Changes of optical properties of dental nano-filled resin composites after curing and thermocycling

✍ Scribed by Lee, Yong-Keun ;Lim, Bum-Soon ;Rhee, Sang-Hoon ;Yang, Hyeong-Cheol ;Powers, John M

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 82 KB
• Volume: 71B
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.b.30057

✦ Synopsis

Abstract

The objective was to evaluate the color changes after curing, polishing, and thermocycling of a nano‐filled resin composite. A nano‐filled composite was grouped into two shades of enamel (EN) and translucent (TL). One hybrid composite was used as a control (CL). Color of specimens of 10 mm in diameter and 2 mm in thickness was measured on a reflection spectrophotometer with SCE geometry under the D65 illumination over white and black backgrounds. Color before curing and after curing, polishing and thermocycling was measured. Color change (Δ__E__), translucency parameter (TP), and contrast ratio (CR) were compared. Average Δ__E__ after curing was 4.6 in the EN group and 10.4 in the TL group compare to 2.9 in CL. Polishing caused average Δ__E__ of 3.3–3.6, which was not different by the shade group (p > 0.05). After 2000 cycles of thermocycling, average Δ__E__ was 1.4–1.8, which was not different by the shade group (p > 0.05). TP values increased after curing in the EN group, but decreased in the TL group (p < 0.05). TP values after thermocycling decreased in the EN group but did not change in TL (p = 0.05). TP values of TL shades were higher than those of EN regardless of specimen conditions (p < 0.05). Changes in CR values showed similar trends to those of TP values in translucency. Changes of color and translucency after curing, polishing, and thermocycling varied by the shade group. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 16–21, 2004