Digital evaluation of the reproducibility of implant scanbody fit—an in vitro study

Abstract

Dental restorations are increasingly manufactured by CAD/CAM systems. Currently, there are two alternatives for digitizing dental implants: direct intra-oral data capturing or indirect from a master cast, both with transfer caps (scanbodies). The aim of this study was the evaluation of the fit of the scanbodies and their ability of reposition. At the site of the first molars and canines, implants were placed bilaterally in a polymer lower arch model (original model), and an impression was taken for fabricating a stone cast (stone model). Ten white-light scans were obtained from the original and the stone model with the scanbodies in place. The scanbodies were retrieved after each scan and re-attached to the same implant or lab analogue. The first scan of the series served as control in both groups. The subsequent nine scans and control were superimposed using inspection software to identify the discrepancies of the four scanbodies in both experimental groups. The systematic error of digitizing the models was 13 μm for the polymer and 5 μm for the stone model. The mean discrepancy of the scanbodies was 39 μm (±58 μm) on the original implants versus 11 μm (±17 μm) on the lab analogues. The difference in scanbody discrepancy between original implants and lab analogues was statistically significant (p < 0.05, Mann-Whitney U test). Scanbody discrepancy was higher on original implants than on lab analogues. Fit and reproducibility of the scanbodies on original implants should be improved to achieve higher accuracy of implant-supported CAD/CAM fabricated restorations.

Performance of dental impression materials: Benchmarking of materials and techniques by three-dimensional analysis

“…Also, there is no need for a shape restriction when freeform surfaces can be analyzed just as well as clearly geometrically defined shapes such as cones or cylinders. The assessment of many different experimental set-ups close to the dental clinical setting hence becomes possible [2][3][4]8,37,[45][46][47]49,57,58) . Based on the experience from former in vitro and in vivo studies 3,9,[45][46][47][48]53,57) , maximum positive and negative deviations, which are also calculated by the CAD software, were not further evaluated.…”

“…Data can be acquired from different sources, such as non-contact optical digitizing, mechanical digitizing, or data from more complex medical imaging methods (e.g., computer tomography and magnetic resonance tomography). Such data and data captured at different times must be aligned from the relative measuring orientation into a common coordinate system before any analysis may be initiated [1][2][3][4] . Different impression materials for study models used in orthodontic treatment planning may be analyzed using cone-beam computer tomography data of the impressions 5) with sufficient precision for orthodontic means.…”

“…Distance measurements of arches and abutments are also used for the analysis of factors other than the impression material itself: impression technique [22][23][24][25][26][27] , impression tray 28,29) , material volume [30][31][32] , or the effect of using a surfactant prior to pouring an impression 33) . Even when 3D digital data are used, the following analysis is often reduced to two-dimensional (2D) distance measurements 4,34) . This type of analysis implies a loss of information and may not account for the variability of dimensional accuracy as it relates to measurement site 35) .…”

Technical Report: Precisely Fitting Bars on Implants in Five Steps—A CAD/CAM Concept for the Edentulous Mandible

“…13 A special scan body with patented geometry as well as patented surface coating was used for this patient (Figs 3 and 4). …”

Análise da precisão de uma nova moldeira para implantes dentários

“…Assim, as diferentes ferramentas de análise têm sido utilizadas: microscópio óptico (Burns et al, 2003;Ceyhan et al, 2003;Cabral;Guedes, 2007;, microscópio eletrônico de varredura (Yamamoto et al, 2010), tomografia computadorizada (Tahmaseb et al, 2010), sistema CAD/CAM (Abduo et al, 2011;Papaspyridakos et al, 2011;Stimmelmayr et al, 2011a;Stimmelmayr et al, 2011b) entre outros (Conrad et al, 2007;Sorrentino et al, 2010;Kwon et al, 2011;Cho, 2011 (Jemt et al, 1992;Kallus;Bessing, 1994;Burns et al, 2003).…”