| Abstract: | 研究目的是評估五種市售氧化鋯陶瓷材料透過快速燒結方式的光學性質。實驗使用五種氧化鋯陶瓷（Copran Zr-i，Ultra-T，Ultra-T A2，Cercon ht A2和xt A2），試片尺寸為直徑12.0 mm，厚度0.5、0.8和1.2 mm。氧化鋯燒結程式依廠商提供的快速燒結（Quickly Heating，QH）和傳統燒結程式（Conventional Heating，CH）使用氧化鋯專用快速燒結爐分別燒結強化。使用兩台（VITA Easyshade V和DeguDent Shadepilot）牙科比色光譜儀測量各試片的L*（亮度）、a*、b*（顏色）值，以公式計算半透明度（TP）和顏色差異（ΔE）。用表面粗度儀測量試片表面粗糙度（Ra），以SEM觀察經不同燒結後氧化鋯試片的表面微結構，用Image J軟體測量結晶粒徑。實驗結果顯示各氧化鋯同品牌同厚度試片的光學性質，除了VITA Zr-i 0.8厚度試片的L*值因快速燒結與傳統燒結有明顯差異（p<0.05）以外，其他在不同燒結後試片的L*和TP值間差異不大，經無母數統計分析二者間沒有顯著差異（p>0.05）。五種氧化鋯同品牌不同厚度試片經不同加熱方式使用兩台牙科比色光譜儀所得的TP值都有隨著厚度的增加而降低。以DeguDent測量計算出的ΔE值均比VITA的小，色差都小於5。在不同燒結程式下同品牌結晶粒徑在QH下粒徑均較小，經無母數統計後與CH沒有顯著差異（p>0.05），但在品牌間不管燒結方式如何xt與UT和UT A2的粒徑尺寸間有統計差異（p<0.05）。Zr-i和UT A2以及ht的表面粗糙度在QH下較小，經統計後與CH的值有統計差異（p<0.05），其他品牌則沒有統計差異（p>0.05）。本研究結果證明，使用快速燒結對氧化鋯的光學性質和結晶粒徑是沒有影響，具有在牙科的應用性。但不同牙科比色光譜儀測得的光學性質數值有所不同，在牙科臨床使用上需要注意。
The purpose of the study was to evaluate the optical properties of five commercially available zirconia ceramics with quickly sintering modes. Zirconia ceramics (Copran Zr-i, Ultra-T and Ultra-T A2, Cercon ht A2 and xt A2) were used, dimensions of the specimen were 12.0 mm in diameter and 0.5, 0.8 and 1.2 mm in thickness. The zirconia specimens were heated with quickly heating (QH) or conventional heating (CH) using a sintering furnace for zirconia according to the manufacturer''s suggestions. The L* (brightness), a*, b* (color) values of each specimen were measured using two dental colorimetric spectrometers (VITA Easyshade V and DeguDent Shadepilot), and then the translucency parameter (TP) and color difference (ΔE) were calculated by the formulas. The surface roughness (Ra) of the specimen was determined using a surface analyzer, and the surface microstructure of each zirconia specimen after different sintering was observed by SEM, and the crystal grain size of the sintering zirconia was measured by Image J software. The experimental results shown that the optical properties (L* and TP) of the zirconia specimens with the same brand and thickness were not significantly different (p>0.05) after different sintering, except the L* value of Zr-i specimen with QH and CH using VITA. On the TP values obtained by two dental colorimetric spectrometers, TP values of all zirconia specimens were reduced with the increase in specimen thickness. The ΔE values of all zirconia specimens with different thickness by DeguDent measurement are smaller than those by VITA, and the color difference of the specimens between QH and CH method is less than 5. With different sintering programs, the particle size of each zirconia ceramics with QH was smaller than that with CH, and there was no significant difference between CH and QH (p>0.05). However, there was a statistical difference in the particle sizes of the specimen among xt, UT and UT A2 (p<0.05), regardless of the sintering method. The surface roughness of Zr-i, UT A2 and ht with QH was smaller. After statistical analysis, there was a statistical difference between the surface roughness of the specimens with QH and CH (p<0.05) in Zr-i, UT A2 and ht. These results suggested that the use of quick sintering on the optical properties and crystal grain size of zirconia, and has applicability in dentistry. However, the optical properties measured by different dental colorimetric spectrometers are different, and attention should be paid to the clinical use of dental. |
