PROPERTIES OF 4 COMPOSITE VENEERING MATERIALS POLYMERIZED WITH DIFFERENT LABORATORY PHOTO-CURING UNITS

This study examined properties of four composite veneering materials p olymerized with two different photo-curing units for the purpose of ev aluating curing performance of the combination of composite material a nd curing unit. Two microfilled (Dentacolor(R) and Thermoresin LC II(R )) and two hybrid (Cesead II(R) and Solidex(R)) composite materials de signed for prosthetic veneer were selected. The respective light sourc es of the units were a xenon (Dentacolor XS(R)) and a metal halide (Hy per L II(R)) lamp. The composite materials were exposed with the photo -curing unit for 60 s on each side (i.e. from top and bottom). Knoop h ardness, compressive strength, flexural strength, flexural modulus, wa ter absorption and water solubility were determined according to stand ardized testing methods. The specimens exposed with the metal halide u nit generally exhibited greater Knoop hardness number, and compressive strength and lower solubility than those exposed with the xenon unit. A microfilled material (Thermoresin LC II) cured with the metal halid e unit exhibited significantly improved results for all tests as compa red with the same material cured with the xenon unit.