Anodizing
Biological growing together with a living tissue iscontraindicated to the surface of external parts of prosthetic suprastructures (so-called prosthetic components) such as the abutments, healing abutments, transfers, etc.as distinguished from the implants embedded into the bone or mucous tissue. Thus, the principles of its machining must be fundamentally different. The surface of external prosthetic components must be neither rough nor porous, but vice versa an ideally smooth if possible (to minimize the ingrowth of living tissue in them) and hard (to minimize the mechanical chafing – wear).
Solid-State Anodizing
The classic methods of grinding or polishing are little applicable for the surfaces of majority of the prosthetic components due to their small sizes. To attain an ideally smooth or hard surface of some prosthetic components, they are subjected to electrolytic oxidation in the acid electrolytes, so-called solid anodization. Its point lies in the fact that a solid oxide film up to 50 µm thick having a wonderful adhesion to the base metal is deposited (grown) on a part serving as an anode in the electrical circuit formed in the electrolytic bath (as a rule based on the sulfuric, chromic or oxalic acids). The method of solid-state anodization essentially surpasses the method of metal air oxidation at a high temperature in the thickness of oxide film and its adhesive strength to the base metal.
By indications of technological nature, only three structural metals – aluminium, titanium, and tantalum - may be subjected to the electrochemical anodization with a hard and strong oxide film being obtained in the real manufacturing practice. Two of these metals (titanium and tantalum) are the important medical grade metals widely used in manufacturing of medical products. The technology of solid anodization of the prosthetic components made of titanium and tantalum is well-mastered by the manufacturing of the ABM Technology Medical Product Plant, and with this end in view, we have all necessary electrochemical equipment (manufactured by Swiss KKS Ultraschall AG) of the top class and quality.
Colour Anodizing
However, the technologies of electrochemical treatment of medical grade metal surface do not reduce themselves only to a solid-state anodization. In order to lighten the work of prosthetic surgeons, such method of treatment of titanium surface of the prosthetic components as colour anodizing is also mastered at our Plant.
In this technology, the titanium surface of the prosthetic elements is painted in different hues of colour spectrum, which is attained by a combining of the electric current voltage, electrolyte composition, and carrying out the anodizing. This is done for the prosthetic surgeon’s convenience, whom is rather easily and simpler work during the surgical operation with small-sized prosthetic components of different nomenclature painted in a definite colour.
Moreover, coloured oxide film obtained by method of electrochemical anodizing has a multiply better adhesion (strength of attachment to the base) than any known paint-and-lacquer coating. And unlike the paints and lacquers, which usage is contraindicated in the prosthetic surgery, this film has a good biological neutrality, which characteristics are close to the medical grade base metal.