system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Resin matrix system used in the composite shown below is:
assistant
The correct answer is  Polyhedral Oligomeric Silsesquioxane (POSS):
POSS molecules are 12-sided silicate cages produced from silane and functionalized to copolymerize with other monomers.
POSS is a molecule-sized hybrid organic-inorganic oligomeric compound that can disperse homogeneously in compatible monomers and become covalently incorporated into cross-linked networks upon curing. Like the ormocer-type materials, the silicate cage structures provide a reinforcing function, but filler particles must also be included to achieve the balance of mechanical and other properties required for adequate performance as dental composites.
Reference-Phillips’ Science of Dental Materials / Kenneth J. Anusavice - 11th Ed Pg:303