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

Abstract

Background: Until now, only a few studies have compared the ability of different intraoral scanners (IOS) to capture high-quality impressions in patients with dental implants. Hence, the aim of this study was to compare the trueness and precision of four IOS in a partially edentulous model (PEM) with three implants and in a fully edentulous model (FEM) with six implants.

Methods: Two gypsum models were prepared with respectively three and six implant analogues, and polyether-ether-ketone cylinders screwed on. These models were scanned with a reference scanner (ScanRider®), and with four IOS (CS3600®, Trios3®, Omnicam®, TrueDefinition®); five scans were taken for each model, using each IOS. All IOS datasets were loaded into reverse-engineering software, where they were superimposed on the reference model, to evaluate trueness, and superimposed on each other within groups, to determine precision. A detailed statistical analysis was carried out.

Results: In the PEM, CS3600® had the best trueness (45.8 ± 1.6μm), followed by Trios3® (50.2 ± 2.5μm), Omnicam® (58.8 ± 1.6μm) and TrueDefinition® (61.4 ± 3.0μm). Significant differences were found between CS3600® and Trios3®, CS3600® and Omnicam®, CS3600® and TrueDefinition®, Trios3® and Omnicam®, Trios3® and TrueDefinition®. In the FEM, CS3600® had the best trueness (60.6 ± 11.7μm), followed by Omnicam® (66.4 ± 3.9μm), Trios3® (67.2 ± 6.9μm) and TrueDefinition® (106.4 ± 23.1μm). Significant differences were found between CS3600® and TrueDefinition®, Trios3® and TrueDefinition®, Omnicam® and TrueDefinition®. For all scanners, the trueness values obtained in the PEM were significantly better than those obtained in the FEM. In the PEM, TrueDefinition® had the best precision (19.5 ± 3.1μm), followed by Trios3® (24.5 ± 3.7μm), CS3600® (24.8 ± 4.6μm) and Omnicam® (26.3 ± 1.5μm); no statistically significant differences were found among different IOS. In the FEM, Trios3® had the best precision (31.5 ± 9.8μm), followed by Omnicam® (57.2 ± 9.1μm), CS3600® (65.5 ± 16.7μm) and TrueDefinition® (75.3 ± 43.8μm); no statistically significant differences were found among different IOS. For CS3600®, For CS3600®, Omnicam® and TrueDefinition®, the values obtained in the PEM were significantly better than those obtained in the FEM; no significant differences were found for Trios3®.

Conclusions: Significant differences in trueness were found among different IOS; for each scanner, the trueness was higher in the PEM than in the FEM. Conversely, the IOS did not significantly differ in precision; for CS3600®, Omnicam® and TrueDefinition®, the precision was higher in the PEM than in the FEM. These findings may have important clinical implications.

Keywords: Accuracy; Intraoral scanners; Oral implants; Precision; Trueness.

Figures

Fig. 1

Two different gypsum models were prepared: a partially edentulous maxilla, with three implant analogues in positions #23, #24 and #26, and a fully edentulous maxilla, with the same implant analogues in positions #11, #14, #16, #21, #24 and #26

Fig. 2

Four different IOS (CS 3600®, Carestream, Rochester, NY, USA; Trios 3®, 3-Shape, Copenhagen, Denmark; Cerec Omnicam®, Sirona Dental System GmbH, Bensheim, Germany; True Definition®, 3M Espe, S. Paul, MN, USA) were compared in this study, with the purpose to investigate their trueness and precision in oral implantology

Fig. 3

Trueness in the partially edentulous maxilla, occlusal view. The best single result obtained with each device were: (a) CS 3600® 44 ± 44 μm; (b) Trios 3® 48 ± 52 μm; (c) Cerec Omnicam® 57 ± 66 μm; (d) True Definition® 57 ± 52 μm

Fig. 4

Trueness in the fully edentulous maxilla, occlusal view. The best single result obtained with each device were: (a) CS 3600® 50 ± 81 μm; (b) Trios 3® 57 ± 89 μm; (c) Cerec Omnicam® 63 ± 87 μm; (d) True Definition® 84 ± 89 μm

Fig. 5

Precision in the partially edentulous maxilla, occlusal view. The best single result obtained with each device were: (a) CS 3600® 19 ± 50 μm; (b) Trios 3® 21 ± 42 μm; (c) Cerec Omnicam® 25 ± 53 μm; (d) True Definition® 15 ± 28 μm

Fig. 6

Precision in the fully edentulous maxilla, occlusal view. The best single result obtained with each device were: (a) CS 3600® 51 ± 75 μm; (b) Trios 3® 24 ± 45 μm; (c) Cerec Omnicam® 50 ± 74 μm; (d) True Definition® 42 ± 44 μm