Implant – a foreign body, so implantation can be a problem: how to find such an alloy which would not react with the surrounding tissues, is not oxidized, and most importantly, not reject them. In addition, each body reacts differently to the same thing, that is something that is safe for one person may have a negative impact on another. With prosthetics Wednesday mouth is very aggressive. On aids and prostheses affects a range of chemical, physical and biological factors. Not remain passive and synthetic materials – they also affect the teeth, mucosa, and the entire human body as a whole. CBS might disagree with that approach. How does it done? Food and saliva are none other than the chemically active electrolyte. When the mouth is a seal or a metal prosthesis, it becomes a cause galvanic cell, which generates a galvanic current.
It occurs usually during the electrochemical corrosion of alloys or metals, and the higher acidity of saliva, the greater the value electromotive force of galvanic cell. This phenomenon can cause and corrosion-resistant materials, but have different electrical or electrochemical potential. That’s why not all the alloys, used for the manufacture of dental prostheses are compatible with each other. Patients then begin to complain about the burning of the mucous membrane, discomfort, metallic taste and bad breath. In the process occurring in the oral cavity of complex chemical reactions, and sometimes can form harmful for the body material. In addition, some materials may cause negative shifts in fluids and tissues, to influence acidity, changing the microflora of oral cavity, break sensitivity, blood circulation and cause inflammation.
Unfortunately, even today, used in prosthetic dentistry base alloy can not claim on entirely inert to corrosion. Therefore it is necessary to cover the metal parts of prostheses with a protective layer of nitrite titanium, gold and other similar inert alloys. High chemical resistance are based alloys gold, palladium, platinum, stainless steel, acrylic plastic, and, finally, porcelain. This is because they are always wrapped in the thinnest oxide film, which protects the metal from further oxidation. So, to summarize. Materials for dental prostheses must meet the following requirements: be chemically inert and harmless; have sufficient resistance to the power of influence, have to be mechanically strong, to keep constancy of volume and shape. This should also add a good technological features (otherwise it is impossible to conduct molding, stamping, molding would nullify all the previous virtues). Well, of course, the materials to prosthetics, which are difficult to hide under a smile or conversation, the color should be close to the enamel, and it is their property they need to maintain a sufficiently long time.