Objective   To compare the accuracy of the digital model constructed by 5 different scanning methods in CEREC 3D/inLab MC XL system in order to explore the best scanning method

and to provide reference for clinical use.    Methods   A standard implant abutment was used as the scanning object in this experiment. Then 5 different scanning methods

including Top view

inEos Rotational

inEos TopRot

inLab MC XL Scanner

and CEREC Bluecam

was used respectively to construct the digital models of the implant abutment. The upper surface diameter

gingival margin diameter and distance from the upper surface edge to the gingival margin of the abutment and the digital models were measured respectively. The results were statistically analyzed by using SAS9.2.    Results   By eye view

these constructed digital models had significantly difference. The constructed digital model by inEos Rotational had the clearest feature

such as every single line and every angle. The inEos Top view model and the CEREC Bluecam models displayed the details of axial planes not clear enough. Some undercuts were ignored

the edge was fuzzy

and some distortion existed. SNK-q pairwise test showed that there was no significant statistical difference in the measured data from the digital models constructed by inEos Rotational and inLab MC XL Scanner with object itself (P0.05). However

the experiment results of the other 3 scanning methods had significant difference with the results of the object (P0.05).    Conclusion   Of the 5 scanning methods of CEREC 3D/inlab MC XL system

inEos Rotational and inLab MC XL Scanner can achieve more accurate digital model. inEos Top view

combined use of inEos Top view and Rotational as well as the CEREC Bluecam are not comparatively good enough.