History of Dental Implants
A look back through time…
Replacing teeth with an artificial analogue is not a new concept. In around 2500 BC the ancient Egyptians tried to prevent tooth loss with the use of wire made of gold. In about 500 BC the Etruscans tried to restore function with tooth replacements in the form of oxen bones. In 300 AD the Phoenicians used carved Ivory stabilised by gold wire to create fixed bridges. It was the Mayans in around 600 AD that used pieces of shells to replace teeth in the mandible. Interestingly, radiographic studies in the 1970s of these Mayan mandibles show bone formation around the implant shells, with a radiographic appearance similar to those of blade implants used centuries later.
In 1600s metal wire was used to stabilise teeth and in fact, teeth were collected from the underprivileged and transplanted into those more affluent in society. Dr John Hunter, a famous Scottish surgeon studied the anatomy of the mouth and jaws using cadaver studies (from bodies supplied by grave robbers). He proposed the use of transplantation of teeth, based on the implantation of an unformed tooth into the comb of a rooster. Amazingly the blood vessels of the comb grew into the pulp of the tooth. In the 1800s various materials were attempted including silver and iridium tubes to replicate teeth.
In the 1930s the Stock brothers used Vitallium, a cobalt chrome alloy, as the material of choice to replace a missing tooth. They are acknowledged for their work in the use of biocompatible materials. Fromaggion developed a post type implant placed within bone in the 1940s. The design of the implant, made from stainless steel in a spiral formation allowed bone to grow into the implant. This was developed further by Andres and then Chercheve by creating burs to allow a well-fitting implant within bone.
In the following decades subperiosteal implants, placed under the periosteum and on top of the bone, were proposed and developed, however, their success was limited. The blade implant by Linkow in the 1960s shows greater success as it was placed within the bone with a flat design differing from the post type design. Roberts and Roberts developed the Ramus Blade implant made of stainless steel to act as a third molar.
It was Bothe et al and Linde et al that demonstrated the fusion of bone to titanium in animal studies in the 40s and 50s. It wasn’t until the late 1970s that Professor Per Ingver Branemark, a Swedish anatomy professor presented the two-stage titanium root form implant (fixtures). In Toronto in 1982 Branemark presented his 15 years of retrospective research to critical acclaim within the scientific and dental community. In fact, the first implants were placed in patient Gosta Larsson in 1965 and lasted some 40 years until the patients passing in 2006. The patient was born with a malformed jaw and was orally disabled, however with the placement of dental implants and the fabrication of a prosthetic set of teeth the patent was able to eat and speak throughout his life. The use of titanium was a ‘by chance’ finding when conducting animal studies about blood flow in the femur of rabbits. Branemark noted the fusion of bone to titanium rods placed in the bone. The titanium rods which fused to the bone were difficult to remove. This fusion was defined by Branemark as Osseointegration and modern implant dentistry was developed from this point on. Branemark determines a sound set of implant protocols that were shown to be robust and safe with good long term results. The process of osseointegration took some 6 -12months and then prosthetic teeth were fabricated and the implants loaded. The prosthetics were of a certain design and treatment was carried out in what were lengthily procedures. The materials and processes have developed and it is now possible to extract a tooth and place an implant and prosthetic at the same time. It is predictable to have a reduced number of implants (four) retaining a fixed full-arch prosthetic (All on 4 registered trademark type treatment).