Farhan Daniel, Sukumar Smitha, von Stein-Lausnitz Axel, Aarabi Ghazal, Alawneh Ahmad, Reissmann Daniel R
Department of Prosthetic Dentistry, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; dental Praxis, Kaltenkirchen, Germany.
J Esthet Restor Dent. 2014 Jul-Aug;26(4):232-9. doi: 10.1111/jerd.12099. Epub 2014 Jun 30.
A predictable esthetic outcome is imperative when placing ceramic veneers. Discolored teeth pose a major challenge as sufficient material thickness is required to achieve a good esthetic result. There is limited evidence in the literature that compares the masking ability of multi-laminate veneers.
The aim of this in-vitro study was to compare the masking ability of bi-laminate (BL) and tri-laminate (TL) all-ceramic veneers cemented on tooth-colored ceramic discs.
A total of 40 veneers (shade A1, 10-mm diameter, 0.8-mm thick) were manufactured-20 BL veneers (0.4-mm pressable ceramic coping veneered with 0.4-mm thick enamel layer) and 20 TL veneers (0.4-mm coping veneered with 0.2-mm thick opaque interlayer and 0.2-mm thick enamel layer). A bonding apparatus was utilized to adhesively cement all veneers on the ceramic discs (shade A1), simulating teeth of light and dark color. The resulting groups (N = 10 each) were the reference groups (shade A1 ceramic base) BL-1 and TL-1 veneers, and the test groups (shade A4 ceramic base) BL-4 and TL-4 veneers. The color of the cemented veneers was measured using a spectrophotometer. The data were converted to CIE Lab* coordinates, and ΔE* were calculated to allow for statistical analysis.
The color differences between the samples with the A1 and A4 ceramic bases were significantly lower when covered with TL veneers (mean ΔE*: 3.2 units) than with BL veneers (mean ΔE*: 4.0 units: p < 0.001), indicating a better masking ability of the TL veneers.
The 0.8-mm thick TL veneer was able to mask darker tooth-colored ceramic disc within clinically acceptable limits.
Increased understanding of the masking ability of ceramics and of color science is necessary in these esthetically aware times. Providing tri-laminate veneers for darker colored teeth seems to result in more predictable esthetical results than when using bi-laminate veneers. Patients with discolored/darker teeth may benefit from a more predictable esthetic result when teeth restored with tri-laminate rather than bi-laminate veneers.
放置陶瓷贴面时，可预测的美学效果至关重要。牙齿变色是一个重大挑战，因为需要足够的材料厚度才能获得良好的美学效果。文献中比较多层陶瓷贴面遮盖能力的证据有限。
本体外研究的目的是比较粘结在牙齿颜色的陶瓷盘上的双层（BL）和三层（TL）全瓷贴面的遮盖能力。
共制作40个贴面（A1色，直径10mm，厚0.8mm）——20个双层贴面（0.4mm可压制陶瓷基底覆盖0.4mm厚的釉质层）和20个三层贴面（0.4mm基底覆盖0.2mm厚的不透明中间层和0.2mm厚的釉质层）。使用粘结装置将所有贴面粘结在陶瓷盘（A1色）上，模拟浅色和深色牙齿。得到的组（每组N = 10）为参考组（A1色陶瓷基底）BL-1和TL-1贴面，以及测试组（A4色陶瓷基底）BL-4和TL-4贴面。使用分光光度计测量粘结后贴面的颜色。将数据转换为CIE Lab坐标，并计算ΔE以进行统计分析。
当用三层贴面覆盖时，A1和A4陶瓷基底样本之间的颜色差异（平均ΔE*：3.2单位）明显低于双层贴面（平均ΔE*：4.0单位：p < 0.001），表明三层贴面具有更好的遮盖能力。
0.8mm厚的三层贴面能够在临床可接受的范围内遮盖深色牙齿颜色的陶瓷盘。
在这个注重美学的时代，有必要加深对陶瓷遮盖能力和颜色科学的理解。为深色牙齿提供三层贴面似乎比使用双层贴面能带来更可预测的美学效果。牙齿变色/深色的患者在用三层贴面而非双层贴面修复牙齿时，可能会从更可预测的美学效果中受益。
