Implantología dental avanzada y estética facial. Advanced implantology & facial aesthetics. Dr. Pablo Furelos.
Several materials have been tested in order to be used for dental implants. But nowadays the only one accepted unanimously is titanium.
Let’s talk about some of the most interesting characteristics of titanium:
Although this information is just a summary, it seems to be complicated details. These characteristics show us the advantages and disadvantages of using titanium for dental implants:
We will try to explain this biocompatibility in a simple way. This metal has the capacity to perfectly integrate into the bone, as it has some characteristics other metals lack.
Our body has been designed to reject any strange element which could invade us and we have several methods to detect them. Firstly there are some proteins that are foreign to our body which are quickly eliminated. This allows us to be protected against bacteria and viruses, but it is also responsible for the rejection of grafts from other people. Secondly, metallic ions produce some modifications in our proteins, which lead to a defensive response and the ejections of the metallic agent.
When materials come in contact with biological fluids, they capture the oxygen and then oxidize, going through a process of ionization. By this process the external atomic layer goes through some changes that affect its union to the next atomic layer, which gets oxidized as well, releasing more ionized material. Those ions are unstable. In order to re-establish its stability they join the guest’s proteins, creating a metal-protein that is erroneously recognised by the organism as an invasive antigen (bacterium or virus). This triggers a reaction of the immunologic system. Lymphocytes multiply to fight the supposed to be invader.
The so called stainless steel, which also oxidizes, consists on iron, 14% nickel, 18% chrome, 2% manganese and 3% molybdenum. There are too many ions.
Titanium doesn´t go through this process; its first layer oxidizes but its union to the second layer of atoms that remains stable. This means no ionized atom is detached, so it is invisible to our biological defence systems. Tissues, as for example bones, repair their wounds without perceiving the aggressor and establishing a solid union with this invisible object. Such a lucky fact allows human beings to use this metal for several medical purposes, as for example dental implants.
That is why the term rejection is not suitable, because the human body has no capacity to reject something that cannot be detected.
All in all titanium is a biocompatible metal, as its presence is tolerated by tissues without producing an allergic reaction of the immune system. Besides this characteristic, its hardness, lightness and resistance have made its multiple medical uses possible, not only for dental implants but also for hip and knee prosthesis, bone screws, anti-trauma plates, components of heart valves and pacemakers, glasses, surgical instruments or even piercings.