近年來材料科學演進、數位加工製程、審美牙科的興起，氧化鋯陶瓷逐漸成為復形物主流。第一代氧化鋯含3mol %氧化釔，雖然在機械強度、化學穩定度上，有優異的表現，但透明度低：因應美觀需求，發展出第二代高透光氧化鋯(high-translucency zirconia)；2015年更提高氧化釔至5mol％，開發第三代極高透光氧化鋯(ultra-translucency zirconia)，用於製作單層或超薄複合物，具有美學效果，也可減少燒瓷、陶瓷鑲面剝落、牙齒修磨過厚等問題。
氧化鋯是一種耐酸陶瓷，所以與樹脂的鍵結是一大挑戰。目前氧化鋯復形物多以甲基丙烯酰氧基二氫磷酸酯(10-MDP) 表面處理，以樹脂黏著劑固定於支台齒；然而，高透光氧化鋯的不同化學組成可能影響對10-MDP 的親和性，而透明度可能提升樹脂聚合。因此，本研究目的擬探討不同種類之透明氧化鋯其化學組成與透明度，是否影響與10-MDP的親和性以及對於樹脂黏著劑聚合的影響。
研究選擇六種不同透明度氧化鋯製作樣本，分別為Cercon廠牌氧化鋯之第一代傳統氧化鋯Cercon base，第二代高透氧化鋯 Cercon HT，第三代極透 Cercon XT；與Vita廠牌氧化鋯之第二代高透氧化鋯 Vita HT，第三代極透 Vita ST 和Vita XT。首先分析材料本身的密度及親水性，再來以電子顯微鏡分析晶粒大小與元素組成。第三部分，分析不同透度之氧化鋯對聚合用藍光穿透率、樹脂聚合程度的影響，利用分光光譜儀分析穿透率、吸收度、反射率和透明度。第四部份，檢測含有10 -MDP為基底的黏著劑對不同透光度氧化鋯的化學鍵結，首先以X射線光電子能譜儀 (XPS)來檢查黏著劑塗層之附著比例。最後，進行剪切粘結強度測試(Shear Bond Strength test)評估黏著強度。本研究希望檢視不同透光度之氧化鋯，臨床上可能的黏著表現。
於材料的基本性質檢查發現第一代的密度較第三代的密度高；而親水性則是第三代Vita XT較第一代高。第二部分實驗中，電子顯微鏡檢查結果發現第三代極高透光氧化鋯的晶粒大小比第一代氧化鋯大；經由元素組成分析，第三代氧化鋯所含的氧化釔含量較高，而第一代氧化鋯所含的氧化鋁含量較高，第一、二代氧化鋯Cercon base (1st), Cercon HT(2nd) and Vita HT(2nd)所含的c相比例較低，。第三部分，藉由分光光譜儀分析，以厚度為0.5、1.0毫米氧化鋯瓷片測試，藍光（486nm）之穿透率依序為Cercon XT (3rd)、Vita XT (3rd)、Vita ST(3rd)、Cercon HT (1st)、Vita HT (2nd), Cercon base (1st)，有統計差異，也因此影響樹脂聚合程度。第四部分，在化學分析方面，當MDP 底劑塗布並沖洗後，Vita HT 與Vita ST有最多的殘留量，而Cercon base 最低。於第五部分剪切黏結強度，發現不同透度的氧化鋯在測試雖無統計差異，但Vita HT 與Vita ST的黏結強度略高，而Cercon base 最低。
本研究探討不同透度氧化鋯的性質，發現不同代之氧化鋯的確有不同化學組成，也因此影響其微結構、物理性質、相組成、透明度、與對10-MDP 的親和性，且高透氧化鋯之透明度與樹脂聚合度有關。不同種類氧化鋯對MDP 的親和性似乎也不同，且可能與最終的黏著表現相關。

With the advanced material sciences, the introduction of computer-aided manufacturing, and the promotion of esthetic dentistry, zirconia ceramics have become the most popular restorative materials. Conventional zirconia (1st) with 3 mol% yttria presents high strength and chemical stability but is not translucent. Due to aesthetics requirements, high translucency (2nd) zirconia was introduced in 2012 as the second generation. In 2015, the ultra-translucency (3rd) zirconia was developed as the third generation by increasing yttria to 5mol％. It can be used in monolithic restorations to provide better esthetics and reduce tooth preparation in prosthodontic rehabilitation.
Zirconia restorations rely on the surface treatment with 10-MDP and the resin cement to be fixed onto the abutment. However, the different components of high-translucency zirconia may interfere with the adhesion of zirconia with 10-MDP. On the other hand, their translucency may promote resin polymerization. Hence, the aim of our study was to investigate the effects of the chemical compositions and transmittance of high-translucency zirconia restorations in regard to the affinity to 10-MDP and resin cement polymerization.
Six zirconia ceramics of different generations and manufacturers were included. Three ceramics were from Cercon: conventional zirconia Cercon Base (1st generation), high translucency Cercon HT (2nd), ultra-translucency Cercon XT (3rd), and three from Vita: Vita HT(2nd), Vita ST (3rd), and XT (3rd). Zirconia discs were prepared and sintered. Their density and surface wettability were first measured. In the second part, the morphological and chemical properties were measured by SEM, EDX and XPS. In the third part, their optical properties (transmittance, reflectance, and absorption) and the translucency (transparency parameter and contrast ratio) were measured by UV-NIR spectrophotometer. The micro-hardness tester detects resin polymerization after blue light irradiation. The fourth part was to examine the bonding and residuals of MDP on zirconia by XPS. Finally, shear bond strengths (SBS) after treating zirconia with MDP were determined. The purpose of the study was to investigate the cementation properties of high-translucency zirconia restorations.
In the results, the first generation presented the highest sintering density compared to the third generation of zirconia. On the contrary, the third generation Vita XT showed a significantly higher wettability. Both 3rd generation XT zirconia showed greater mean grain sizes by the Y2O3 content. The first generation has higher Al2O3. The 1st and 2nd generation zirconia exhibited less c phase than the 3rd generation ones. The mean light transmittance values (at 468nm) ranked in order were Cercon XT (3rd), Vita XT (3rd), Vita ST (3rd), Cercon-HT (1st), Vita HT (2nd), Cercon base(1st), which is also correlated to the results of microhardness of resin immediately or after 24 hours after curing. In the chemical analysis of MDP affinity, Vita HT and Vita ST showed the highest MDP residual after washing, while Cercon base was the lowest. Although the shear bond strength test did not show differences among groups, Vita HT and Vita ST showed higher SBS and Cercon base the lowest.
The present study investigated the properties of different translucency zirconia and disclose that the chemical compositions, microstructure, physical properties, phase compositions, translucency, and affinity to MDP all varied. These variations could be related to their bond performances.

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