penetration process);
- Control of the volume exactness thanks to specialised measuring tools;
- testing the resistance to twisting and bending of the material by dynamometric apparati;
- Control of the profile on the screen to determine the exactness of the pivot-rings.

The SIGMA implant is corrosion proof. It is chemically and electrically neutral. Its colour guarantees aesthetic perfection. Its reduced size takes into account the available space on the jaw-bone without interfering with the mechanic resistance of the bone, where it is destined to live.

The cylinder shape, the pivot-rings and the whorls represent a support surface which enables the bone to heal in 3 to 4 weeks after the installation of the implant.

The configuration of the stringage is made to insure the immediate retention of the SIGMA implant and favours the bone and cartilage regeneration.

The non-invasive surgery technique offers the great safety to users, particularly thanks to a well studied instrumentation and ergonomics (see ancillary material).

The SIGMA implant being two-folded can be used in superficial and buried (internal) surgery.

Amongst the qualities treated above, one must underline the perfect radio -opacity of the material, which in no way interferes with modern medical imagery techniques, i.e.:

- Tomodensitometry (SCANNER);

- Nuclear magnetic resonance imagery (RMNI)