Department of Restorative Dental Science, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
Department of Prosthodontics, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia.
J Appl Biomater Funct Mater. 2021 Jan-Dec;19:22808000211058866. doi: 10.1177/22808000211058866.
To investigate the effects of a coffee beverage and two whitening systems on the surface roughness and gloss of glazed Lithium Disilicate Glass-Ceramics (LDGC) for computer-aided design/computer-aided manufacturing (CAD/CAM) systems.
Sixty-eight LDGC disks (12 × 10 × 2 mm) were prepared from blocks of CAD/CAM systems (IPS e.max CAD ceramic). Baseline measurements for surface roughness (Ra) and gloss (GU) were taken using a 3-D optical profilometer and a glossmeter, respectively; then specimens were randomized into four groups ( = 17). All specimens were immersed in a coffee solution (24 h × 12 days) then subjected to two whitening systems. G1-negative control (kept moist × 7 days); G2-positive control (brushed with distilled water, 200 g/load, 2 min twice daily × 7 days); G3-whitening toothpaste (Colgate optic white; relative dentin abrasivity (RDA) = 100, 200 g/load, 2 min twice daily × 7 days); and G4-simulated at-home bleaching protocol (Opalescence,15% carbamide peroxide (CP), 6 h/day × 7 days). The study outcomes were measured at baseline and after the treatments. Data were analyzed using paired -test and one-way ANOVA (α = 0.05).
The mean surface roughness significantly increased ( ⩽ 0.002) for all groups after the designated treatment protocols. Among groups, the mean surface roughness of G2 and G3 were significantly higher ( ⩽ 0.001) (Ra: 0.51 and 0.57 μm, respectively) compared to the control group (Ra: 0.23 μm), and were not significantly different from G4 (Ra: 0.46 μm). Surface gloss decreased with no significant change within or among groups after treatment.
All glazed LDGC had a significant increase in surface roughness after being subjected to simulated 1 year of coffee drinking and whitening systems (15% CP and whitening toothpaste), and the greatest change was associated with brushing (simulating 8 months). However, coffee beverages and whitening systems had no significant effect on the surface gloss.
研究咖啡饮料和两种美白系统对计算机辅助设计/计算机辅助制造（CAD/CAM）系统用釉面锂硅玻璃陶瓷（LDGC）表面粗糙度和光泽度的影响。
从 CAD/CAM 系统块（IPS e.max CAD 陶瓷）制备 68 个 LDGC 圆盘（12×10×2mm）。使用三维光学轮廓仪和光泽计分别对表面粗糙度（Ra）和光泽度（GU）进行基线测量；然后将标本随机分为四组（每组 17 个）。所有标本均浸入咖啡溶液中（24 h×12 天），然后用两种美白系统处理。G1-阴性对照组（保持湿润×7 天）；G2-阳性对照组（用蒸馏水刷，200g/负载，每天两次，每次 2 分钟×7 天）；G3-美白牙膏（高露洁光学白；相对牙本质磨损率（RDA）=100，200g/负载，每天两次，每次 2 分钟×7 天）；G4-模拟家庭漂白方案（Opalescence，15%过氧化脲（CP），每天 6 小时×7 天）。在基线和治疗后测量研究结果。使用配对 t 检验和单向方差分析（α=0.05）进行数据分析。
所有指定处理方案后，所有组的表面粗糙度均显著增加（≤0.002）。在各组中，与对照组（Ra：0.23μm）相比，G2 和 G3 的平均表面粗糙度（Ra：0.51 和 0.57μm）显著更高（≤0.001），与 G4 无显著差异（Ra：0.46μm）。处理后，各组内和组间的表面光泽度均无明显变化。
所有釉面 LDGC 在经过模拟一年的咖啡饮用和美白系统（15% CP 和美白牙膏）后，表面粗糙度均显著增加，最大变化与刷牙有关（模拟 8 个月）。然而，咖啡饮料和美白系统对表面光泽度没有显著影响。
