不同CAD/CAM系統應用於全瓷修復體之探討

Analysis of all ceramic restorations in different CAD/CAM restorations

張志豪(Chih-Hao Chang)

指導教授 ： 洪純正

高雄醫學大學/口腔醫學院/牙醫學研究所/碩士(2009年)

摘要

研究目的︰
修復體的邊緣與內部密合度是最常被用來評估牙科修復體的指標。多數的CAD/CAM系統採用間接法取得口腔內資料，本實驗比較修復體咬合面高度變化、邊緣及內部密合度，評估直接與間接掃描模式對於CAD/CAM修復體的精確性的影響。

材料與方法︰
以金屬支台齒﹙048.160 ,ITI System; Straumann）取代牙齒25，分別利用Cerec 3D、Cerec inLab、Procera三個系統進行修復體設計。Cerec 3D以口內攝影機搭配感光粉末紀錄支台齒資料，Cerec inLab與Procera分別使用雷射掃描及機械式接觸掃描紀錄工作模型。Cerec 3D及Cerec inLab兩組使用材料是VITA MARK II，Procera則是氧化鋯。每組樣本數為5個，直接製成單顆牙冠不再進行後續處理以避免變形。試戴確定無干擾後將樣本定位回標準模型，利用三維立體測量儀量測咬合面座標，並標記切割線位置。樣本以磷酸鋅黏著劑固定，給予50穩定牛頓壓力直到固化完全，再以樹脂包埋進行多重切割，直接觀測內部及邊緣密合度（100X）。分別對咬合面高度變化、邊緣密合度、內部密合度設定統計模組，並將各因子之間交互作用併入模組﹙α=0.05﹚。樣本數若有未達常態分布或未能滿足中央極限定理的項目，則以無母數統計加以分析﹙α=0.05﹚。

結果︰
邊緣密合度平均為114.3±26.83μm，在不同面之間無差異性，Cerec 3D組顯著較大；內部密合度平均為123.2±35.93μm，其中Cerec 3D與Cerec inLab無差異性而Procera顯著較小，在不同面、高度與CAD/CAM系統間其內部密合度均有差異性。咬合面高度變化平均為112.0±110.25μm，在Procera與Cerec inLab無差異性而Cerec 3D顯著較大，在不同CAD/CAM系統、位置其咬合面高度變化均有差異性。

結論︰
直接掃描模式提供了臨床使用上的便利性，然而在本次實驗設定的條件下，其修復體精確性仍不及間接法。

關鍵字

CAD/CAM ； 數位化 ； 邊緣密合度 ； 內部密合度 ； 咬合面精確性

並列摘要

Objective:
Internal and marginal fitness are the most commonly used parameters in measuring dental restorations. The majority of current CAD/CAM systems use indirect method to obtain intra-oral information. Change of occlusal height, marginal and internal fitness were used in this study to evaluate the influences of direct and indirect digital techniques for CAD/CAM restorations..

Materials & methods:
Implant analog (048.160, ITI System; Straumann) was used to replace the teeth 25. Three CAD/CAM systems, Cerec 3D, Cerec inLab and Procera systems were used in this study. For Cerec 3D system, intra-oral camera combined with anti-reflecting powder was used to collect abutment information; Cerec inLab and Procera use laser scan and mechanical contact digitalization respectively. VITA MARK II blocks were used for Cerec inLab and Cerec 3D systems while zirconia was used in procera. Each sample was made directly into the form of a single crown,five samples for each group. No post-treatments were made in order to avoid further deformities. All samples were fit back to the standard model to insure no interference present. 3D coordinate measuring machine was used to measure changes of occlusal surface and mark the location of cutting lines. Samples were set with zinc phosphate cement. Continuously static pressure of 50 Newton was applied until cement completely set. Multiple cutting methods were used to observe the internal and marginal fitness. Interactions between multiple factors, including marginal and internal fitness, different CAD/CAM systems, surfaces were incorporated into the statistical module settings (α = 0.05). If the sample size of statistic models cannot reach normal distribution and Central Limit Theorem, nonparametric statistics（Kruskal-Wallis/ Wilcoxon Rank Sum / Signed Rank Test） were used to analyze the data（α＝0.05）.

Results:
Mean marginal fitness was 114.3 ± 26.83μm, no difference between surfaces. Cerec 3D group was significantly larger while Cerec inLab and Procera did not difference from each other. Mean internal fitness was 123.2 ± 35.93μm, no difference between Cerec 3D and Cerec inLab groups. Internal fitness was significantly different between surfaces, height and CAD/CAM systems. Change in occlusal height had an average of 112.0 ± 110.25μm, Procera and Cerec inLab did not differ from each other and Cerec 3D group was significantly larger. Change in occlusal height was significantly different between occlusal measuring points and CAD/CAM systems.

Conclusion:
Direct digitalization technique simplified clinical procedures while, less accuracy and precision for direct method comparing with indirect digitalization method was noticed under our experimental limitation

並列關鍵字

CAD/CAM systems ； digitalization ； marginal fitness ； internal fitness ； occusal accuracy

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