Here are the
different types of materials used in dental implants.
Alloys
When you are in the presence of an alloy that contains only two metals such as
silver (Ag)-tin (Sn) and copper (Cu)-tin (Sn), tin produces a film of oxidation
on the surface of the alloy and confers an inertia that protects it from
corrosion in the middle of the living tissue. This is equally true in the case
of alloys of chromium (Cr)-cobalt (Co) and nickel (Ni)-chromium (Cr). When a
small amount of chromium is mixed with cobalt and nickel, its toxicity is
entirely masked by chromium and can be verified on the contrary an excellent
adhesion with the tissue around it as it creates a state of inertia on the
surface of the alloy for the film oxidized chromium homogeneous.
Stainless steel
The alloy of chromium (Cr), nickel (Ni)-iron (Fe) has been primarily used in
orthopedic surgery. Depending on the signs, he adds a certain amount of
molybdenum (Mo), carbon (C) or tungsten (W), to improve its mechanical
properties. One can distinguish two groups:
The type iron (Fe)-chromium (Cr)-carbon (C), has magnetic properties and good
mechanical properties, but it corrodes easily in the body.
Of the group chromium (Cr) 18, nickel (Ni) 8, iron (Fe), is often added
tungsten or molybdenum, this group is not magnetic, is stable in the body and
do not corrode easily.
What Are Dental
implant materials?
Because dental implants are made of different materials that are placed in the
jawbone of the patient, to replace the roots of teeth and will not cease to be
an artificial root that replaces the natural tooth that has been lost, it is
important to avoid situations of rejection and toxicity of such materials.
For example, pure metals with the cellular toxicity tests has shown that
beryllium (Be), magnesium (Mg), calcium (Ca), cadmium (Cd), strontium (Sr),
barium (Ba ), Zinc (Zn) and mercury (Hg), have a strong toxicity, while the
aluminum (Al), the Indus (In) and gallium (Ga) not accuse any toxicity.
Cobalt-chromium alloy
From the moment that has been used during the addition of phosphate mergers,
the method of casting of the alloy chromium (Cr)-cobalt (Co) has been
considerably simplified. Today, these alloys have gained greater security and
are therefore widely used as material for implants. In 1924, Zierold employee
and as an alloy implant material that was broadcast in 1937 by Venable. Under
the name of Vitallium, was also used in orthopedic surgery restorer.
In numerous studies have shown that, while the cobalt could only be cytotoxic,
from when it was combined with some well-defined metal alloy behaved as an inert
and nontoxic. Thus, the toxicity of cobalt is neutralized by the presence of
chromium and disappears. However, this does not occur only from the time that
the alloy containing more than 40% chromium.
Titanium
Research on these materials have significantly insisted on its compatibility
with human cells, physiological state that the inertia of titanium is due to
not cause any electrolytic corrosion and its ionization is negligible to the
point that in any case their ions can attack the tissue surrounding it. Based
on the metal powder that is compressed, then melted in a vacuum, you get a high
strength and high porosity. This porosity can be shaped depending on the
fineness of the powder used. With this constitution porous materials acquire
qualities of integration. Note that the titanium has also been used as a metal
addiction to strengthen the mechanical strength of the alloy cobalt (Co)-chromium
(Cr) and stainless steel.
Biomaterial
The use of porous metal has attracted many researchers who wanted to insert
into the so-called tissue biomaterial. Using dental implants for bone-metal
union seems to operate well, the cellular elements are inserted into the porous
matrix as if bee nests. The porous material creates an airtight catalysis
making the intent of the first around the implant that is continued on the
other hand, in the future. This connective tissue is developed inside the pores
of the material, creating in some way at some sort of equivalent neck
ligaments.
Polyethylene
Although this material can not be used at room temperature, on the contrary
shows a good stability and has been widely used because of its flexibility and
high resistance to friction. He was often used in cranio-facial
reconstructions, where he has been very successful. In general, polyethylene is
polymerized at high temperature and pressure, but has recently been introduced
a new form of radiation polymerization at low temperature. Thanks to its high
resistance to breaking and its high flexibility, is particularly in regions
experiencing strong pressure. This material can be cut with a chisel, is a weak
weight, little thermal conductor and has a low solubility rate in the body.
Ceramics
Implant has been used in the A1203, in form of mono or polycrystals, or even of
the apatite obtained from bovine bone or even the synthetic apatite. Most
authors describe the bio-ceramic material implantable, insisting on its inertia
and lack of toxicity. However, when the pores, rather than set at 100 microns
reach 150 or 200, there are remnants of the degradation at the surface of
calcium aluminate after 22 weeks
Plastics
These are substances that remain in a long time means hot and humid, which
absorb water in their organic environment, changing its structure and
degenerate. As the polymers are not toxic, it is necessary that the resin is
free of any residual monomer. The toxicity of the monomer is so important, yet
it dissolves blood clots and tissue fragments. Silicones and polyethylene have
been used in plastic surgery, are not irritant and are not very hydrophilic.
You could say that in general, highly polymerized materials show almost no
toxicity and irritating properties but could pose problems after 5 or 10 years.
Silicone Rubber is very stable, as might be whether implant material can not
provide a very weak binding to the tissues surrounding it.
