Comparison of measurements between intraoral scanned digital model and plaster model

Abstract

Objective The purposc of this study was to evaluate the linear measurements difference between 3-dimensional digital models obtained with an intraoral scanner (Trios,3Shape,Denmark) and those on the corresponding plaster models.Methods Intraoral scan,and polyvinyl silicone impression were made and poured with type IV dental stone for each of 30 subjects.Three-dimensional images were obtained on this scanner and analyzed by using the Rapidform 2006 (Inustechnology,Korea)The scanning time was registrated by the scanner simultaneously.Toothwidth,arch width,arch length,curve of Spee measurements on the intraoral scanned model were compared with those on the corresponding plaster models measured with a digital caliper directly.Paired t tests were used to evaluate measurement differences between the two kinds of models.Independent t tests were used to evaluate differences of scanning time and crowding between upper and lower jaw.The interclass correlation(ICC) was calculated to evaluate the rcproducibility of the intraoral scanned models.Results No statistically significant differences were found between the measurements made directly on the dental casts and on intraoral scanned models.scan time within the upper jaw (411.9+162.2) s is greater than the lower jaw (290.8-+-94.9) s,(P＜0.001).The interclass correlations were high.Conclusions No significant difference was found for the linear measurements between intraoral scanned digital model and plaster model,and the intraoral scanned model is expected to replace plaster model in the future. Key words: Digital model; Plaster model; Intraoral scan; Three-dimensional; reconstruction