Page 25 - Clinical relevance of current materials for cranial implants

General introduction and outline of this thesis
Various areas in healthcare use PMMA: orthopedics, dentists, maxillofacial surgery 1 and neurosurgery. PMMA is cost efficient, radiolucent, light and easy to use. PMMA
is formed through the polymerization of liquid methyl methacrylate (MMA) using
PMMA powder as a filler to minimize shrinkage. Unreacted MMA (residual monomers)
remains in the final product. However, the precise concentrations are still unknown for all PMMA-based materials. In Chapter 8, the amount of released, non-polymerized, monomers (residual monomers) is analyzed in four different PMMA-based materials with different compositions and fabrication methods (Vertex Self-Curing, Palacos R + G, DePuy CMW-3, and NextDent C&B MFH).
To reduce surgical time during polymerization the medical device may be manufactured before surgery with use of 3D imaging and additive manufacturing techniques. However, the created cranial implant still needs to be sterilized. This presents a challenge to assure optimal material behavior. Hence, in Chapter 9, four different sterilization methods (ethylene oxide, hydrogen peroxide plasma gas, autoclavation, and gamma-irradiation) are used for the sterilization of three different types of PMMA-based materials (Vertex Self-Curing, Palacos R + G and NextDent C&B MFH). To study the mechanical properties, the flexural strength, flexural modulus and impact strength were measured.
Part V General discussion
The overall findings of this thesis are presented in Chapter 10, in which the main results are summarized and discussed, followed by a description of the future perspectives.
Summaries of this thesis are presented in Chapter 11 in English and Dutch, respectively.
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