Digital evaluation of the accuracy of implant scanbody

Abstract

Objectives: To evaluate the accuracy of implant scanbodies made of PEEK and aluminium using the standard virtual alignment method. Methods: A master model of edentulous maxillary jaw with 6 multi-unit abutment replicas was fabricated. Scanbodies made of PEEK and aluminium were inserted into the model and scanned by their corresponding scanners (Medit T300 and 3Shape D2000). The scanbodies were then removed and re-attached randomly before another scan and a total of 5 scans were performed. The scanned images (reference group) were virtually aligned with the default images of scanbodies in the library using a computer-aided design software (EXOCad) (test group). Data were then analyzed by an inspection software (Geomagic Control). All datasets were superimposed and evaluated using a combined method (characteristics registration + best-fit-algorithm). Two sample T-test was used to analyze the differences in 3D deviation of the scanbodies (trueness) between the reference and test datasets. The level of significance was set to .05. Results: Regarding the accuracy of alignment on implant level (single scan body), no significant difference in angular error was found between the PEEK (0.1±0.1°) and aluminium group (0.1±0.1°) (P>0.05) but greater 3D error was noted in the aluminium group (122.7±56.2 µm) comparing with the PEEK group (52.7±18.0 µm) (P<0.05). Regarding the accuracy of prosthesis level (full-arch scan bodies), no significant difference in angular error was found between the PEEK (0.1±0.1°) and aluminium group (0.1±0.1°) (P>0.05) but significantly greater distance error was noticed in the aluminium group (90.5±81.1 um) than the PEEK group (36.7±33.8 um) (P<0.05). Conclusions: Tested PEEK implant scan bodies appeared to be more accurate than the aluminium ones using their corresponding scanner systems.