Accuracy of Digital vs Conventional Implant Impression Approach: A Three-Dimensional Comparative In Vitro Analysis

Abstract

Purpose: To assess the three-dimensional (3D) accuracy and clinical acceptability of implant definitive casts fabricated using a digital impression approach and to compare the results with those of a conventional impression method in a partially edentulous condition. Materials and Methods: A mandibular reference model was fabricated with implants in the first premolar and molar positions to simulate a patient with bilateral posterior edentulism. Ten implant-level impressions per method were made using either an intraoral scanner with scanning abutments for the digital approach or an open-tray technique and polyvinylsiloxane material for the conventional approach. 3D analysis and comparison of implant location on resultant definitive casts were performed using laser scanner and quality control software. The inter-implant distances and interimplant angulations for each implant pair were measured for the reference model and for each definitive cast (n = 20 per group); these measurements were compared to calculate the magnitude of error in 3D for each definitive cast. The influence of implant angulation on definitive cast accuracy was evaluated for both digital and conventional approaches. Statistical analysis was performed using t test (α = .05) for implant position and angulation. Clinical qualitative assessment of accuracy was done via the assessment of the passivity of a master verification stent for each implant pair, and significance was analyzed using chi-square test (α = .05). Results: A 3D error of implant positioning was observed for the two impression techniques vs the reference model, with mean ± standard deviation (SD) error of 116 ± 94 μm and 56 ± 29 μm for the digital and conventional approaches, respectively (P = .01). In contrast, the inter-implant angulation errors were not significantly different between the two techniques (P = .83). Implant angulation did not have a significant influence on definitive cast accuracy within either technique (P = .64). The verification stent demonstrated acceptable passive fit for 11 out of 20 casts and 18 out of 20 casts for the digital and conventional methods, respectively (P = .01). Conclusion: Definitive casts fabricated using the digital impression approach were less accurate than those fabricated from the conventional impression approach for this simulated clinical scenario. A significant number of definitive casts generated by the digital technique did not meet clinically acceptable accuracy for the fabrication of a multiple implant-supported restoration.

The effect of scanning the palate and scan body position on the accuracy of complete‐arch implant scans

“…Conventional impression techniques require several clinical and laboratory steps, which could introduce flaws . The developments in digital technology give clinicians the option to digitally scan the structures . While the accuracy of various implant impression techniques has been the subject of several studies and many techniques have been reported both in conventional and digital implant scans, there are conflicting reports regarding the superiority of the impression technique's accuracy .…”

“…The developments in digital technology give clinicians the option to digitally scan the structures . While the accuracy of various implant impression techniques has been the subject of several studies and many techniques have been reported both in conventional and digital implant scans, there are conflicting reports regarding the superiority of the impression technique's accuracy . Some studies reported that the accuracy of digital implant scans are comparable with conventional impressions …”

Accuracy of printed casts generated from digital implant impressions versus stone casts from conventional implant impressions: A comparative in vitro study

“…A systematic review found that digital impressions resulted in better marginal and internal fit than conventional for tooth-supported single crowns and FDPs (Chochlidakis et al, 2016). Regarding implant-supported prostheses, there are less available data currently, but there is a constant increase of published data on the accuracy of digital impressions with IOS systems, and the results seem promising for both partially and fully edentulous arches (Amin et al, 2017;Basaki, Alkumru, Souza, & Finer, 2017;Chew et al, 2017;Chia et al, 2017;Lee, Betensky, Gianneschi, & Gallucci, 2015;Marghalani et al, 2018;Papaspyridakos et al, 2016;Papaspyridakos, Rajput, Kudara, & Weber, 2017;Vandeweghe, Vervack, Dierens, & Bruyn, 2017).…”

Immediate loading of multiple splinted implants via complete digital workflow: A pilot clinical study with 1‐year follow‐up

“…However, in a recent clinical study with 36 partial edentulous patients, digital impression exhibited least accuracy with linear errors ranging from 160 to 270 μm, and the authors conclude it is not suitable to fabricate a well‐fitting restoration with digital impressions . An in vitro study also supported this conclusion . The inconsistency of these results might be caused by various factors, such as different number and distribution of implants, types of intraoral scanning system, choice of digitalization methods, reference data, and evaluation methods.…”

“…36 An in vitro study also supported this conclusion. 37 The inconsistency of these results might be caused by various factors, such as different number and distribution of implants, types of intraoral scanning system, choice of digitalization methods, reference data, and evaluation methods. Until now, no consensus can be made regarding digital impression in fabricating multiple-implant-supported restoration.…”