Spectrophotometric evaluation of 5-layer acrylic teeth hyperpigmentation caused by selected food colors: In vitro study

Abstract

Background. Prosthetic treatment restores proper chewing function and facial aesthetics, and enhances the quality of life. The overall aesthetic result of the use of removable prostheses is correlated with the type of artificial teeth used and with the maintenance of aesthetic effect and color stability. Objectives. The aim of the study was to evaluate the formation and intensity of discoloration caused by the dyes present in selected 5-layer acrylic teeth. Material and methods. The study material was a group of 90 5-layer acrylic teeth. Samples were immersed in black tea and dry red wine for 6 months. The control group was immersed in distilled water and consisted of 30 samples. The teeth were subjected to spectrophotometric examination at the start of the study, after 24 h, 7 days, 14 days, 1 month, 4 months, and 6 months. Results. Among the teeth examined, in about 85% of the samples the color corresponded with the order. Teeth immersed in black tea became darker. From the 7th day to the 6th month, none of the samples changed their brightness. The teeth had the same degree of brightness. The teeth did not change tone during the experiment. Teeth immersed in dry red wine changed their shade to A starting on the 14th day, and by the 4th month all samples had changed shade to A or C. The 5-layer teeth had quite high shade stability until the 14th day of observation. In the control group, the teeth did not change tone and individual brightness changed more in the direction of brighter shades and less in the darker direction. In the study group, 93% of the samples did not change their brightness. Conclusions. Both black tea and dry red wine cause tooth discoloration, more intensely in the case of the 2nd fluid. Acrylic teeth with a 5-layer structure ensure good color stability over time. It improves the quality and aesthetics of the restorations used.