Abstract

ALVES, Julia Késia G. et al. Composite color evaluation using a spectrophotometer in different modes of operation and storage conditions. RFO UPF [online]. 2014, vol.19, n.1, pp. 101-106. ISSN 1413-4012.

Objective: To assess whether the VITA Easyshade™ Compact spectrophotometer performs similar color measurements of Filtek™ Z350 composite resin, by comparing two modes of operation. To verify whether the hydration of the composite influences these readings, and whether there is color difference between the composite resin used and the Vita Classical shade guide. Materials and method: Ten specimens of A2-shade composite resin were made using a 6 mm-diameter and 2 mm-thick teflon matrix, photoactivated for 40 seconds. The CIELAB system and A2 Vita Classical shade guide color coordinates of specimens were measured using the spectrophotometer in the "single tooth" mode to calculate color difference (ΔE*) between specimens and the Vita Classical shade guide. ΔE* values in "restoration" mode were also obtained. In this function, the spectrophotometer compares the specimen color to a preloaded proper scale. These measurements were repeated after 24h of hydration in deionized water. The paired t Student test (α=0.01) was applied for group comparisons. Results: Significant differences were found between modes of operation (p<0.01) in both conditions (baseline and 24h), and between hydration periods (baseline and 24h) also for both modes of operation, with lower ΔE* values after hydration. Conclusion: The VITA Easyshade™ Compact spectrophotometer performed different color measurements of the composite resin tested in both modes of operation, also influenced by hydration. The Filtek™ Z350 composite resin A2-shade did not match Vita Classical A2-shade guide tab.

Keywords : Color.; Composite resins.; Spectrophotometers..