(1) Background: This in-vitro study was designed to investigate the accuracy of CAD/CAM fabricated occlusal devices with different heights and volumes. (2) Methods: Based on an intraoral scan, an occlusal device with a vertical bite elevation of 2.5 mm and 4.5 mm was digitally designed and 3D printed 10 times. The fabricated occlusal devices were digitized by an industrial structured light scanner (ILS) and provided in stl-format as test objects. The test objects were superimposed with the design dataset as reference to evaluate the accuracy of complete surfaces ([2.5_TOTAL] and [4.5_TOTAL]) with respect to their internal surfaces ([2.5_INTERNAL] and [4.5_INTERNAL]). The mean trueness and precision were calculated based on absolute mean deviation. Absolute and relative volume differences between reference and test were computed. Statistical significances were analyzed performing the Wilcoxon test (α =0.05). (3) Results: As absolute mean deviation trueness values were obtained: 59 ± 5 µm for [2.5_INTERNAL], 98 ± 9 µm for [4.5_INTERNAL], 68 ± 1 µm for [2.5_TOTAL] and 90 ± 10 µm for [4.5_TOTAL]. The precision applying absolute mean deviation was 14 ± 8 µm for [2.5_INTERNAL], 22 ± 11 µm for [4.5_INTERNAL], 19 ± 10 µm for [2.5_TOTAL] and 26 ± 13 µm for [4.5_TOTAL]. The mean trueness and precision values differed significantly. Volume differences of 2.11% for [4.5_TOTAL] and of 2.35% for [2.5_TOTAL] in comparison to their reference file were evaluated. (4) Conclusions: Printed occlusal devices with minor height and volume were more accurate. Both types of devices exhibited results that were comparable to the literature.

This in-vitro study aimed to investigate whether intraoral scanners (IOS) are suitable for wear measurement compared to optical profilometry (WLP). A zirconia cast representing the teeth (24–28) was fabricated. It was digitized six times using three different intraoral scanners, Cerec Omnicam AC (OC), Trios 3 (Tr3), and True Definition (TD). The scans were conducted at baseline (t0) and at three different stages of simulated wear (t1–t3), each at one wear-facet on FDI 26 and FDI 27. WLP was used as a reference method. Within each acquisition system, the maximum wear at each facet was analyzed by superimposing the STL data of t0 with t1–t3. A power analysis was performed (G*Power), and the Wilcoxon-signed-rank-test was used to evaluate whether there were statistically significant differences between the groups (Bonferroni corrected) (α = 0.05). At wear-facet FDI 27, differences from +4% t1 TD up to +19% t2 OC, corresponding to a metric value of 8 µm and 45 µm, were measured. At FDI 26 deviations between −2% t1 Tr3, and +10% OC and Tr3, were observed. Considering some limitations, the IOS are a promising alternative to wear measurement based on WLP due to its simple application to capture surface changes in a reasonable and quick way.

This in-vitro study was designed to investigate whether conventionally produced casts and printed casts for orthodontic purposes show comparable full-arch accuracy. To produce casts, either a conventional impression or a digital data set is needed. A fully dentate all ceramic master cast was digitized with an industrial scanner to obtain a digital reference cast [REF]. Intraoral scans [IOS] and alginate impressions were taken from the master cast so that ten printed and ten gypsum casts were obtained. The printed casts [DLP] were digitized by an industrial scanner and as well as the gypsum casts [GYPSUM]. The following absolute mean trueness evaluations by superimposition were accomplished: [REF vs. GYPSUM]; [REF vs. DLP]; [REF vs. IOS]; [IOS vs. DLP]. For precision analysis the data sets of [GYPSUM], [IOS] and [DLP] were available. The absolute mean trueness values were 68 μm ± 15 μm for [REF vs. GYPSUM], 46 μm ± 4 μm for [REF vs. DLP], 20 μm ± 2 μm for [REF vs. IOS] and 41 μm ± 4 μm for [IOS vs. DLP]. [REF vs. GYPSUM] and [REF vs. DLP], [REF vs. IOS], [REF vs. DLP] and [IOS vs. DLP] showed statistically significant differences. The precision values were 56 μm ± 17 μm for [GYPSUM], 25 μm ± 9 μm for [DLP] and 12 μm ± 2 μm for [IOS] and differed significantly among each other. In the present study the print workflow revealed superior results in comparison to the conventional workflow. Due to contrary deviations in the [REF vs. IOS] and the [IOS vs. DLP] data sets the overall trueness deviations was enhanced.

This in vitro study was designed to investigate whether conventionally produced casts and printed casts for prosthodontic purposes show comparable full-arch accuracy; a ceramic reference cast with inlay and crown preparations was fabricated. Ten gypsum casts were fabricated from conventional silicone elastomeric impressions. Ten digital impressions [IOS] of the reference cast were obtained by an intraoral scanner to fabricate 3D-printed resin casts. The ceramic reference cast, the gypsum, and the printed casts were digitized by an industrial structured light scanner (ILS) and provided as stl files. To evaluate absolute mean trueness values, the digitized gypsum casts [CON], digitized printed casts [PRINT], and [IOS] were superimposed with the digitized ceramic reference cast [REF]. Additionally, each [IOS] scan was compared with its corresponding [PRINT]. The precision was calculated for [CON], [IOS], and [PRINT]. The Mann–Whitney U test for independent samples and the Wilcoxon test for connected samples were performed (p ≤ 0.05). As absolute mean deviation trueness values were obtained: 69 ± 24 µm for [REF]-[CON], 33 ± 4 µm for [REF]-[PRINT], and 19 ± 3 µm for [REF]-[IOS]. The superimposition [IOS]-[PRINT] revealed 38 ± 6 µm. The precision was 74 ± 22 µm for [CON], 32 ± 10 µm for [PRINT], and 15 ± 4 µm for [IOS]. With respect to the workflow, the trueness values of [REF]-[CON] and [REF]-[PRINT] differed significantly. Within the digital workflow, [REF]-[PRINT], [REF]-[IOS], and [IOS]-[PRINT], all values differed significantly. Within the limitations of the study, digital impression and printed cast fabrication were more accurate and reproducible than the conventional workflow.