Hijazi Khaled Mahmoud, Abo Elezz Ahmed Fawzy, Ghonaim Amr Faisal
Suez Canal University, Ismaileya, Egypt.
BMC Oral Health. 2025 Jul 3;25(1):1082. doi: 10.1186/s12903-025-06424-1.
Dentists have started to use universal shade resin composites to simplify shade selection. This in vitro study assessed the color matching of two distinct universal shade resin composites (OMNICHROMA and ONEshade) following immersion in staining solution and their microhardness during thermocycling.
For color matching evaluation, forty maxillary sound human premolars were collected. Only A3 shaded teeth were chosen after VITA Easyshade V recorded the color coordinates of the teeth via the CIELab color system before interventions. After that, the teeth were randomly allocated into two groups according to the tested materials, with twenty teeth included in each group (n = 20). The teeth were then prepared with class V cavity preparations, the group (M1) teeth were restored with Omnichroma, and the group (M2) teeth were restored with Oneshade. All teeth were evaluated after 24 h of restoration (T1), after 3 months of immersion in tea solution (T2) and after 6 months of immersion in tea solution (T3). To evaluate color matching, both instrumental and visual color changes were recorded. For microhardness evaluation, forty cylindrical discs were made (20 discs for each composite group M1 and M2). Vickers microhardness measurements were performed via a microhardness testing machine. The samples were measured at baseline (C1), after 2500 thermocycles (C2) and after 5000 thermocycles (C3).
In accordance with the color matching results, both tested composite materials showed significant color mismatching after immersion in tea solution. In accordance with the surface microhardness evaluation, both tested resin composite materials showed a significant decrease in the Vickers microhardness after thermocycling.
Following immersion in the staining solution, both evaluated resin composite materials displayed unsatisfactory color matching values in class V restorations. Accelerated aging by thermocycling had an obvious negative effect on the microhardness of the universal shade resin materials.
牙医已开始使用通用色度树脂复合材料以简化色度选择。本体外研究评估了两种不同的通用色度树脂复合材料（OMNICHROMA和ONEshade）在浸入染色溶液后的颜色匹配情况及其在热循环过程中的显微硬度。
为评估颜色匹配，收集了40颗上颌健康人前磨牙。在VITA Easyshade V通过CIELab颜色系统在干预前记录牙齿的颜色坐标后，仅选择A3色度的牙齿。之后，根据测试材料将牙齿随机分为两组，每组20颗牙齿（n = 20）。然后对牙齿进行V类洞制备，M1组牙齿用Omnichroma修复，M2组牙齿用Oneshade修复。所有牙齿在修复24小时后（T1）、浸泡在茶溶液3个月后（T2）和浸泡在茶溶液6个月后（T3）进行评估。为评估颜色匹配，记录了仪器测量和视觉观察的颜色变化。为评估显微硬度，制作了40个圆柱形圆盘（M1和M2复合材料组各20个圆盘）。通过显微硬度测试机进行维氏显微硬度测量。在基线（C1）、2500次热循环后（C2）和5000次热循环后（C3）对样品进行测量。
根据颜色匹配结果，两种测试的复合材料在浸入茶溶液后均显示出明显的颜色不匹配。根据表面显微硬度评估，两种测试的树脂复合材料在热循环后维氏显微硬度均显著降低。
浸入染色溶液后，两种评估的树脂复合材料在V类修复体中的颜色匹配值均不理想。热循环加速老化对通用色度树脂材料的显微硬度有明显的负面影响。
