A study on the discoloration of different dental porcelain systems

Purpose: This study aimed to investigate the discoloration of four types of dental porcelain systems (feldspathic, monolithic zirconia, lithium disilicate, and leucite glassceramic) with various surface treatments (glazed and mechanically polished) after undergoing chewing simulation against a natural tooth antagonist. Materials and methods: Disc-shaped porcelain groups (9x3mm) were produced for the following categories: feldspathic glazed (FG), feldspathic mechanically polished (FM), zirconia glazed (ZG), zirconia mechanically polished (ZM), lithium disilicate glazed (ExG), lithium disilicate mechanically polished (ExM), leucite glass-ceramic glazed (EG), and leucite glass-ceramic (EM). In vitro chewing simulation was conducted on all porcelain groups, and a spectrophotometer was used to compare the color changes between their initial states. Results: The ΔE values (discoloration) of all porcelain samples were statistically different (p <0.05), and the ΔE values of the glazed samples were higher than those of the mechanically polished samples. Conclusion: All the glazed samples are more likely to show more color change than the mechanically polished sample groups.