Effect of Different Preparation Depths for an Inlay‐Retained Fixed Partial Denture on the Accuracy of Different Intraoral Scanners: An In Vitro Study

Abstract

Purpose The aim was to evaluate the effect of different preparation depths for inlay‐retained fixed partial dentures on the accuracy of intraoral scanners. Materials and Methods Tooth preparations for two inlay‐retained fixed partial dentures were done and divided according to depth of the preparation. Group A: 2 mm pulpal floor depth, 3 mm gingival floor depth and Group B: 3 mm pulpal floor depth, 4mm gingival floor depth. The CEREC Omnicam 4.4.4, Omnicam 4.6.2. Trios3 and Medit i500 intraoral scanners were used in this study. Tooth preparations were scanned by each scanner 10 times. The STL files obtained from the intraoral scanners were compared to the reference models (trueness) and within each test group (precision) using a 3D comparison software. Data were then statistically analyzed. Results Regarding trueness, two‐way ANOVA revealed significant differences between the different types of scanners (p < 0.001) (Omnicam 4.4.4: 65.09 ± 2.87 Omnicam 4.6.1: 52.73 ± 3.31 Medit i500: 58.45 ± 2.63 Trios 3: 41.79 ± 4.42). Preparation depth had no significant influence on the trueness (p = 0.083). For precision two‐way ANOVA revealed significant differences between the different types of scanners (p < 0.001). Preparation depth had no significant influence on the precision (p = 0.111). Statistically significant interactions were found between the different variables. Conclusions The depth of preparation did not have an influence on the accuracy of different scanners. However, the type of scanner influenced the accuracy of digital impressions with Trios3 showing the highest accuracy.

Effect of preparation type on the accuracy of different intraoral scanners: An in vitro study at different levels of accuracy evaluation

“…This superiority was observed by several earlier studies, [11][12][13] and was attributed to the confocal microscopy scanning mechanism of TS, which is assumed to be a more accurate triangulation-based mechanism of MT and OC. [11][12][13] However, this is negated by other studies that did not show similar accuracy patterns. [1][2][3]24 Nevertheless, the TS may have the advantages of being a relatively newer system than the other IOS systems, which may have contributed to easier scanning, more userfriendliness, superior hardware, scanning time, and image resolution.…”

“…The comparison among the different IOS systems indicated that the TS was clearly more precise than MT and OC, respectively. This superiority was observed by several earlier studies, 11–13 and was attributed to the confocal microscopy scanning mechanism of TS, which is assumed to be a more accurate triangulation‐based mechanism of MT and OC 11–13 . However, this is negated by other studies that did not show similar accuracy patterns 1–3,24 .…”

“…Several studies have confirmed the accuracy of IOS systems for multiple applications 1–8 . However, despite the abundance of studies on the accuracy of IOS systems, there is considerable disparity in their designs 9–12 . The variations can be related to the scanning span, the number of units, scanned substrate material and design, and the condition of the scanned teeth 10 .…”

“… 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 However, despite the abundance of studies on the accuracy of IOS systems, there is considerable disparity in their designs. 9 , 10 , 11 , 12 The variations can be related to the scanning span, the number of units, scanned substrate material and design, and the condition of the scanned teeth. 10 One of the features that have not been fully investigated is the implication of tooth preparation type on the accuracy of IOS.…”

A guide for maximizing the accuracy of intraoral digital scans: Part 2—Patient factors

“…The higher the depth of the pulpal and gingival floors of a tooth preparation, the higher the discrepancy or lower scanning accuracy values reported. 33,35 The finish line location of a tooth preparation significantly affects the scanning accuracy values (Figure 2). 25,28,31 Therefore, the apicocoronal position of the tooth preparation finish line may impact the accuracy of the intraoral digital acquisition procedure.…”