Abstract
Purpose: Composite denture teeth have superior physical properties to acrylic resin teeth in terms of greater hardness and abrasive resistance. However, surface staining is still a major problems associated with composite denture teeth. The purpose of this study was to clarify the relation between surface roughness and surface staining of artificial teeth.
Materials and Methods: Three different composite denture teeth and two acrylic denture teeth were evaluated. Each artificial tooth was placed on a paraffin wax block. Half of the specimens were formed using a gas torch, and the others were not formed using a gas torch. Then, investing, packing and processing heat curing resin was carried out. After cooling, the specimens were polished with rough brush-polishing, soft brush-polishing and buff-polishing with a laboratory lathe. A control group consisting of five teeth was placed on self-curing resin without polishing. The roughness values (Ra and RzJIS) of each specimen were measured using a laser microscope. The color difference values (ΔE*ab) of specimens were measured before and after immersion in tea solution for seven days using a spectrophotometer. The roughness value data were statistically analyzed by Dunnett's test, and t's test for a comparison between forming and not forming. Color difference data were similarly analyzed by Dunnett's test and t's test. Color difference values were analyzed by Tukey's HSD test as a comparison between different artificial teeth.
Results: Each of the artificial teeth showed various changes in Ra and RzJis with polishing, but it could not be established how far polishing influences the roughness values of artificial teeth. There was no significant difference in the color difference values by polishing and burning, except for one composite denture tooth.
Conclusion: Within the limitations of this study, polishing and forming using a gas torch have no effect on the staining of composite denture teeth.
