Department of Prosthetic Dental Sciences, College of Dentistry, Taibah University, Madinah Munawwarah, Saudi Arabia.
J Prosthodont. 2012 Apr;21(3):167-72. doi: 10.1111/j.1532-849X.2011.00803.x. Epub 2012 Feb 28.
Marginal adaptation is an important factor affecting the longevity of all-ceramic restorations, although the effects of different fabrication steps on marginal adaptation at various stages of fabrication are not fully understood. The purpose of this study was to assess with an in vitro model whether In-Ceram alumina (IA) or In-Ceram zirconia (IZ) copings produced by the CAD/CAM method would be clinically acceptable, and to evaluate the effect of each fabrication step (post-milling, post-trimming, and post-glass infiltration) on the marginal discrepancy of the coping.
A melamine tooth was prepared, duplicated, poured with inlay wax, and then cast with metal to fabricate a master die. An InLab 3D system was used to scan the master die and to design and mill the copings. Thirty IA and IZ copings each were developed with thicknesses of 0.6 mm and a 30-μm thick computer luting space. Epoxy resin replicas of the master die were fabricated, and the vertical and horizontal marginal discrepancies were measured using a Micro-Vu optical microscope at three stages of the fabrication (post-milling, post-trimming, post-infiltration). One-way ANOVA was used to analyze the data between the three stages of fabrication for each marginal discrepancy, and a t-test was used to compare vertical and horizontal marginal discrepancies (after glass infiltration) between IZ and IA copings
There were no significant differences (p > 0.05) in the vertical marginal discrepancies (μm) between IA (36 ± 14) and IZ (40 ± 14) copings after glass infiltration. ANOVA (comparing three stages within horizontal marginal discrepancy for IZ copings) showed that post-milling (40 ± 26) > post-trimming (23 ± 11) = post-infiltration (19 ± 13). ANOVA (comparing three stages within vertical marginal discrepancy for IZ copings) showed that post-milling (53 ± 12) = post-trimming (47 ± 13) > post-infiltration (36 ± 14). ANOVA (comparing three stages within horizontal marginal discrepancy for IA copings) showed that post-milling (52 ± 28) > post-trimming (30 ± 16) > post-infiltration (30 ± 16). ANOVA (comparing three stages within vertical marginal discrepancy for IA copings) showed that post-milling (54 ± 13) = post-trimming (56 ± 26) > post-infiltration (40 ± 14).
There was no significant difference in the marginal adaptation of both material copings. After the trimming process, the glass infiltration firing cycle improved the vertical marginal discrepancy for both IZ and IA copings. Clinical implications. IA and IZ copings fabricated by CAD/CAM technology have an acceptable marginal fit as documented in the literature, and the glass infiltration process improves the marginal fit after machining.
边缘适合性是影响全瓷修复体寿命的一个重要因素，尽管不同制作步骤在制作过程的不同阶段对边缘适合性的影响尚不完全清楚。本研究的目的是通过体外模型评估 CAD/CAM 方法制作的 In-Ceram 氧化铝（IA）或 In-Ceram 氧化锆（IZ）修复体是否具有临床可接受性，并评估每个制作步骤（后研磨、后修整和后玻璃渗透）对修复体边缘间隙的影响。
制作一个三聚氰胺牙，复制，倒入嵌体蜡，然后用金属铸造制作母模。使用 InLab 3D 系统扫描母模并设计和研磨修复体。制作 30 个 IA 和 IZ 修复体，厚度为 0.6 毫米，计算机黏结空间厚度为 30μm。制作母模的环氧树脂复制品，使用 Micro-Vu 光学显微镜在制作的三个阶段（后研磨、后修整、后渗透）测量垂直和水平边缘间隙。使用单向方差分析比较每个边缘间隙在制作的三个阶段之间的差异，使用 t 检验比较 IZ 和 IA 修复体在后玻璃渗透后的垂直和水平边缘间隙。
玻璃渗透后，IA（36 ± 14）和 IZ（40 ± 14）修复体的垂直边缘间隙（μm）无统计学差异（p > 0.05）。对于 IZ 修复体的水平边缘间隙，方差分析（比较三个阶段内的差异）显示后研磨（40 ± 26）>后修整（23 ± 11）=后渗透（19 ± 13）。对于 IZ 修复体的垂直边缘间隙，方差分析（比较三个阶段内的差异）显示后研磨（53 ± 12）=后修整（47 ± 13）>后渗透（36 ± 14）。对于 IA 修复体的水平边缘间隙，方差分析（比较三个阶段内的差异）显示后研磨（52 ± 28）>后修整（30 ± 16）>后渗透（30 ± 16）。对于 IA 修复体的垂直边缘间隙，方差分析（比较三个阶段内的差异）显示后研磨（54 ± 13）=后修整（56 ± 26）>后渗透（40 ± 14）。
两种材料修复体的边缘适应性无显著差异。修整后，玻璃渗透烧结循环改善了 IZ 和 IA 修复体的垂直边缘间隙。临床意义。CAD/CAM 技术制作的 IA 和 IZ 修复体具有可接受的边缘适合性，文献中有记载，玻璃渗透过程可以改善加工后的边缘适合性。
