Dental Implant
A dental implant is an artificial tooth root replacement and is used in prosthetic
dentistry. There are several types. The most widely accepted and successful is the
osseointegrated implant, based on the discovery by Swedish Professor Per-Ingvar
Branemark that titanium could be successfully incorporated into bone when osteoblasts
grow on and into the rough surface of the implanted titanium. This forms a structural
and functional connection between the living bone and the implant. A variation on
the implant procedure is the implant-supported bridge, or implant-supported denture.
A typical implant consists of a titanium screw, with a roughened surface. This surface
is treated either by plasma spraying, etching or sandblasting to increase the integration
potential of the implant. At edentulous (without teeth) jaw sites, a pilot hole
is bored into the recipient bone, taking care to avoid vital structures (in particular
the inferior alveolar nerve within the mandible). This pilot hole is then expanded
by using progressively wider drills. Care is taken not to damage the osteoblast
cells by overheating. A cooling saline spray keeps the temperature of the bone to
below 47 degrees Celsius (approximately 117 degrees Fahrenheit). The implant screw
can be self-tapping, and is screwed into place at a precise torque so as not to
overload the surrounding bone. Once in the bone, a cover screw is placed and the
operation site is allowed to heal for a few months for integration to occur. After
some months the implant is uncovered and a healing abutment and temporary crown
is placed onto the implant. This encourages the gum to grow in the right scalloped
shape to approximate a natural tooth's gums and allows assessment of the final aesthetics
of the restored tooth. Once this has occurred a permanent crown will be constructed
and placed on the implant. An increasingly common strategy to preserve bone and
reduce treatment times includes the placement of a dental implant into a recent
extraction site. In addition, immediate loading is becoming more common as success
rates for this procedure are now acceptable. This can cut months off the treatment
time and in some cases a prosthetic tooth can be attached to the implants at the
same time as the surgery to place the dental implants.