Evaluating the influence of ambient light on scanning trueness, precision, and time of intra oral scanner

J Prosthodont Res. 2018 Jul;62(3):324-329. doi: 10.1016/j.jpor.2017.12.005. Epub 2018 Feb 1.


Purpose: This study evaluated the influence of illuminance and color temperature of ambient light on the trueness, precision, and scanning time of a digital impression.

Methods: Master data were acquired with a high-accuracy coordinate-measuring machine. The illuminance of ambient light was set at 0lux, 500lux, and 2500lux with a light-emitting diode (LED). Using a conversion filter, the color temperature was set at 3900 Kelvin (K) (yellow), 4100K (orange), 7500K (white), and 19,000K (blue). There were thus a total of 12 possible lighting conditions. The reference model was scanned five times under each condition by an intraoral scanner. Trueness was calculated as the mean difference between the master data and experimental data. Precision was calculated as the mean difference between the repeated scans in each test group. Statistical analysis was performed with two-way analysis of variance (ANOVA) and post hoc Tukey's multiple comparison test. The significance level was 0.05.

Results: For trueness, the mean deviation was significantly lower at 500lux than at 0lux and 2500lux. At 500lux, the mean deviation was significantly lower at 3900K than at other temperatures. Regardless of the color temperature, the scanning time was significantly longer at 2500lux than at other illuminance levels.

Conclusions: The 3900K and 500lux condition is the most appropriate lighting condition for taking a digital impression. This condition is typical of clinical settings. High illuminance ambient light increased the scanning time.

Keywords: Ambient light; Computer-aided design/computer-aided manufacturing; Digital impression; Precision; Trueness.

MeSH terms

  • Color
  • Computer-Aided Design*
  • Dental Impression Technique*
  • Dental Models
  • Light*
  • Lighting
  • Temperature