The experience of Podolife in the Podiatry sector, consolidated over many years of close contact with specialists in this discipline, has made it possible to collect from the field essential information for the ad hoc development of products designed specifically for the sector, with particular reference to the silicones used for making medical orthoses.
To better understand the technical characteristics that the materials used in medical orthoplastics must have, it is necessary to consider where they are to be applied: delicate situations in which the feet are affected by lesions and/or deformations.
When selecting the materials for foot orthoses, Specialist Podiatrists have two sizeable product categories from which to choose:
– Traditional materials designed for other technological applications
– Innovative materials specifically designed for podiatric use
SILICONE POLYMERS
Silicones are rubbery polymers comprised of chains of monomers containing Silicon. These chains are formed by means of a polymerisation process during which the monomers bind together to develop a three-dimensional structure.
The main monomers use in the production of silicones are: dimethyl siloxane, triethylsilane, vinylsilane and hydrogensilane.
The silicone polymers available today can be divided into:
- 1st generation or condensation silicones
- 2nd generation or poly-addition silicones designed ad hoc for bio medical use.
CONDENSATION SILICONES
Condensation silicones are made by mixing a basic paste with a liquid that contains a tin-based hardener. Tin is a toxic element and can potentially cause irritation, allergies and systemic toxicity that can affect both the specialist and the patient.
During polymerisation by condensation the monomers combine together to form a disordered lattice. One consequence of the polymerisation reaction can be the formation of a secondary product that builds into blisters inside the product, creating weak points that can lead to fractures and compromise the physical-mechanical properties.
POLY-ADDITION SILICONES
Poly-addition silicones are obtained by mixing a paste containing basic silicone (vinylsilane) with a paste containing an addition silicone (hydrogensilane) and the hardener (organic platinum salt). The hardener used in these silicones, platinum, is one of the most stable and biocompatible elements available and therefore able to avoid the toxicity deriving from tin, used as a hardener in condensation silicones.
During polymerisation by poly-addition the monomers combine together to form an ordered lattice in which the monomers take up well defined positions without forming any by-products. This type of homogenous rigid structure ensures physical-mechanical properties that can be reproduced and are constant over time.
PODIKON SILICONES
Podikon products are silicones by poly-addition with an ordered, rigid and homogenous structure able to maintain the physical-mechanical properties of the medical orthosis over time.
The two silicone pastes (Base and Hardener) are packaged in convenient blisters that make them easy to use without any risk of material contamination while at the same time saving dispensing time. They are available in different levels of hardness and are used for the correction (Podikon 22) and protection (Podikon 35) of foot defects.
The product is shaped directly on the foot in order to customise as much as possible the solution provided. Vulcanisation or hardening takes place in just a few minutes and creates no discomfort at all for the patient.
