# Accuracy, Time, and Comfort of Different Intraoral Scanners: An In Vivo Comparison Study
###### Abstract  
Background: The purpose of this study was to compare the accuracy of three different intraoral scanners (IOSs) and to evaluate the patients' experience. Methods: Thirty subjects were scanned with three different IOSs (TRIOS Color(r), Itero Element 5D(r), and Itero Lumina(r)): a sample of 90 maxillary casts was collected. The inclusion criteria were permanent dentition, absence of defects during the dental impression, and complete record of the palatal vault. After the scanning procedure, patients were asked to answer a questionnaire (10 answers, scale from 1 to 10) to compare their experiences with Itero Element and Itero Lumina in the scanning procedure. Results: Differences were recorded in the upper central incisor region (f-ratio of 4.186 for Mesiodistal 1.1 and f-ratio of 4.222 for Mesiodistal 2.1, \(p\) < 0.05), while intercanine width Upper 13-23 showed the smallest f-ratio (0.226) when compared to the other results, followed by Mesiodistal 1.4 (0.433). Patients reported more comfort, less pain, decreased duration, and a better technology visualization of the impression with Itero Lumina. No significant differences concerning dryness of the mouth and gag reflex were found. Conclusions: The examined IOSs offer comparable accuracy in capturing dental arch dimensions. The interviewed patients expressed an overall preference for digital impressions performed with Itero Lumina, linked to increased comfort, painless practice, and a better technology visualization of the impression.  
digital dentistry; digital cast analysis; clinical practice; digital impressions +
Footnote †: journal: MedicalOptical impressions created with IOSs offer numerous advantages, making their adoption in clinical practice increasingly essential. These benefits include a reduced gag reflex, shorter working time, elimination of distortion from impression materials or gypsum, improved communication with patients and dental laboratories, and easy reproducibility [6, 7].  
In orthodontics, the adoption of digital workflows and impressions has become prevalent. This is partly due to the high incidence of orthodontic treatments among children, who are generally less cooperative than adults, and partly because certain orthodontic devices, such as aligners, are fabricated from digital impressions, allowing dentists to save time and reduce costs. For many patients, traditional impression-taking is one of the most stressful aspects of dental treatment, making digital impressions a more appealing option [8].  
A recent review compared traditional and digital impressions, revealing that nearly all studies reported a patient preference for digital technology over conventional methods. This preference is largely attributed to the greater efficiency of the intraoral scanning procedure, particularly regarding the time required to capture the impression [9].  
Several studies [10, 11, 12] have evaluated the performance of IOSs both in vivo and in vitro, concluding that intraoral scanners can accurately reproduce 3D dental models. Their accuracy is clinically adequate compared to traditional impression techniques, as assessed through two-dimensional linear measurements [13, 14].  
Therefore, the present study aims to compare the accuracy of three different intraoral scanners (IOSs) and to evaluate patients' experiences with digital impression techniques.