Effect of caries infiltration technique and fluoride therapy on the colour masking of white spot lesions

Objectives: A carious lesion is initiated through the subsurface demineralization of enamel, and presents clinically as a white spot, interfering with the aesthetics. This lesion should not receive restorative treatment because it is capable of remineralization. The aim of this study was to evaluate the performance of different treatments on masking white spot lesions by assessing the colour change. Methods: Artificial white spot lesions were produced in bovine enamel of 60 cylindrical-shaped samples. The samples were randomly divided into four groups: CON (control) immersion in artificial saliva; DF - daily application of 0.05% fluoride solution; WF - weekly application of 2% fluoride gel; and IC - resin infiltration (Icon (R) - DMG). The assessment of colour was performed by a spectrophotometer in four distinct stages: baseline, after the production of artificial caries; after 4 weeks; after 8 weeks; and after a new acid challenge. The Delta L values were calculated at each stage in relation to the baseline colour. Results: The application of RM ANOVA revealed significant differences between the factors' treatment and time (p = 0.001). For the interaction between factors there were no significant differences (p = 0.27). The Tukey's test (p < 0.05) was then applied and showed that the specimens treated with Icon (R) exhibited the lowest means, followed by Group DF, Group CON, and Group WF, in that order. Conclusion: Resin infiltration was proven to be an effective treatment for masking white spot lesions. Also, after a new acid challenge, the group infiltrated with low viscosity resin presented the lowest means of colour change. (C) 2011 Published by Elsevier Ltd.