BACKGROUND: The optical characteristics of ceramic dental restorations are of prime importance in esthetic rehabilitation. Lithium- disilicates are being widely used to create a full contoured restoration. Glazing and polishing are recommended to achieve a highly esthetic restoration. Dentists usually prescribe chemical plaque control agent, especially for those undergoing fixed prosthodontic procedures. There is lack of data about the effect of these chemical agents on the color stability of glass ceramics.
AIM OF THE STUDY: The objective of this laboratory study was to assess the effect of mouth rinses on the color stability of lithium-disilicate pressable glass ceramic.
MATERIALS AND METHODS: Twenty-eight disc-shaped specimens were fabricated using the heat pressing technique and then subjected to two different surface treatments: polishing and glazing (n=14 each). After that, specimens were immersed in two different types of mouth rinses: chlorhexidine (CHX) and Listerine (LST) (n=7 each). Color coordinates were measured using a digital spectrophotometer. Color differences (ΔE) were evaluated using CIE-LAB color system.
RESULTS: ΔE was affected significantly by the type of surface treatments and mouth rinses (P<0.001). All ΔE values were less than the selected acceptability threshold (ΔE=3.48). Glazed specimens (ΔE =0.95) were more resistant to discoloration than polished specimens (ΔE =1.61). The immersion in CHX (ΔE =1.44) showed more discoloration than the immersion in LST (ΔE =1.11).
CONCLUSION: The type of surface treatment significantly affects the color stability of lithium-disilicate pressable glass ceramics. The color stability of glass ceramics is improved by glazing. CHX mouth rinses must be used with cations.