From Alginate to Pixel: Comparing the Effect of Two Dental Impression Methods on Children’s Anxiety

Background/Objectives: Alginate dental impressions are often among the most anxiety-inducing procedures for pediatric patients due to discomfort caused by nausea, gagging, and the vomiting reflex. This technique frequently raises anxiety levels in children. In contrast, intraoral scanners are increasingly used in clinical practice and offer a more comfortable alternative. Physiological parameters such as heart rate (HR) and oxygen saturation (SpO2) are useful, objective indicators of anxiety. This study aimed to evaluate significant changes in HR and SpO2 during dental impression procedures using two techniques—an analog (alginate) and a digital (intraoral scanner) one—in both dental arches, to determine the method inducing the least anxiety. Methods: A non-interventional clinical study was conducted on a sample of 30 children. A fingertip pulse oximeter was used to measure HR and SpO2 during impression taking with alginate and with an intraoral scanner. Statistical analysis was performed using SPSS® (Version 30.0. Amonk, NY, USA: IBM Corp). Descriptive statistics (mean and standard deviation) were calculated, and the Friedman and Wilcoxon tests with Bonferroni correction were applied, using a 5% significance level. The study was approved by the Ethics Committee of the University of Murcia. Results: Alginate impressions produced a statistically significant increase in HR in both the upper [(19 ± 11) bpm] and lower [(18 ± 9) bpm] arches compared to the scanner [(7 ± 5) bpm and (7 ± 4) bpm, respectively] (χ2 = 49.30; p < 0.001). SpO2 levels also dropped more when using alginate for both the upper and lower arches [(−2 ± 2)% and (−2 ± 3)%, respectively] than when using the scanner [(−1 ± 1)% in both arches] (χ2 = 21.41; p < 0.001). Conclusions: Alginate impressions triggered a significant anxiety response, as evidenced by significant changes in HR and SpO2. Intraoral scanners were less invasive, as indicated by the greater proximity of the physiological parameters to the baseline values, making them a promising alternative in pediatric dentistry.