Page 20 - Clinical relevance of current materials for cranial implants
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Chapter 1
Metals
For many years, metals have been used for cranioplasties. Booth and Gersten used aluminum and gold in 1890, Geib introduced vitallium in 1941, and tantalum was used by Pudenz and Odom (1942). In 1944, Boldrey discovered stainless steel mesh for cranial reconstructions followed by Scott, Wycic and Murtagh, who introduced a cranioplasty of stainless steel (1956). Thereafter, Simpson introduced titanium cranioplasties in 1965. Many other metals – or combinations – have been used, but most of them are replaced by stronger or better variants.18 Nowadays, pure metal cranioplasties are obsolete, except for titanium, mostly used as a mesh21. Titanium mesh is light-weighted, rigid, has a biological inertness, and resists infection. One of the main disadvantages of titanium is the cause of imaging artifacts and scattering, and it easily conducts heat and cold, which can be a clinical issue18,21. The rate of clinical (unwanted) exposure of the titanium mesh after reconstruction has been reported up to 42.2%21.
Poly (methyl methacrylate) (PMMA)
The German chemist Dr. Otto Rohm patented Plexiglas in 1933, which became very popular. It was used in submarine periscopes and airplane canopies during war. Acrylic was primarily a substance used by dentists17. The company Kulser (1936) introduced PMMA by mixing PMMA particles with a liquid monomer and benzoyl peroxide. After the dough stage, it was heated to 100°C and hardened in a stone mold22–24. This discovery led to the use of PMMA for the reconstruction of cranial defects in monkeys (1939). Zander was the first surgeon who inserted a two-stage methyl methacrylate cranioplasty into a patient in 1940. Followed by Spence (1954), who developed a one stage method for PMMA-reconstructions. Thereafter, during World War II, when the demand for cranioplasties was high, cranioplasties based on PMMA were frequently used.25





























































































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