In vivo precision of conventional and digital methods for obtaining quadrant dental impressions

Abstract

OBJECTIVES Quadrant impressions are commonly used as alternative to full-arch impressions. Digital impression systems provide the ability to take these impressions very quickly; however, few studies have investigated the accuracy of the technique in vivo. The aim of this study is to assess the precision of digital quadrant impressions in vivo in comparison to conventional impression techniques. MATERIALS AND METHODS Impressions were obtained via two conventional (metal full-arch tray, CI, and triple tray, T-Tray) and seven digital impression systems (Lava True Definition Scanner, T-Def; Lava Chairside Oral Scanner, COS; Cadent iTero, ITE; 3Shape Trios, TRI; 3Shape Trios Color, TRC; CEREC Bluecam, Software 4.0, BC4.0; CEREC Bluecam, Software 4.2, BC4.2; and CEREC Omnicam, OC). Impressions were taken three times for each of five subjects (n = 15). The impressions were then superimposed within the test groups. Differences from model surfaces were measured using a normal surface distance method. Precision was calculated using the Perc90 1 0value.T hevaluesf oralltestgroupswerestatisticallycompared.RESU LT ST heprecisionrangedf rom18.8(CI) ABSTRACTObjectives: Quadrant impressions are a commonly used alternative to full-arch impressions. Digital impression systems provide the ability to take these impressions very quickly; however, few studies have investigated the accuracy of the technique in vivo. The aim of this study is to assess the precision of digital quadrant impressions in vivo in comparison to conventional impression techniques Materials and Methods: Impressions were obtained via two conventional (metal full-arch tray, CI and triple tray, T-Tray) and seven digital impression systems (Lava True Definition Scanner, T-Def; Lava Chairside Oral Scanner, COS; Cadent iTero, ITE; 3Shape Trios, TRI; 3Shape Trios Color, TRC; CEREC Bluecam, Software 4.0, BC4.0; CEREC Bluecam, Software 4.2, BC4.2; and CEREC Omnicam, OC). Impressions were taken three times for each of five subjects (n = 15). The impressions were then superimposed within the test groups. Differences from model surfaces were measured using a normal surface distance method. Precision was calculated using the Perc90_10 value. The values for all test groups were statistically compared. Results: The precision ranged from 18.8 µm (CI) to 58.5 µm (T-Tray), with the highest precision in the CI, T-Def, BC4.0, TRC, and TRI groups. The deviation pattern varied distinctly depending on the impression method. Impression systems with single-shot capture exhibited greater deviations at the tooth surface whereas high-frame-rate impression systems differed more in gingival areas. Triple tray impressions displayed higher local deviation at the occlusal contact areas of upper and lower jaw. Conclusions:Digital quadrant impression methods achieve a level of precision, comparable to conventional impression techniques. However there are significant differences in terms of absolute values and deviation pattern.Clinical Relevance: With all tested digital impression sys...

Precision of guided scanning procedures for full-arch digital impressions in vivo

“…The larger the scanned areas, the more susceptible to scanning errors the intraoral scanning system performs. This observation is in agreement with recently published literature referring to the accuracy for obtaining digital quadrant and full-arch impressions [4,9,14]. The deviation pattern observed for both digital impression systems in this study was similar to what has been described in the literature [4,9].…”

“…Only a few studies are available regarding the accuracy of digital impressions in-vivo [4,9]. According to ISO 5725-1 standardization, accuracy is characterized by the terms trueness and precision [8].…”

“…To obtain a highly accurate model, an ideal matching of single images is required for intraoral scanning systems. In literature, intraoral scanning devices have been shown to perform more accurately for smaller areas such as quadrants [4,9]. The main indication for orthodontic issues is the full-arch impression [12].…”

Trueness of four different milling procedures used in dental CAD/CAM systems

“…The evaluation method used is bound to the scan accuracy of the extra-oral scanner. Characteristics, such as depth, steepness and multiple-angled curvatures, may influence scan accuracy, as values for scan accuracy can vary substantially, depending on the system used and the geometry of the scanned item [5,41]. However, the geometric conditions were the same for all groups and should not have affected the scanning accuracy between the groups.…”

Accuracy of four intraoral scanners in oral implantology: a comparative in vitro study

“…To date, IOS are used to obtain study models [11], in prosthesis for the detection of impressions necessary for the modeling and fabrication of a whole series of restorations (single crowns [12], fixed partial dentures [13, 14], and in selected cases, complete fixed arches [15]), but also in the surgical field (integrated in acquisition procedures in guided surgery) [16] and in orthodontics (for the fabrication of aligners and different customized orthodontic devices) [17]. …”