Visible light photopolymerization of triethyleneglycol dimethacrylate (TEGDMA)initiated by camphorquinone(CQ) and peroxide (PO) combination systems were studied with photocalorimetry for the purpose on dental materials. As comparison with CQ alone

the systems composed of CQ and peroxides PO are more effective. The results obtained indicated that the peroxide added

such as dicumyl peroxide (DCPO)

di tertbutylperoxide(DBPO) greatly accelerates the polymerization rate( R p) and shortens the time of R maxp reached(tmax)

however their corresponding hydroperoxide

such as tert-butylhydroperoxide(TBPO) and cumyl-hydroperoxide(CHHP) appears a less efficient.The reaction mechanism of the synergistic effect for CQ/PO system was suggested to be a energy transfer process from excited CQ* to peroxide

which results in a significant facilitation of the active radical generation from peroxide.The rate-enhancement of polymerization was also found in the presence of oxygen.