A focused simulation-based optimization of print time and material usage with respect to orientation, layer height and support settings for multi-pathological anatomical models in inverted vat photopolymerization 3D printing

Size matters! Investigating the effects of model size on anatomy learning

Three-dimensional (3D) scanning and printing technology has allowed for the production of anatomical replicas at virtually any size. But what size optimizes the educational potential of 3D printing models? This study systematically investigates the effect of model size on nominal anatomy learning. The study population of 380 undergraduate students, without prior anatomical knowledge, were randomized to learn from two of four bone models (either vertebra and pelvic bone [os coxae], or scapula and sphenoid bone), each model 3D printed at 50%, 100%, 200%, and either 300% or 400% of normal size. Participants were then tested on nominal anatomy recall on the respective bone specimens. Mental rotation ability and working memory were also assessed, and opinions regarding learning with the various models were solicited. The diameter of the rotational bounding sphere for the object ("longest diameter") had a small, but significant effect on test score (F(2,707) = 17.15, p < 0.05, R²  = 0.046). Participants who studied from models with a longest diameter greater than 10 cm scored significantly better than those who used models less than 10 cm, with the exception of the scapula model, on which performance was equivalent across all sizes. These results suggest that models with a longest diameter beyond 10 cm are unlikely to incur a greater size-related benefit in learning nominal anatomy. Qualitative feedback suggests that there also appear to be inherent features of bones besides longest diameter that facilitate learning.

Trueness of 3D printed partial denture frameworks: build orientations and support structure density parameters

PURPOSE

The purpose of the study was to assess the influence of build orientations and density of support structures on the trueness of the 3D printed removable partial denture (RPD) frameworks.

MATERIALS AND METHODS

A maxillary Kennedy class III and mandibular class I casts were 3D scanned and used to design and produce two 3D virtual models of RPD frameworks. Using digital light processing (DLP) 3D printing, 47 RPD frameworks were fabricated at 3 different build orientations (100, 135 and 150-degree angles) and 2 support structure densities. All frameworks were scanned and 3D compared to the original virtual RPD models by metrology software to check 3D deviations quantitatively and qualitatively. The accuracy data were statistically analyzed using one-way ANOVA for build orientation comparison and independent sample t-test for structure density comparison at (α = .05). Points study analysis targeting RPD components and representative color maps were also studied.

RESULTS

The build orientation of 135-degree angle of the maxillary frameworks showed the lowest deviation at the clasp arms of tooth 26 of the 135-degree angle group. The mandibular frameworks with 150-degree angle build orientation showed the least deviation at the rest on tooth 44 and the arm of the I-bar clasp of tooth 45. No significant difference was seen between different support structure densities.

CONCLUSION

Build orientation had an influence on the accuracy of the frameworks, especially at a 135-degree angle of maxillary design and 150-degree of mandibular design. The difference in the support's density structure revealed no considerable effect on the accuracy.

Optimization of Digital Light Processing Three-Dimensional Printing of the Removable Partial Denture Frameworks; The Role of Build Angle and Support Structure Diameter

The optimal three-dimensional (3D) printing parameters of removable partial denture (RPD) frameworks should be studied to achieve the best accuracy, printing time, and least materials consumed. This study aimed to find the best build angle and support structures’ diameter of the 3D printed (RPD) framework. Sixty (RPD) frameworks (10 in each group) were manufactured by digital light processing (DLP) 3D printing technology at three build angles (110-D, 135-D, and 150-D) and two support structures diameters (thick, L, and thin, S). Six groups were named according to their printing setting as (110-DS, 135-DS, 150-DS, 110-DL, 135-DL, and 150-DL). Frameworks were 3D scanned and compared to the original cast surface using 3D metrology software (Geomagic Control X; 3D Systems, Rock Hill, SC). Both printing time and material consumption were also recorded. Data were tested for the significant difference by one-way analysis of variance (ANOVA) test at (α = 0.05). The correlations between outcome parameters were also calculated. The 110-DL group showed the least accuracy. Significantly, the printing time of the 150-D groups had the lowest time. Material consumption of group 110-DS presented the lowest significantly statistical value. Printing time had a linear correlation with both accuracy and material consumption. Within the study limitations, the 150-degree build angle and thin diameter support structures showed optimal accuracy and time-saving regardless of material consumption.