2010 Volume 53 Issue 2 Pages 133-139
Aesthetic tooth-coating systems have been developed to provide natural tooth color by placing a thin temporary resin layer, which is easily applied, to discolored enamel or restorations without any tooth preparation. The purpose of this study was to determine the color stability of two different tooth-coating systems using different finishing procedures according to ISO7491. Two tooth-coating systems, BeautiCoat (Shofu) and White Coat (Kuraray Medical) were evaluated, and Clearfil AP-X resin composite (Kuraray Medical) was used as the control. The White bases of BeautiCoat polymer or the Base Coat polymer of White Coat were applied to a 10mm disk of polymerized Clearfil AP-X for each disk (n=3). 1) After placing the White base on the disk and light curing it, the surface was covered with Gross Maker oxygen-inhibitor, light cured and rinsed with chip syringe water, and after 3 days the surface was polished with Gross Refine on a buff disk (standard finishing; BC). 2) After placing the White base on the disk and light curing it, the unpolymerized surface was removed with sterile gauze, and immediately polished with Gross Refine on a buff disk (GR). 3) After the White base was light-cured, the surface was covered with Gross Maker and light-cured (GM). 4) For the finishing method of the White Coat system following light-curing of its Base Coat, the unpolymerized surface layer was removed with sterile gauze, and Top Coat was applied to the unfilled surface and light-cured (WC). 5) Clearfil AP-X disks were evaluated as controls. Each specimen was evaluated according to ISO7491 for postulation of clinical long-term composite resin evaluation. Half of each specimen was covered with aluminum foil to block all light exposure and then placed under Xenon light exposure (Suntest CPS+ Type X: 45). The specimen was immersed in water at 37℃ and exposed to a 150,000 Lux Xenon light for 24hrs. The CIE L*a*b* of each specimen was measured by a Spectro Color Meter (SE-2000) with three different background values of gray, white or black. Color differences ΔE*ab and translucency parameters of each disk were calculated as well as for color stability evaluation. The results are as follows: 1. The color difference ΔE*ab between the exposed side and the protected side on a gray background was 4.29 for GM, followed by 3.40 for WC, 3.20 for GR and 2.46 for BC. 2. The color change increased toward yellow for all groups. 3. Significant differences of translucency parameter value were observed in the immediate finishing group.
