This study aimed to evaluate the effects of natural light conditions and ambient lighting levels changing at different times of the day on the accuracy and duration of digital scans made with intraoral scanners in a clinical setting. A volunteer individual with full dentition without any restorations in the maxilla and mandible was included in this study. The reference model was created by digitizing the plaster model obtained with vinyl polysiloxane-based impression material with a 3Shape E4 laboratory scanner. In order to evaluate the effect of natural light, digital scans were performed three times a day in the morning (10:00), noon (14:00), and evening (19:00) for 5 days. All scans were performed in constant ambient conditions with the curtains half-closed and the clinical lighting on. Ambient light intensity was measured from two different points before each scan. The obtained digital models were compared with the reference models using Geomagic Control X software, and root mean square (RMS) values were recorded. In addition, the duration of each scan was recorded in seconds. Statistical analysis of the data was performed with the SPSS 28.0 program. The conformity of the parameters to normal distribution was evaluated with the Shapiro-Wilk test. Intergroup differences and correlation analyses were performed by selecting appropriate tests. The significance level was accepted as p < 0.05. In maxillary scans, significantly higher RMS values were obtained in the evening hours (p < 0.05), while in mandibular scans, no significant difference was found in RMS values for time periods. Negative and significant relationships were determined between maxillary and mandibular RMS values and room and headrest light levels (p < 0.05). A positive and significant relationship was found between room light level and maxillary scanning time. Significant relationships were also observed between both maxillary and mandibular scanning times and headrest light levels. It was observed that changing natural light levels at different times of the day could affect digital scanning accuracy, especially in complex anatomical regions such as the maxilla. In addition, it was determined that increasing lighting levels extended the scanning time. These findings reveal that providing ideal lighting conditions in digital scans is important both in terms of increasing accuracy and optimizing the processing time.
Turgut et al. (Wed,) studied this question.