Stainability of different ceramic materials against mouth rinses and effect of polishing after staining

Mouth rinses are known to stain tooth surfaces. However, their staining effect on different ceramics after prolonged use and the effect of polishing after staining are still unclear.

The purpose of this in vitro study was to evaluate the stainability of different ceramic materials against different mouth rinses and the effect of polishing on staining.

Forty disk-shaped specimens were prepared from each material (total of 160 specimens): lithium disilicate (IPS e.max CAD), zirconia-reinforced lithium disilicate (VITA SUPRINITY PC), leucite-reinforced feldspar (GC Initial LRF), and resin matrix ceramic (CERASMART). Baseline color measurements (T0) were recorded with a clinical spectrophotometer (VITA Easyshade V). The specimens were immersed in chlorhexidine gluconate (CHX) 0.2% mouth rinse (Klorhex), (KLO) chlorhexidine gluconate 0.1% mouth rinse (Eludril) (ELU), a daily mouth rinse (LISTERINE Cool Mint) (LIS), artificial saliva (CON) continuously for 7 days (T1), 14 days (T2), and 28 days (T3). Discoloration values (ΔE) between the immersion time points (T0,T1,T2,T3) were calculated by using the following formula: ΔE= ([ΔL∗]² + [Δa∗]² + [Δb∗]²)^1/2. After the immersion process, specimens were polished and ΔE values remeasured. The Kruskal-Wallis and Mann-Whitney U tests were performed (α=.05) and were adjusted by postanalysis Bonferroni testing.

KLO caused the highest ΔE values in all groups. IPS e.max CAD had the lowest ΔE values, and CERASMART showed the highest ΔE values against all of the solutions (P<.05). However, polishing caused a decrease in the ΔE values in all groups.

Prolonged use of mouth rinses may cause color change in different ceramic materials. Polishing affected the color change and resulted in a decrease in ΔE values. Mouth rinses containing CHX should be recommended with caution for daily use.