With the rapid progression of additive manufacturing and the emergence of new 3D printing technologies, accuracy assessment is mostly being performed on isosymmetric test bodies. However, the ...accuracy of anatomic models can vary. The dimensional accuracy of root mean square values in terms of trueness and precision of 50 mandible replicas, printed with five common printing technologies, were evaluated. The highest trueness was found for the selective laser sintering printer (0.11 ± 0.016 mm), followed by a binder jetting printer (0.14 ± 0.02 mm), and a fused filament fabrication printer (0.16 ± 0.009 mm). However, highest precision was identified for the fused filament fabrication printer (0.05 ± 0.005 mm) whereas other printers had marginally lower values. Despite the statistically significance (
< 0.001), these differences can be considered clinically insignificant. These findings demonstrate that all 3D printing technologies create models with satisfactory dimensional accuracy for surgical use. Since satisfactory results in terms of accuracy can be reached with most technologies, the choice should be more strongly based on the printing materials, the intended use, and the overall budget. The simplest printing technology (fused filament fabrication) always scored high and thus is a reliable choice for most purposes.
Comparisons of the material qualities of pressed, milled, and 3D-printed occlusal devices are sparse, complicating informed decisions on material choice.
The purpose of this in vitro study was to ...compare the material properties of pressed, milled, and 3D-printed resins, as well as how these are affected by thermal aging. These data were then used to estimate the likely clinical performance of the tested materials.
Three pressed (ProBase Cold; Ivoclar Vivadent AG, Palapress clear; Kulzer GmbH, Aesthetic Blue clear; Candulor), 3 milled (Temp Premium Flexible Transpa; Zirkonzahn, idodentine PMMA transparent; Unión Dental S.A., Yamahachi PMMA clear; Yamahachi Dental MFG), and three 3D-printed (Freeprint splint; DETAX GmbH, LuxaPrint Ortho Plus; DMG GmbH, Nextdent Ortho Clear; Vertex-Dental B.V.) resin materials were evaluated. Flexural strength, Martens hardness (HM), Vickers hardness (HV), water sorption, water solubility, and surface topography were analyzed. The tests were carried out after 50 hours of water storage at 37 °C (baseline) and after simulated aging (50 hours of water storage at 37 °C, followed by 20 000 thermocycles TC at 5 °C and 55 °C).
At baseline, the mean flexural strength values were 92.8 to 99.5 MPa for pressed, 95.1 to 122.0 MPa for milled, and 19.5 to 91.3 MPa for 3D-printed materials. After aging, these values were 87.6 to 93.5 MPa for pressed, 93.1 to 116.0 MPa for milled, and 13.0 to 63.3 MPa for 3D-printed resins. The mean HM values were 130.1 to 134.1 N/mm for pressed and 130.3 to 158.5 N/mm for milled resins. After aging, the mean HM ranged from 121.6 to 124.2 N/mm for pressed and 116.2 to 149.7 N/mm for milled resins. The mean HV values were 18.2 to 19.9 for pressed and 18.4 to 23.0 for milled resins before aging and 16.9 to 18.7 for pressed and 17.3 to 22.3 N/mm for milled resins after aging. Printed resins could not be measured. At baseline, the mean modulus of elasticity ranged from 4.6 to 4.8 GPa for pressed and from 4.7 to 5.3 GPa for milled resins. For 3D-printed resins, only 1 material could be measured (3.7 GPa). The mean sorption values were 8.6 to 9.2 μg/mm3 for pressed, 7.9 to 10.5 μg/mm3 for milled, and 9.2 to 21.2 μg/mm3 for additive resins. After aging, these values were 21.1 to 22.6 μg/mm3 for pressed, 20.5 to 23.7 μg/mm3 for milled, and 19.4 to 45.5 μg/mm3 for 3D-printed resins. The mean solubility values ranged from 0.3 to 1.4 μg/mm3 for pressed, 0.4 to 1.7 μg/mm3 for milled, and −3.5 to 11 μg/mm3 for 3D-printed materials.
Pressed and milled resins can be considered equivalent in terms of their material properties. Relative to the pressed and milled resins, the 3D-printed resins had lower flexural strength and hardness values and higher water sorption and solubility.
Additive manufacturing (AM) is rapidly gaining acceptance in the healthcare sector. Three-dimensional (3D) virtual surgical planning, fabrication of anatomical models, and patient-specific implants ...(PSI) are well-established processes in the surgical fields. Polyetheretherketone (PEEK) has been used, mainly in the reconstructive surgeries as a reliable alternative to other alloplastic materials for the fabrication of PSI. Recently, it has become possible to fabricate PEEK PSI with Fused Filament Fabrication (FFF) technology. 3D printing of PEEK using FFF allows construction of almost any complex design geometry, which cannot be manufactured using other technologies. In this study, we fabricated various PEEK PSI by FFF 3D printer in an effort to check the feasibility of manufacturing PEEK with 3D printing. Based on these preliminary results, PEEK can be successfully used as an appropriate biomaterial to reconstruct the surgical defects in a “biomimetic” design.
Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today's craniomaxillofacial surgeons use patient information ...for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.
Orbital cavernous hemangiomas are the most common primary orbital tumors in adults, providing challenges for optimal surgical approach planning within an anatomically complex area with close ...proximity to vital neurovascular structures. The authors present an individualized lateral mini-orbitozygomatic approach for the resection of an orbital cavernous haemangioma based on a preoperative 3-dimensional-printed model. This individualized approach enabled the surgeons to achieve optimal exposure while maintaining safety during the resection of the lesion, but also to respect the patient's physiognomy and hairline. In addition, the model was used for patient informed consent, helping the patient understand the procedure. Although adding additional effort to preoperative planning, 3-dimensional model-based approaches can offer great benefits when it comes to customizing surgical approaches, especially for anatomically challenging resections.
The objective of this study was to determine the effect of two plasma surface treatments on the biologic responses of PEEK medical implants manufactured by fused filament fabrication (FFF) 3D ...printing technology.
This study created standard PEEK samples using an FFF 3D printer. After fabrication, half of the samples were polished to simulate a smooth PEEK surface. Then, argon (Ar) or oxygen (O2) plasma was used to modify the bioactivity of FFF 3D printed and polished PEEK samples. Scanning electron microscopy (SEM) and a profilometer were used to determine the microstructure and roughness of the sample surfaces. The wettability of the sample surface was assessed using a drop shape analyzer (DSA) after plasma treatment and at various time points following storage in a closed environment. Cell adhesion, metabolic activity, proliferation, and osteogenic differentiation of SAOS-2 osteoblasts were evaluated to determine the in vitro osteogenic activity.
SEM analysis revealed that several spherical nanoscale particles and humps appeared on sample surfaces following plasma treatment. The wettability measurement demonstrated that plasma surface treatment significantly increased the surface hydrophilicity of PEEK samples, with only a slight aging effect found after 21 days. Cell adhesion, spreading, proliferation, and differentiation of SAOS-2 osteoblasts were also up-regulated after plasma treatment. Additionally, PEEK samples treated with O2 plasma demonstrated a higher degree of bioactivation than those treated with Ar.
Plasma-modified PEEK based on FFF 3D printing technology was a feasible and prospective bone grafting material for bone/dental implants.
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•This study applied plasma surface treatment on FFF 3D printed PEEK samples.•Observed slight aging suggests chairside plasma treatments.•Plasma surface treatment could tailor the bioactivity of PEEK material.•O2 plasma-treated PEEK samples indicated better bioactivation than Ar plasma.•Plasma modified PEEK based on the FFF technology is a promising medical implant.
To compare the suitability of a fused filament fabrication (FFF) consumer 3D printer with a professional digital light processing (DLP) printer for the production of surgical templates for guided ...oral implant surgery.
Eight virtual templates were printed with two different 3D printers. These were optically scanned and the incongruences between virtual and printed templates were determined after alignment of the surface scans and the virtual data. Minimum, maximum, and mean incongruences were determined, and a t test between both groups was performed to determine statistically significant differences in accuracy.
Templates printed with the professional DLP printer showed statistically significantly less incongruence (P = .001) than those fabricated by the consumer FFF 3D printer.
The accuracy of manufactured templates is strongly dependent on the printing device and method. At this time, the tested consumer 3D FFF printer is not suitable for the fabrication of templates for implant guided surgery. Minimum requirements regarding printers' features and 3D-printed templates need to be assessed in future studies.
Occlusal devices can be either conventionally processed, milled, or printed. However, little is known about the biocompatibility of 3D printing resin materials.
The purpose of this in vitro study was ...to compare the viability and morphology of human gingival fibroblast cells (HFG-1) after cultivation on conventionally processed, milled, and printed occlusal device materials with different surface treatments.
Disks of a conventionally processed (PalaXpress Clear pP), milled (Yamahachi PMMA Clear sY), and 2 different printed materials (Dental LT Clear Resin aD; Freeprint splint aF) were prepared. The surfaces of the specimens were finished by using 2 different treatments (unpolished and polished with P1200-grit silicon carbide paper). HGF-1 cells were cultivated on the specimens for 24 hours, and a viability assay was performed by using polystyrene disks as a control (n=9 disks per group). Cell morphology and the topography of the specimens were examined with scanning electron microscopy (n=3 disks per group). Two-way analysis of variance was applied to determine the effect of material and surface treatment followed by the post hoc Fisher least significant difference test (α=.05).
Overall, material (P<.001) and surface treatment (P<.001) significantly influenced the viability of HGF-1 cells. The viability of cells on all specimens displayed mean values between 0.85 and 1.01 compared with the control except for unpolished aD (0.00 ±0.07) and aF (0.02 ±0.05) that had only a few cells with a round shape.
The behavior of HGF-1 cells on conventionally processed and milled specimens was similar and not dependent on the surface treatment. Unpolished printed specimens had a cytotoxic effect. However, after polishing, cell behavior was similar to that of the conventionally processed and milled specimens.
Fused Filament Fabrication (FFF) as an additive manufacturing (AM) method for polyetheretherketone (PEEK) has established a promising future for medical applications so far, however interlayer ...delamination as a failure mechanism for FFF implants has raised critical concerns. A one-dimensional (1D) heat transfer model (HTM) was developed to compute the layer and interlayer temperatures by considering the nature of 3D printing for FFF PEEK builds. The HTM was then coupled with a non-isothermal healing model to predict the interlayer strength through the thickness of a FFF PEEK part. We then conducted a parametric study of the primary temperature effects of the FFF system, including the print bed, nozzle, and chamber temperatures, on layer healing. The heat transfer component of the model for the FFF PEEK layer healing assessment was validated separately. An idealized PEEK cube design (10 × 10 × 10 mm³) was used for model development and 3D printed in commercially available industrial and medical FFF machines. During the printing and cooling processes of FFF, thermal videos were recorded in both printers using a calibrated infrared camera. Thermal images were then processed to obtain time-dependent layer temperature profiles of FFF PEEK prints. Both the theoretical model and experiments confirmed that the upper layers in reference to the print bed exhibited higher temperatures, thus higher healing degrees than the lower layers. Increasing the print bed temperature increased the healing of the layers allowing more layers to heal to 100%. The nozzle temperature showed the most significant effect on the layer healing, and under certain nozzle temperatures, none of the layers healed adequately. Although environment temperature had less impact on the lower layers closer to the print bed, the number of 100% healed layers increased when the chamber temperature increased. The model predictions were in good agreement with the experimental data, particularly for the mid-part of FFF PEEK cubes printed in both FFF machines.11FFF: Fused Filament Fabrication; AM: Additive Manufacturing; PEEK: Polyetheretherketone; 1D: One-dimensional; HTM: Heat transfer model.
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•Print bed temperature plays a critical role in layer healing for FFF PEEK parts.•Interlayer strength increases linearly from the bottom to the top of FFF PEEK builds.•Layer healing in FFF PEEK builds can be enhanced via key FFF temperatures.
Additive manufacturing (AM) of high temperature polymers, specifically polyaryletherketones (PAEK), is gaining significant attention for medical implant applications. As 3D printing systems evolve ...toward point of care manufacturing, research on this topic continues to expand. Specific regulatory guidance is being developed for the safe management of 3D printing systems in a hospital environment. PAEK implants can benefit from many advantages of AM such as design freedom, material and antibacterial drug incorporation, and enhanced bioactivity provided by cancellous bone-like porous designs. In addition to AM PAEK bioactivity, the biomechanical strength of 3D printed implants is crucial to their performance and thus widely studied. In this review, we discuss the printing conditions that have been investigated so far for additively manufactured PAEK implant applications. The effect of processing parameters on the biomechanical strength of implants is summarized, and the bioactivity of PAEKs, along with material and drug incorporation, is also covered in detail. Finally, the therapeutic areas in which 3D printed PAEK implants are investigated and utilized are reviewed.