Comparison of intraoral and laboratory scanners to an industrial-grade scanner while analyzing the fabrication trueness of polymer and titanium complete-arch implant-supported frameworks

Abstract

Objectives: To compare the scans of different intraoral scanners (IOSs) and laboratory scanners (LBSs) to those of an industrial-grade optical scanner by measuring deviations of complete-arch implant-supported frameworks from their virtual design file. Material and methods: Ten polyetheretherketone (PEEK) and 10 titanium (Ti) complete-arch implant-supported frameworks were milled from a master standard tessellation language (STL) file. An industrial-grade blue light scanner (AT), 2 LBSs (MT and E4), and 3 IOSs (PS, T3, and T4) were used to generate STL files of these frameworks. All STLs were imported into an analysis software (Geomagic Control X) and overall root mean square (RMS) values were calculated. Marginal surfaces of all STL files were then virtually isolated (Medit Link v 2.4.4) and marginal RMS values were calculated. Deviations in scans of tested scanners were compared with those in scans of AT by using a linear mixed effects model (alpha = 0.05). Results: When the scans of PEEK frameworks were considered, PS and T3 had similar overall RMS to those of AT (p >= .076). However, E4 and T4 had higher and MT had lower overall RMS than AT (p <= .002) with a maximum estimated mean difference of 13.41 mu m. When the scans of Ti frameworks were considered, AT had significantly lower overall RMS than tested scanners (p <= .010) with a maximum estimated mean difference of 31.35 mu m. Scans of tested scanners led to significantly higher marginal RMS than scans of AT (p <= .006) with a maximum estimated mean difference of 53.90 mu m for PEEK and 40.50 mu m for Ti frameworks. Conclusion: Only the PEEK framework scans of PS and T3 led to similar overall deviations to those of AT. However, scans of all tested scanners resulted in higher marginal deviations than those of AT scans. Clinical Significance: Scans performed by using PS and T3 may be alternatives to those of tested reference industrial scanner AT, for the overall fabrication trueness analysis of complete-arch implant-supported PEEK frameworks.