Inlab MC XL系统3种全瓷冠边缘和内部适合性的实验研究

Marginal and Internal Fit of Three All-ceramic Crowns in Inlab MC XL System

目的研究Inlab MC XL系统3种瓷材料全冠的边缘和内部适合性,为临床应用提供参考。方法制备一右下第一磨牙全冠预备体模型,复制48个代型。采用随机抽样法,24个用于采集光学印模,分别制作8个Cerec Blocs、Incoris AL、In-ceramYZ全冠,剩余24个代型用于冠的粘结。采用修正USPHS标准和SEM法评价冠的适合性。结果修正USPHS法显示87.5%的边缘测试点临床可接受,3种瓷材料冠的边缘适合性比较无统计学意义(P>0.05);SEM法显示Incoris AL组的边缘适合性与Cerec Blocs组、In-ceram YZ组比较有统计学意义(P<0.05);3个实验组在近中、远中、颊面、舌面、内部整体等观察项的适合性比较有较显著统计学意义(P<0.01)。结论 Cerec Blocs、In-ceram YZ冠的边缘适合性优于Incoris AL,而Cerec Blocs的内部适合性最好;3种瓷材料冠的边缘适合性均在临床可接受范围内。

Objective To investigate marginal and internal fit of three types of all the porcelain crowns in Inlab MC XL system and provide experimental evidences for its clinical application.Methods A lower right first molar in the standard model was prepared with 48 models also duplicated.Among them,24 models were randomly selected to bind crowns and the other 24 models were used to bind Cerec Blocs,Incoris AL and In-ceram YZ crowns at the same numbers respectively.The fit of all-ceramic crowns were evaluated with modified United States Public Health Service（USPHS） criteria and scanning electron microscop image （SEM）.Results All the marginal fit values were less than 120μm and there was statistical significance between Incoris AL and Cerec Blocs groups,Incoris AL and In-ceram YZ groups（P 〈 0.01）.The occlucal surface′s fit value（〉200 μm）was the poorest in all three groups,while Cerec Blocs showed better internal fit than Incoris AL and In-ceram YZ in terms of mesial surface,lingual surface,buccal surface,and internal overall （P 〈 0.05）.However,there was no statistical significance（P 〉 0.05）between Incoris AL and In-ceramYZ groups in terms of that of above observation projects.Conclusion The crowns′ marginal fit of Cerec Blocs and In-ceram YZ was better than Incoris AL with the best internal fit of Cerec Blocs.Three types of all-ceramic crowns appear to have clinically acceptable marginal fit.