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

Abstract

BackgroundUntil 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.MethodsTwo 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.ResultsIn 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®.ConclusionsSignificant 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.

Custom-Made Direct Metal Laser Sintering Titanium Subperiosteal Implants: A Retrospective Clinical Study on 70 Patients

“…Similar results were found by in 2009 by Kusek, who published a case report of a patient who was rehabilitated using a simplified surgical protocol involving laser surgery and stereolithography [39]. In the above papers, the subperiosteal implants were first fabricated by means of CAD/CAM technology (stereolithography) in epoxy resin; then, the resin implants were sent to a dental laboratory for fabrication of the cast frameworks [38, 39]. …”

“…The authors concluded that the advent of stereolithography as a new tool for modeling anatomy for subperiosteal implants and advances in computed tomography offer a higher degree of build accuracy and repeatability than was previously available [38]. Similar results were found by in 2009 by Kusek, who published a case report of a patient who was rehabilitated using a simplified surgical protocol involving laser surgery and stereolithography [39].…”

“…In 1998, McAllister and colleagues reported on the application of stereolithography for the fabrication of a subperiosteal implant [38]. The authors concluded that the advent of stereolithography as a new tool for modeling anatomy for subperiosteal implants and advances in computed tomography offer a higher degree of build accuracy and repeatability than was previously available [38].…”

“…The introduction of new acquisition methods (cone beam computed tomography (CBCT) [37] and intraoral scanners [38]), along with the spread of processing/elaboration such as computer-assisted-design/computer-assisted-manufacturing (CAD/CAM) software [39], new materials [40], and fabrication technologies, has dramatically changed the world of implant dentistry, opening up new perspectives.…”

Soft tissue replication in single unit implant impressions—A three dimensional clinical study

“…Digital impressions can minimize inaccuracies such as impression material strain, displacement of implant impression components and gypsum expansion, eliminating the need for conventional impression materials and making it faster and more comfortable for patients, although the high cost of investment is still a barrier to become a standard of care . The use of IOS allows for the immediate determination of the quality of the impression, with described values of trueness ranging from 44 to 64 microns (μm) and of precision from 16 to 27 μm, depending on the IOS used but well below the currently accepted threshold of 100‐120 μm of clinical deviation, being described as a comparable alternative to conventional impression methods …”