Development of a new poly(dimethylsiloxane) maxillofacial prosthetic material

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Medical Device Development

Background:

• Maxillofacial prosthetics address facial disfigurement from trauma or congenital conditions.
• Poly(dimethylsiloxane) (PDMS) rubbers are preferred for facial prostheses due to their biocompatibility and aesthetics.
• Current PDMS materials exhibit insufficient mechanical properties, particularly low tear strength, limiting their durability and performance.

Purpose of the Study:

• To formulate a novel poly(dimethylsiloxane) material with superior mechanical properties, focusing on enhanced tear strength.
• To compare the performance of the new PDMS formulation against existing commercial maxillofacial prosthetic materials.

Main Methods:

• Formulation of PDMS materials using condensation chemistry.
• Incorporation of hydroxy-end-blocked PDMS, hydrophobic silica filler, silane cross-linking agents, and a tin catalyst.
• Systematic variation of formulation parameters: bimodal polymer mix ratios (high- vs. low-molecular-weight PDMS) and silica filler type/concentration.

Main Results:

• A specific formulation achieved a tear strength of 22.23 +/- 1.6 mN/mm.
• This represents a significant improvement over commercial materials, which exhibit tear strengths ranging from 4.53 to 17.63 mN/mm.
• The optimal formulation utilized an 80%:20% ratio of high- to low-molecular-weight polymers with 20% w/w silica filler.

Conclusions:

• The developed PDMS formulation demonstrates significantly improved tear strength compared to current commercial options.
• This advancement holds promise for creating more durable and resilient maxillofacial prosthetic devices.
• Optimizing polymer blend ratios and filler content is crucial for enhancing the mechanical performance of PDMS-based maxillofacial materials.