Comparison of Three-Dimensional Accuracy between Digital Models Obtained from Impression Scan and Model Scan / 대한치과재료학회지

ABSTRACT

The purpose of the study is to compare and analyze the accuracy of digital images obtained from impression and stone model with model scanner and to find out clinical effectiveness. A mandibular left first molar composite resin tooth was made for abutment. Digital models were obtained with a same model scanner(Ceramill Map 400, Amann Girrbach, Austria); (1) Fabricated resin model was scanned(Group C). (2) 10 impressions were taken with putty and polyvinyl siloxane, then were scanned (Group I). (3) Type IV stone was poured in each impressions made in step(2) and 10 stone models were scanned(Group S). 3 dimensional super-impositional program (Geomagic control X, 3D Systems, USA) was used to analyze the STL files. Stone model scan(Group S) showed lower deviation than impression scan(Group I) compared to the control group(P < 0.001). Both Group I and Group S showed signs of expansion in the occlusion surface and margin surface while showing contraction in the axial surface. The deviations were smaller in order of occlusal plane, horizontal plane of margin and axial plane. Within the limited boundary of this study, the digital model obtained from stone model scan showed smaller deviation than the digital model obtained from impression scan.