Meaning Of Dental implant
A dental implant (from Latin in " in , inside " and planta " Cutting Seedling " ) [1 ] is inserted into the jawbone alloplastic assembly part (implant ) . The concerned branch of dentistry that deals with the insertion ( insertion ) of dental implants into the jaw bone is called as implantology (from Greek λόγος lógos , word ' teaching ') . Due to their utility as carriers of dentures dental implants take over the function of artificial tooth roots. For this purpose they are using either screw into the jaw bone ( endosseous [2 ] implants) screwed or plugged . They combine within 3 to 6 months with the surrounding bone to a solid, highly stress-resistant carrier unit ( osseointegration ) .
From the implant shape the surgical insertion technique depends. From the shape of the abutment, the protruding from the jawbone implant part, results in the production of the superstructure, the resettling on the implants tooth replacement. Dental implants have existed since the 1980s, usually made of titanium, but also from ceramic materials.
Titanium implants:
After long decades with different , today part naïvely implant designs from before the war , is rotationally symmetrical implants (usually screw implants ) enforced. In these implants , the implant body in cross-section is circular , so that the implant cavity , the cavity that will hold the implant , can be prepared with rotary instruments , such as a gun drill into the jawbone . The screw implants differ mainly in their taper and in the type of thread.
This surgical approach stresses the patient less than earlier implantation
techniques , and very rarely leads to complications in wound healing. In
addition, screw implants have the advantage that they are distinguished by
their thread in the bone immediately " fix " (primary stability).
This shortens the healing time because very little bone " regrow "
must . In some of the implants , the basic cylindrical shapes tapered apically
, toward the end , so that overall a cone shape.
In contrast to orthopedics, mainly titanium alloys are used in the , dental
implants are made of pure titanium. Titanium has a high biocompatibility that
does not cause allergic or foreign body reactions . Titanium is in contrast to
other materials, a direct molecular connection with the bone . Here plays the
rough, morphological surface design with a micro - pore average depth of 5 to
100 microns a key role. Initially it by spraying ( " additive method
" ) of titanium powder was added under argon and high temperature reached
( titanium plasma - spray " TPS "). [3 ] This process is relatively
expensive, so many manufacturers since about the year 2000 to the cheaper acid
etching process ( "acid etching" or combinations thereof "
SLA" called ) to fall back by a mixture of hydrochloric acid and sulfuric
acid ( " subtractive method "), which faces the additive method
equivalent or even superior.
The property of the titanium to form a protective oxide layer with oxygen on
the surface , is the cause of its particularly good compatibility . Both
methods have a high success rate (over 95 % for a five-year retention period )
. Implants must have a certification from the health authorities as a safe
medical devices ( CE or FDA approval ) . Exceptions are made according to the
Medical Device Directive (MDD ) for individual implants , which are made for a
single patient when prescribed by a dentist.
Metal -based crowns:
The
metal-based crown can be made from a
high grade gold alloy, a reduced gold alloy , titanium or a base-metal alloy (
NEM) . At the cheaper reduced gold alloys can occur under certain circumstances
to allergies or discoloration of the oral mucosa by the admixture of less noble
metals such as palladium. Therefore, one used today in addition to the
expensive " high gold " alloys and non- precious alloys , precious
metal alloys or titanium biocompatible as a cheap alternative .
The metal-based crowns have the unfaced full cast crowns , partially veneered
crowns and fully veneered crowns are made . The veneering material can be either a veneer
resin on composite basis (ie, a mixture of a resin matrix and ceramic fillers )
or ceramic be ( veneering metal-ceramic : VMK ) . The latter require because of
the high baking- ( 800-900 ° C) special ceramic alloys that form an
adhesion-promoting layer of oxide during the firing process . The porcelain
veneer is more complex , but has told the plastic veneer the aesthetic
advantage of better color stability and increased abrasion resistance .
However, this can also be a disadvantage because their extreme hardness
prevents a uniform abrasion ( grinding natural ) and the antagonist ( opposing
teeth) " bitten " disproportionately.
All-ceramic crowns:
All-ceramic crowns have taken the metal skeleton usually a core which is then overburned. The core may be on a CNC drilling and milling machine to mill made of zirconia, and then are veneered with ceramic. There is also the possibility of pressing at high temperature from the liquid ceramic crown exclusively of ceramics (ceramic press). In this case, a further blending is not absolutely necessary, but provides advantages for the production of translucency and opalescence. Thus, a natural color effect modeled werden.Vollkeramikkronen cause by a lower thermal conductivity less thermal stimuli.
Referance By:-
http://de.wikipedia.org/wiki/Zahnimplantat