다양한 스캔바디를 이용한 디지털 인상의 정확성 비교

Abstract

Purpose : Various scan bodies, which are needed for intraoral or model scanning, were introduced for making implant abutment. There is still question about the accuracy of digital impression. So, the aim of this study is to evaluate the accuracy of digital scanning using 3 different scan bodies for the abutment level and fixture level digital impression.

Materials and methods : Two Implant fixtures(UFII, DIO Implant, Busan, Republic of Korea) were placed on #35, 36 missing area of acrylic dentiform model. 3 types of scan bodies (Digital abutment(DA), H-scan body(HS), Scan adapter(SA)) were connected to the implant fixtures. And then conventional and digital impression were performed. The control and experimental groups were the below. Control- DA were connected to the fixtures placed on the study model and scanned with model scanner (S600 ARTI model scanner, Zirkonzhan, South Tyrol, Italy). From the obtained digital model, DA digital data were extracted. Group 1- DA were connected to the fixtures placed on the study model and scanned with intraoral scanner (Trios®, T12A, 3 shape Trios A/S, Copenhagen, Denmark). From the obtained digital model, DA digital data were extracted. Group 2- DA were connected to the fixtures placed on the study model and impression was taken with silicone material. Gypsum models were fabricated and then scanned with model scanner. From the obtained digital model, DA digital data were extracted. Group 3- HS were connected to the fixtures placed on the study model and scanned with intraoral scanner. From the obtained digital model, virtual DA were connected and DA digital data were extracted. Group 4- HS were connected to the fixtures placed on the study model and impression was taken with silicone material. Gypsum models were fabricated and then scanned with model scanner. From the obtained digital model, virtual DA were connected and DA digital data were extracted. Group 5- SA were connected to the fixtures placed on the study model and scanned with intraoral scanner. From the obtained digital model, virtual DA were connected and DA digital data were extracted. DA STL files which were extracted from each experimental group, overlapped using 3D analysis program(Geomagic Design X 2014; 3D systems, USA). Trueness and precision were measured for the accuracy of the data. The measurement values through the 3D analysis were calculated using root mean square(RMS). To statistical analysis, Kruskal-Wallis test were performed.

Results : In the comparison of trueness (RMS: Mean±SD), experimental group 1 showed statistically different with groups 3,4,5 (p<0.005). In the Precision, there were statistically different between group 1 and 3,4,5 (p<0.005), and between groups 1 and 2, between groups 3 and 4 (p<0.005).

Conclusions : Within the limitations of this in vitro study, the digital impression taken by an intraoral scanner at abutment level showed higher trueness and precision than the digital impression made at the fixture level. All measurements value of digital impression showed clinically acceptable accuracy.