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Early Historical
Developments:
Replacing lost teeth
with a “bone anchored device” is not a new
concept at all. Archeological evidence was
found that the ancient Egyptian and South
American civilizations already experimented with
“re-implanting” lost teeth with hand-shaped
ivory substitutes.
In the 18th
century lost teeth were sometimes replaced with
extracted teeth of other “donors”. The
implantation process was probably somewhat crude
and the success rates extremely low due to the
strong immune reaction of the receiving
individual.
In 1809, Maggiolo
fabricated a gold “implant” which was placed
into fresh extraction sockets to which he
attached a tooth after a certain healing period.
In 1887, a physician named Harris tried the same
procedure with a platinum post, instead of gold;
and in 1886 Edmunds was the first to implant a
porcelain crown mounted on a platinum disc in
the US at the First District Dental Society of
New York. Several other attempts were made
along the same line, experimenting with
different metal alloys and porcelain
formulations, however on the whole the long-term
success rates were very poor.
Strock placed the
first somewhat successful oral implants in 1937
at Harvard University. Strock published a
paper on the physiological effects of
cobalt-chromium-molybdenum alloy (vitallium) in
bone, and thus placed a series of vitallium
implants into test animals and humans.
These implants were immediately implanted after
an extraction and no untoward post-operative
complications were reactions were recorded.
Histologic sections from the test animals showed
remarkable, complete toleration. He
followed some of his patients successfully for
fifteen years, until he died. Certain
types of implants used today are often still
cast from vitallium.
Modern Historical
Developments:
The time span from
the mid-1930s to the present represents the
period one begins to see the emergence of
implant concepts developed into those that are
presently the most refined and popularly
utilized. These methods include the
Subperiosteal, the
Endosteal Blade, the
Ramus Frame and the
Endosteal Root-form or Cylindrical Implant.
The Subperiosteal
Implant has been successful in treatment during
the past 30 years according to several
publications. The first Subperiosteal
Implant was placed in 1948 by Gustav Dahl and
was constantly improved in its design since
then.
The Endosteal Blade
Implant, introduced independently in 1967 by
Leonard Linkow and Ralph and Harold Roberts also
proved to be a very viable form of patient care
with respect to implant reconstruction.
The quantum leap in
Implant Dentistry was achieved in 1952 in the
Laboratory of Vital Microscopy at the University
of Lund, Sweden, by a Swedish research team
headed by
Per Ingvar
Branemark, an Orthopedic Surgeon.
One of their research projects was to study the
microscopic “healing events” in bone.
Their test subjects were rabbits. Dr.
Branemark’s team designed an optical chamber
housed in a titanium metal cylinder, which was
screwed into the rabbit’s thighbone. Once
the experiment was completed after several
months, they realized that the titanium cylinder
had “fused” to the bone. He named this
phenomenon Osseointegration. Based on this
observation, Dr. Branemark’s research shifted
more towards the use of titanium appliances in
human bone, including the use of titanium screws
as bone anchors for lost teeth. Many
experiments and trials by himself and colleagues
from other disciplines and institutions would
head in that direction providing adjunctive
expertise in physics, chemistry, biomechanics,
medicine and physiology. The
Osseointegration concept evolved closely coupled
with the design of a cylindrical titanium screw
with a specific surface treatment to enhance its
bioacceptance. |