RESIN
The term “silorane” was introduced to represent hybrid monomer systems that contain both siloxane and oxirane structural moieties. Concerning the material properties of siloranes, the cyclosiloxane backbone imparts hydrophobicity while the cycloaliphatic oxirane sites have high reactivity and shrink less during polymerization than methacrylates . some cyclosiloxanes have been reported to undergo cationic ringopening polymerization with volume expansion. Marginal integrity and microleakage of silorane-based restorative systems are reported to be superior to methacrylate-based systems.
INTIATING SYATEM
The development of a photoactivated silorane composite was realized with a three component initiating system comprising camphor quinone an iodonium salt and an electron donor. camphor quinone was chosen as a photo initiator to match the emission spectra of the currently used dental lamps. In this reaction path the electron donor acts in a redox process and decomposes the iodonium salt to an acidic cation which starts the ring opening polymerization process.
FILLER
Quartz particle of 0.5 micro meter has been used.
Commercially available as P90 ( 3M ESPE )
REF: Dental materials ( 2007 )23, 1011–1017
Dental Materials (2005) 21, 68 -74
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