Filtek? P60 restorative material is a visible light-activated, radiopaque, restorative composite designed for use in posterior restorations. According to the manufacturer��s instructions, Filtek? P60 composite resin material is indicated for use in indirect restorations including inlays, onlays and veneers. Thus, in the current study we polymerized selleckchem Crizotinib this composite resin material in inlay and light sources followed by additional time in an autoclave. Light sources have been used to convert the composite, and have been investigated whether there is a correlation between the intensity of light source, time of exposure, types of material, and distance from the tooth to the curing source.28 Light-sensitive materials contain camphorquinone (CQ) to react with a reducing agent when activated, and activating it to polymerization requires sufficient light intensity and a suitable wavelength.
29 CQ significantly influences the color of the material30 as it is a yellow chemical compound. During light irradiation at 478nm wavelength, it changes color and becomes colorless. However, if irradiation is not enough, a certain amount of yellow will remain.31 In the present study, specimens polymerized with different polymerization units revealed a color shift from yellow to blue (��b*<0) and from red to green (��a*<0) after polymerization. All specimens became darker during investigation (��L*<0). The same phenomenon, in term as decrease in b* value after resin composite polymerization was also reported by Sidhu et al.
32 It is well known that inadequate polymerization adversely affects the mechanical properties of composite materials in terms of strength, color stability,29 hardness,12 and wear resistance.33 When post-polymerization methods are used, material properties can be improved.14 Post-cure heating of resin composite materials has become a very popular restorative technique.34 Many properties enhanced by post-cure heating, such as fracture toughness, flexural modulus, and flexural strength, were found to decrease to levels identical to those of the light-cured-only group35 when the specimens were subjected to water storage after curing. The various methods of post-curing (light, heat, pressure, vacuum, and nitrogen) allow for secondary curing of the composite by increasing the conversion of the resin material from monomer to polymer.
36 In their research, Silva et al37 used different laboratory photo curing units and conventional halogen light sources followed by additional in an autoclave. They reported that the use of light curing in conjunction with heat and pressure curing improved the mechanical properties of resin composites and the use of alternative polymerization Carfilzomib with conventional photo curing; the autoclave was shown to be feasible, with a wide implication for the general public in terms of reduced dental treatment cost.