- 學位論文
不同製程鈷鉻合金和瓷層厚度對最終顏色的影響
Effect of different manufacturing methods of cobalt-chromium alloy on the final color with different thicknesses of porcelain layer
摘要
鈷鉻合金之金屬燒附陶瓷冠 (porcelain fused to metal, PFM)具備優良的機械性能、美觀性和適宜的價格，因此廣泛地應用在牙科的固定義齒製作中。數位牙科技術已成為現今的主流，因此掌握傳統與數位製程鈷鉻合金陶瓷冠的最終顏色相當重要，以符合患者對美觀的要求。目前，不同種類的金屬合金已被證實是影響PFM最終顏色的因素之一，而單就鈷鉻合金的製程對PFM最終顏色的影響仍未被探討。本實驗的目的為探討不同製程和瓷層厚度對於燒瓷的最終顏色的影響。 本實驗選擇鑄造 (casting)、選擇性雷射熔融 (selective laser melting, SLM)、電腦輔助設計／電腦輔助製造 (computer aided design and manufacturing, CAD/CAM)三種製程用以製作牙科用鈷鉻合金，每組製程有15個樣本(尺寸：13×13×0.3 mm)，再以燒瓷程序覆上不透光瓷 (0.1 mm)，並隨機分配至三種不同的厚度的牙本質瓷層組別 (0.5、0.7和0.9 mm)，每組5個樣本。利用比色儀進行檢測CIE之L*、a*與b*值，並將Ivoclar IPS Inline A3比色板作為色差值ΔE *00之比較基礎。實驗數據以雙因子變異數分析進行分析 (α=0.05)。 結果發現不同製程的鈷鉻合金在經過不同厚度的燒瓷，平均色差值最小為CAD/CAM燒附0.9 mm的牙本質瓷 (ΔE*00=4.13±0.37)，最大為casting燒附0.5 mm的牙本質瓷 (ΔE*00=6.42±0.43)，均超過感知閾值 (perceptibility thresholds, PT)之ΔE *00=0.8和可接受閾值 (acceptability thresholds, AT) 之ΔE *00=1.8。且不同鈷鉻合金製程和牙本質瓷層厚度對最終顏色的影響皆有顯著的影響 (p<0.001與p<0.001)，並且具有交互作用。 本研究提供不同製程鈷鉻合金在經過不同厚度燒瓷後的色差值，可供牙技師於燒瓷過程中對顏色控制的參考，而在臨床上空間的限縮下，以CAD/CAM燒附0.9 mm的牙本質瓷能達到最小的色差值。
並列摘要
Cobalt-chromium alloy (Co-Cr alloy) is widely used in the manufacturing of porcelain-fused-to-metal (PFM) crowns in fixed prosthodontics field due to its excellent mechanical properties, aesthetics, and desirable prices. Digital dental technology has become mainstream today. Therefore, it is important to master the final color of traditional and digital Co-Cr porcelain-fused-to-metal crown to meet the aesthetic requirements of patients. Recently, different types of metal alloys have proven to be one of the factors that affect the final color of PFM. However, the influence of the process for the Co-Cr alloy on the final color of PFM has not been thoroughly investigated. The purpose of this study was to investigate the effect of different processes of Co-Cr alloy and the thickness of the porcelain layer on the final color of the porcelain. Forty-five Co-Cr alloy specimens (13×13×0.3 mm) were fabricated by employing casting, selective laser melting (SLM), and computer-aided design/computer-assisted manufacturing (CAD/CAM) technology. First, opaque porcelain (0.1 mm) was sintered onto the specimens and randomly assigned to three different thickness dentin porcelain layer groups (0.5, 0.7, and 0.9 mm), with 5 samples in each group. The Ivoclar IPS Inline A3 shade guide was used as the base for comparing the different color variation values (ΔE*00). The L*, a*, and b* of each group were measured with a colorimeter, and the ΔE*00 between samples and colorimetric plate was calculated. A two-way ANOVA analysis was performed on the data (α=0.05). It was found that casting with 0.5 mm dentin porcelain rendered the maximum color variation value ΔE*00=6.42±0.43, and CAD/CAM with 0.9 mm dentin porcelain rendered the minimum color variation value ΔE*00=4.13±0.37. The color variation value of each group exceeds ΔE *00=0.8 of the perceptibility thresholds (PT) and ΔE*00=1.8 of acceptability thresholds (AT). Different processes of Co-Cr alloy and dentin porcelain layer thickness have a significant effect on the final color (p<0.001 and p<0.001 for both) as well as their interaction (p=0.024). This study provides the color variation values of Co-Cr alloys with different processes and thicknesses of dentin porcelain, which can be used by dental technicians to refer to color control during the porcelain process. Within the clinical limitation, CAD/CAM with 0.9 mm dentin porcelain can achieve the smallest color variation value.