Which of the following is not a filler particle found in composite resin?

Composite resins are dental materials used for restorative procedures, and they typically consist of a resin matrix and filler particles. The filler particles play a crucial role in enhancing the mechanical properties, wear resistance, and aesthetic qualities of the composite material.

Quartz, silica, and barium glass are all common filler materials used in the formulation of composite resins. These fillers provide strength and stability to the resin while also influencing its optical properties to better match natural teeth.

Bis-GMA, on the other hand, stands for bisphenol A-glycidyl methacrylate. It is a resin monomer that forms part of the matrix in composite resins but does not serve as a filler particle. Its primary function is to provide the structural framework of the composite material, allowing it to bond with fillers and harden upon curing. This distinction is key to understanding the composition and function of composite resins in dental applications.