Digitization of dental alginate impression: Three-dimensional evaluation of point cloud

The purpose of this study was to evaluate the digitization of alginate impressions by analyzing differences between the scan data of two types of impressions (alginate and rubber) taken from the master die and the scan data for the master die. The master die and impressions were digitized using a dental laser scanner (7 series, Dental Wings, Montreal, Canada). The crown portion of the abutment teeth in the digital data of 20 impressions was divided into three regions: cervical surface, middle surface, and occlusal surface. An independent t-test showed a significant difference (p<0.05) in the mean difference for each experimental group (alginate and rubber). One-way ANOVA and Tukey's honest significant difference test revealed a significant difference (p<0.05) among the three regions in the rubber impression. The results of this study also carefully suggest the possibility of digitization of alginate impressions in the future.