Related Experiment Video
Updated: Mar 14, 2026
Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision
Published on: April 29, 2014
Accuracy of single-abutment digital cast obtained using intraoral and cast scanners
Jae-Jun Lee1, Ii-Do Jeong2, Jin-Young Park2
1Graduate student, Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea.
Statement Of Problem:
Scanners are frequently used in the fabrication of dental prostheses. However, the accuracy of these scanners is variable, and little information is available.
Purpose:
The purpose of this in vitro study was to compare the accuracy of cast scanners with that of intraoral scanners by using different image impression techniques.
Material And Methods:
A poly(methyl methacrylate) master model was fabricated to replicate a maxillary first molar single-abutment tooth model. The master model was scanned with an accurate engineering scanner to obtain a true value (n=1) and with 2 intraoral scanners (CEREC Bluecam and CEREC Omnicam; n=6 each). The cast scanner scanned the master model and duplicated the dental stone cast from the master model (n=6). The trueness and precision of the data were measured using a 3-dimensional analysis program. The Kruskal-Wallis test was used to compare the different sets of scanning data, followed by a post hoc Mann-Whitney U test with a significance level modified by Bonferroni correction (α/6=.0083). The type 1 error level (α) was set at .05.
Results:
The trueness value (root mean square: mean ±standard deviation) was 17.5 ±1.8 μm for the Bluecam, 13.8 ±1.4 μm for the Omnicam, 17.4 ±1.7 μm for cast scanner 1, and 12.3 ±0.1 μm for cast scanner 2. The differences between the Bluecam and the cast scanner 1 and between the Omnicam and the cast scanner 2 were not statistically significant (P>.0083), but a statistically significant difference was found between all the other pairs (P<.0083). The precision of the scanners was 12.7 ±2.6 μm for the Bluecam, 12.5 ±3.7 μm for the Omnicam, 9.2 ±1.2 μm for cast scanner 1, and 6.9 ±2.6 μm for cast scanner 2. The differences between Bluecam and Omnicam and between Omnicam and cast scanner 1 were not statistically significant (P>.0083), but there was a statistically significant difference between all the other pairs (P<.0083).
Conclusions:
An Omnicam in video image impression had better trueness than a cast scanner but with a similar level of precision.
