Implant Prosthodontic Discrepancy of Complete-Arch Co-Cr Implant Frameworks Manufactured Through Selective Laser Melting Additive Manufacturing Technology Using a Coordinate Measuring Machine

PURPOSE The objective was to measure the implant prosthodontic discrepancy of complete-arch implant-supported frameworks made of cobalt-chromium (Co-Cr) fabricated using selective laser melting (SLM) additive manufacturing technologies. MATERIALS AND METHODS A completely edentulous maxillary cast with seven implant replicas was obtained. Co-Cr SLM frameworks (n = 9) from three different providers (SLM-1, SLM-2, SLM-3) were manufactured. A coordinate measuring machine was selected to measure the implant prosthodontic discrepancy (μm) on the x-, y-, and z-axis and the 3D gap (3D = √x$^{2}$+ y$^{2}$+z$^{2}$) where implants were considered as the statistical unit (n = 7). One-way analysis of variance (ANOVA), Student-Newman-Keuls, and Tukey tests were used to analyze the data (α = .05). RESULTS The mean 3D implant prosthodontic discrepancy (μm) was higher for SLM-1 (73.77 ± 27.94) than for SLM-2 (47.54 ± 22.63) and SLM-3 (47.26 ± 22.57). At the x-axis, SLM-2 showed a significantly smaller gap (16.21 ± 9.6) than SLM-3 (32.92 ± 27.77) and SLM-1 (34.77 ± 21.85). At the y-axis, however, SLM-3 presented a significantly smaller gap (27.97 ± 9.49) than SLM-2 (38.84 ± 27.82) and SLM-1 (54.35 ± 29.89). Similarly, at the z-axis, SLM-3 (4.01 ± 2.29) showed the least gap, followed by SLM-2 (9.09 ± 7.63), being significantly smaller than that of SLM-1 (16.14 ± 21.09). CONCLUSION The three SLM additive manufacturing technologies tested showed implant prosthodontic discrepancies ranging from 4.01 to 54.35 μm, which could be considered in the clinically acceptable range. Distortion at the z-axis was significantly less compared to x- and y-axes in all the groups tested