Objective: Mouthwashes containing chlorhexidine can cause discoloration in restorative materials when used for the long-term. To prevent staining of a restorative material, several protective materials are used. The aim of this in vitro study was to evaluate the impact of a surface sealant on the color stability of a nano-hybrid composite resin material immersed in different mouthwashes.
Methods: A total of 42 composite resin discs (10 x 2 mm) were prepared with a nano-hybrid composite resin (Herculite XRV Ultra) using Teflon moulds. The composite specimens were first divided into two groups (with or without a surface sealant) then into three subgroups (n = 7) according to the mouthwashes (Gengigel, Oderol, and Klorhex). After SS application to 21 specimens, all the discs were subjected to baseline color measurements using a spectrophotometer according to the CIE L*a*b* system. The specimens underwent thermal cycling. Following immersion in different mouthwashes for 24 hours, the color measurements were repeated. The ΔE data were assessed using Kruskal-Wallis one-way ANOVA. Mann-Whitney U test was performed for different immersion mouthwashes (p<0.05).
Results: Statistically significant differences (p<0.05) were found between the unsealed composite specimens immersed in Klorhex and the other mouthwashes in terms of ΔE values. The Klorhex appeared to be associated with the most severe alteration in color (5.14±0.83), followed by Gengigel (2.21±1.46) and Oderol (1.94±1.75). There were no statistically significant differences (p>0.05) between the sealed and unsealed composite specimens in terms of the color changes.
Conclusion: The application of a low viscosity liquid surface sealant material did not show the expected effect on the color stability of a nano-hybrid composite resin in terms of three different mouthwashes.
Keywords: Color change, mouthwash, surface sealant, composite resin, thermal cycling