Researchers at the Vienna University of Technology have developed a new dental filling material which is easier to harden.
The researchers, in collaboration with dental manufacturer Ivoclar Vivadent, have developed photoactive materials based on germanium, which they say reduces the duration of the hardening process for fillings.
Modern dental composites contain photoactive organic resins which react to light of a particular wavelength and readily solidify. Professor Robert Liska from the University said: “Usually, light in the violet and ultraviolet region is used.” Light with longer wavelengths can also be used, which penetrates deeper into the material, but the polymerisation process is less efficient. If the filling cannot be hardened in one step, the procedure is repeated several times.
The newly developed composite contains 0.04 per cent of germanium. The researchers say that the molecule is split into two parts by blue light, creating radicals, which initiate a chain reaction: molecular compounds (which are already present in the filling) assemble into polymers, and the material hardens.
Tests showed that the penetration depth could be increased from two mm to four mm with the new compound.
Image: Initiator molecules are created in the synthetic chemistry lab at the Vienna University of Technology