四種牙科用 CAM 系統加工尺寸精密度之研究

本研究目的探討不同牙科電腦輔助製造(CAM)系統製作的氧化鋯與樹脂牙冠的邊緣間隙差異，並比較四種牙科CAM系統加工的精密度。研究中使用牙科專用不鏽鋼金模來作為支台齒，CAD系統製作其數位支台模型和數位牙冠，再分別利用四間廠牌（Taicrown, Arix, Wieland和Sirona X5）CAM系統加工製作陶瓷牙冠和樹脂牙冠，戴入原金屬模型測量牙冠邊緣與支台齒間的間隙，並利用 One-way ANOVA 統計分析。結果顯示Taicrown與Arix所製作出來的氧化鋯牙冠其邊緣間隙比Sirona X5佳，且在統計上有明顯的差異性(p<0.05)。研究結果也顯示，在不同CAM系統製作的樹脂牙冠間的邊緣差異無明顯不同(p>0.05)，均在臨床可接受的範圍內。本研究的結果證明Taicrown、Arix和Wieland的CAM系統的加工精密度較好，無論是陶瓷或是樹脂牙冠的邊緣精密度均在臨床可接受的範圍內。

The purpose of this study was to investigate margin discrepancies of zirconia or resin crowns created with different CAM systems to compare the processing accuracy of four dental CAM systems. The stainless steel standard abutment teeth was used to scan by a dental extra-oral scanner and design a virtual dental crown from the dental CAD system. The zirconia and resin crowns were fabricated from four CAM machines. The crown were placed on the original metal abutment teeth. The marginal gap was measured using a profile projector. The results showed that the zirconia crowns obtained with the Wieland and Sirona X5 CAM systems were slightly smaller. One-way ANOVA revealed that the processing accuracy of Taicrown and Arix were significantly better than that of Sirona X5 (p<0.05). The CAM system factor was significant. There was no statistically significant difference in margin discrepancies of resin crowns created with different CAM systems (p>0.05). Results of the present study suggest the marginal adaptation accuracy of zirconia crowns made with the Taicrown and Arix CAM systems were within the acceptable clinical limit. These results suggested that Taicrown and Arix CAM systems have higher processing accuracy in comparison with Sirona X5.