Effects of mouthrinses on discoloration of CAD-CAM manufactured restorative materials

To investigate the in vitro effect of four different mouthrinses on discoloration of popular CAD-CAM blocks.

40 specimens were prepared and then were divided into five groups (n = 8) for each CAD-CAM block (Vitablocks Mark II, IPS e-max CAD, GC LRF, Enamic, Cerasmart). In total, four different mouthrinses for each group (Listerine Zero, Parodontax, Kloroben, Oral B Pro-Expert) and distilled water for the control group were used. The specimens were immersed in 20 ml solution for 2 minutes, twice a day for 21 days with a 12-hour interval. Color changes were measured with a digital spectrophotometer (Vita Easyshade) after 7, 14 and 21 days and specimens were prepared. For statistical analysis, color changes ( ΔE) were calculated and Kruskal Wallis and Wilcoxon tests were used.

There was not a significant difference in ΔE1 and ΔE2 values (P> 0.005) while there was a significant one in ΔE3 (P= 0.001) after Bonferroni correction for CAD-CAM materials were carried out as it is independent of the mouthrinse. Listerine Zero brought about the most noticeable color change in all CAD-CAM materials except e.Max after 21 days.

Discoloration effect of the tested mouthrinses on various CAD-CAM materials was different depending on the usage period. However, these differences did not exceed the clinically perceptible values.