- 期刊
Accuracy of an inverted scanning technique used with an intraoral scanner: a pilot study
摘要
Introduction: The two main difficulties in using intraoral scanners (IOS) are the accuracy of full-mouth impressions and the need for gingival retraction. However, the methods traditionally used for gingival retraction may not meet the needs of IOS. The concept of using an IOS to conduct inverted scanning of a polyvinyl siloxane (PVS) impression was proposed to overcome this limitation. However, the accuracy of this technique and concept still requires verification. Therefore, the purpose of this study was to provide such verification. Materials and methods: A 3DP acrylonitrile butadiene styrene (ABS) maxillary model with tooth 21 crown preparation and 0.5mm width gingival sulcus was used as the standard model. This standard model was scanned with a tabletop scanner (TS) and an IOS to obtain TS and IOS digital standard models. Five PVS impressions of the standard model were made, and each PVS impression was scanned using the IOS three times without powdering and three times with powdering. The results of the inverted PVS impression scanning were then superimposed on the TS and IOS digital standard models. Results: The accuracy levels of the inverted scanning based on the TS model with and without powdering were 35.6± 4.9µm and 42.7± 5.0µm, respectively. The accuracy levels of the inverted scanning based on the IOS model with and without powdering were 21.8± 4.1µm and 31.7± 8.5µm, respectively. The inverted scanning technique presented the best accuracy (22.1± 3.0µm) when intraoral scanning was used without powdering in the marginal area. Conclusion: The inverted scanning technique's accuracy is clinically acceptable, and it provides the most accurate results when intraoral scanning is used without powdering in the marginal area.