BACKGROUND AND OBJECTIVE: The impact of external factors on color of ionomer glass as a restorative material is important due to its beauty. The aim of this study was to evaluate discoloration of conventional and resin-modified ionomer glass, after the application of fluoride varnish.

METHODS: In this study, 16 samples of each ionomer glass Chemfil Superior (C) and (F) Fuji II LC were prepared. Then fluoride varnish Dura shield (Sultan, USA) was used on samples (Cf, Ff). The color of each sample was measured using a spectrophotometer (Gretage Macbeth, Color-eye7000A) and digital camera (Sony Cyber-shot DSC N1) before and after the application of fluoride varnish. Obtained data from camera was converted to color space Lab CIE by MATLAB software. Discoloration (ΔE) of each sample was calculated in spectrophotometer and digital camera and statistical analysis was performed.

FINDINGS: Using spectrophotometer ΔE in Cf and Ff groups was obtained 4.44 and 5.8, respectively, but with a digital camera was 2.37 and 4.21, respectively in the same group. The application of fluoride varnish in the evaluation of a spectrophotometer and a digital camera resulted in a statistical significant color change in samples (respectively p<0.001 and p=0.028). In addition, the data showed a significant correlation in obtained results from spectrophotometer and digital camera (p=0.045 and r=0.357).

CONCLUSION: Based on the results of this study in evaluation by spectrophotometry, application of fluoride varnish (Dura shield) led to an apparent color change in both ionomer glass. According to the same results, digital camera for evaluation of color is relatively reliable.