Functional bioactive nanostructured heterophase implants for treatment of parodontosis
Gizatullin R.M., Arsenev P.A., Borisenko N.I., Gunderov D.V., Gurfinkel L.N., Koledov V.V., Sazanov A.I., Sokov S.L., Chehovoy A.N., Afonova V.S., Kalashnikov V.S.
Innovation dentistry center “Nano-Dent”, Moscow
One of the most actual tasks on the modern state of the art dentistry is to recover biomedical and physiological characteristics of parodontic tissue. This can be achieved using the techniques of Dental Implantation (DI) and Trans Radix Implantation (TRI) by application of the new generation medical materials and nanotechnology . The NiTi shape memory (SM) alloy is considered as one of the most effective functional material due to its outstanding property to change the form under action of external heating.
Comparing with the common polycrystalline alloys of the same chemical composition, the nanostructured Ni-Ti alloys demonstrate the enhanced strength, but less plasticity. Nanocristallization result in the record high breaking point (up to 2700 MPa), yield strength (200 MPa), reactive stress at SM (1300-1500 Mpa), with the SM elongation 20%. Under high temperatures of tests (up to 400-500 C) NiTi alloy also demonstrates the attractive structural stability and properties, including strength up to 1500 MPa and deformability up to 100-120%. Moreover it demonstrates the better functional properties, in particular, SM pseudoplastic strain and phase stability .
Every organic molecule is based on the chains of carbon atoms, therefore the carbon film chains coatings (CFCC) are adequate to the living tissue and find application in medicine . The structure of plasma CFCC (“Tetracarbon”) consists about 99,9% of carbon. Carbon atoms are connected by Sp hybridization into chains of poliyn and policulumen types, oriented normally to the substrate surface. The chains are combined into the single crystal film by the van der Waals forces and form an atomically smooth surface.
CFCC is anisotropic carbon polymer. It is very elastic across the chains and as hard as diamond along the chains. CFCC “Tetracarbon” coating yield to material the exceedingly high thrombus resistively (higher then that of polystyrene) and enhances greatly the biocompatibility of the medical implants and tools, diminishing the probability of the thrombus origin, inflammation and implants tearing away .
The nanostructural Ni-Ti alloy with the CFCC find its application in dentistry with the aim of movable teeth conservation or radix treatment by TRI. Usually the TRI is performed using NiTi SM implants in combination with porous NiTi (PNT). The PNT particle size is usually about 300 µm. The hetero phase gel composite is introduced into PNT porous which consists of amorphous hydrooxyappatyte and colloid silver (the particle size 20 nm). The resulting hetero phase nanocomposite gel (HPNG) is injected into parodont tissue into the hearth of destruction in combination with TRI or without it.
We report on 87 cases of destructive periodontitis treatment by HPNG and 179 TRI treated cases in combination with HPNG injections during 3 years. Only 7 implants tearing away cases are observed.
It`s noticed, that PNT is actively built into newly generation bone tissue in all the cases of treatment, working as a bone frame with the formation of composite “bone-PNT”. As a result the new regenerative reparative functional structural unit is formed, which we call “Phoenixon”. By formation of Phoenixon the tissue biofunctional ability can be greatly enhanced.
The Fig. 1a shows the typical result of treatment of 23-tooth, 3 month after the injection of HPNG into center of the destruction. The HPNG is recognized as the periapical conglomeration of the oval shape. The Fig. 1b shoes the result 2.5 years after the treatment. PNT granules are integrated with periodontal filaments with Phoenixon formation. The distribution of particles is spherical, which is the most appropriate for optimizing of the damping periodont function. The bone tissue is seen to have the enhanced density.
The signs of resorbtion of 11th tooth radix and the bone around 3 months after TRI due to inflammation are shown on Fig. 2a. Fig. 2b shows the situation 2.5 years after the HPNG treatment. The PNT particles form the write configuration along the force lines. The bone tissue has obviously the enhanced density.
We conclude, that we have tested the DI and TRI implants made of SN NiTi alloy covered be CFCC in combination with HPNG in Innovation Dentistry Center “Nano-Dent”. The nanostructured implants demonstrate extremely high strength and functional properties in almost 100% of cases, with being especially effective in cases with the bone deficit.
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