Accuracy of 3D Printed Models Created by Two Technologies of Printers with Different Designs of Model Base

Abstract

Purpose To evaluate the accuracy of three‐dimensional (3D) printed models manufactured using two different printer technologies with different model base designs. Materials and Methods A maxillary typodont was scanned using a desktop scanner to generate the Standard Tessellation Language (STL) file as a reference scan. After the scanning procedure, the STL file was exported to Model Builder™ for designing the following two types of the model bases: a solid base design and a hollow base design with a 2.0 mm thickness of the external shell. Each design was printed to produce 10 models using a Continuous Liquid Interface Production (CLIP) printer and a Digital Light Processing (DLP) printer. The following four groups were tested: CLIP with solid base (CS); CLIP with hollow base (CH); DLP with solid base (DS); and DLP with hollow base (DH). A total of 40 models were scanned using the same desktop scanner to generate the STL files for evaluation of the accuracy by evaluation of trueness and precision. All STL files were superimposed with the control STL file via surface matching software and a comparison was performed using the 3D color mapping function and a 2D comparison of 48 points selected on the tested model. The data were collected by measuring the deviation between the tested model and the reference scan. Trueness was calculated by using the comparison among four tested groups. The Kruskal‐Wallis analysis was conducted to assess the overall statistical significance of differences among the tested groups (α = 0.05). For precision measurement, the evaluation was conducted using Intraclass Correlation Coefficient (ICC) value at 95% confident interval to determine the deviation within the same tested groups. Results The median values for the deviated distance of the four tested groups were 0.045 (CH), 0.035 (CS), 0.077 (DH), and 0.077 mm (DS). There were no statistically significant differences between the trueness of the two groups when using the same printers regardless of the designs of model base (p > 0.05). However, when comparing the two printers using the same model base design and the two different designs of model base, there were statistically significant differences in trueness (p < 0.05). The 3D printed models created using CLIP technology had higher trueness than the DLP technology printer. Precision of the 3D printed model was displayed in ICC value. The ICC values of four tested groups were 0.968 (CH), 0.981 (CS), 0.969 (DH), and 0.983 (DS). All tested groups were classified as exhibiting an excellent level of precision based on 95% confident interval of the ICC estimation. Conclusions The accuracy of 3D printed models was affected by the printer technology regardless of whether the model base was solid or hollow. The CLIP technology printer produced significantly less variation from the reference model than the DLP printer. However, all of the 3D printed models were determined to exhibit a clinically acceptable level of accuracy based on the recorded dimensions being less than 100 µm diffe...

Accuracy of 3-Dimensionally Printed Full-Arch Dental Models: A Systematic Review

“…Twenty-four studies included reference models as controls in their methodology design [ 6 , 7 , 34 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 55 , 56 , 57 ]. The controls included were a dental stone cast ( n = 8), a digital STL image of a dental stone cast ( n = 3), typodont digital STL image ( n = 7), typodont ( n = 1), prefabricated resin model digital STL image ( n = 2), patient intraoral scan image (2) or a dry human skull ( n = 1).…”

“…The specified printing layer thickness (z-axis resolution) substantially varied amongst studies and ranged from 25–150 μm for SLA, 20–100 μm for DLP, 16–32 μm for MJ, 100–150 μm for FFF and 89–102 μm for BJ. The study using CLIP technology did not specify the layer thickness used [ 53 ]. Most studies did not specify the printing resolution in the x- and y-axes.…”

“…MJ technology used photopolymers resins (acrylates) in liquid form and BJ technology used polylactic acid powder. Eleven studies did not specify the material used for the corresponding technology [ 19 , 35 , 36 , 40 , 44 , 45 , 48 , 52 , 53 , 54 , 55 ]. Within the studies assessing stone models, four used Type IV dental stone [ 6 , 35 , 40 , 45 ], one used Type III dental stone [ 4 ] and one did not specify the stone type utilised [ 34 ].…”

“…The three types of base designs used in the studies were horseshoe-shaped bases [ 4 , 34 , 36 , 37 , 38 , 39 , 41 , 43 , 49 , 50 , 51 , 55 ], regular American Board of Orthodontics (ABO) [ 35 , 38 , 44 , 46 , 47 , 49 , 52 , 54 , 57 ] and horseshoe-shaped with a transverse supporting bar [ 7 , 38 , 48 , 53 ]. Six studies did not specify their base design [ 6 , 19 , 40 , 42 , 45 , 56 ].…”

“…Six studies did not specify their base design [ 6 , 19 , 40 , 42 , 45 , 56 ]. Filling patterns employed in these studies were predominantly solid; however, hollow shelled [ 53 , 55 ] and honeycomb [ 37 ] were also utilised.…”