title: Development of a new poly(dimethylsiloxane) maxillofacial prosthetic material.
abstract: Maxillofacial prosthetic materials are used to rehabilitate patients suffering from acquired or congenital facial disfigurement. Silicone rubber materials [poly(dimethylsiloxane) rubbers] are the materials of choice. However, current formulations have inadequate mechanical properties, in particular, tear strength. The purpose of this study was to formulate a new poly(dimethylsiloxane) material with improved mechanical properties in comparison to commercially available materials. The formulations developed were based on condensation chemistry containing a hydroxy-end-blocked poly(dimethylsiloxane), hydrophobic silica filler, silane cross-linking agents, and a tin catalyst. The following parameters were varied in order to formulate improved materials: (a) bimodal polymeric mix (i.e., ratio of high- and low-molecular-weight polymers); (b) silica filler type and quantity. By varying these parameters a formulation was developed with a base polymer mix of 80%:20% high- to low-molecular-weight polymers into which 20% w/w filler was added. This formulation had a tear strength of 22.23 +/- 1.6 m N/mm compared to the commercial materials having tear strengths in the range 4.53-17.63 N/mm.
authors.affiliation: Departments of Dental Health and Biological Sciences, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Tariq
authors.initials: T
authors.lastname: Aziz
authors.forename: Mark
authors.initials: M
authors.lastname: Waters
authors.forename: Robert
authors.initials: R
authors.lastname: Jagger
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D004129:Dimethylpolysiloxanes / Q000138:chemical synthesis / Q000737:chemistry*; D019544:Equipment Failure Analysis; D006244:Hardness; D008422:Materials Testing; D019767:Maxillofacial Abnormalities / Q000534:rehabilitation*; D008447:Maxillofacial Prosthesis; D008970:Molecular Weight; D011474:Prosthesis Design; D012828:Silicones / Q000138:chemical synthesis / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D012828:Silicones; C013830:baysilon