Dimensional Printing Technique Research Articles

Hyper-anti-freezing bionic functional surface to -90°C.

Freezing phenomenon has troubled people for centuries, and efforts have been made to lower the liquid freezing temperature, raise the surface temperature, or mechanical deicing. Inspired by the elytra of beetle, we demonstrate a novel functional surface for directional penetration of liquid to reduce icing. The bionic functional surface is fabricated by projection microstereolithography (PµSL) based three dimensional printing technique with the wettability on its two sides tailored by TiO2 nanoparticle sizing agent. A water droplet penetrates from the hydrophobic side to the superhydrophilic side of such a bionic functional surface within 20 ms, but it is blocked in the opposite direction. Most significantly, the penetration time of a water droplet through such a bionic functional surface is much shorter than the freezing time on it, even though the temperature is as low as -90°C. This work opens a gate for the development of functional devices for liquid collection, condensation, especially for hyperantifogging/freezing.

Application and advantages of three dimensional printing technique in anteversion evaluation of total hip arthroplasty in patients with lumbar degenerative disease

In recent years, the application of three-dimensional printing (3DP) in the field of medicine has been expanding and has become the focus of clinical research and application. The 3D reconstruction and 1:1 model can be used to analyze and evaluate the prosthesis installation before operation and improve the accuracy and clinical effect of total hip replacement. In particular, the preoperative evaluation of total hip arthroplasty (THA) in patients with spinal-pelvic sagittal plane deformity is significant. Lumbar degeneration is one of the most common spinal-pelvic sagittal plane malformations, it is difficult to determine acetabular anteversion in THA for these patients, and it is easy to cause postoperative complications. At present, 3DP has been used to determine the anteversion of THA in patients with lumbar degenerative disease, and this article reviews the research and application of 3DP in anteversion evaluation of THA for lumbar degenerative disease, as well as its clinical advantages and challenges.

Three Dimensional Printing Technique and Its Application to Bone Tumor Surgery

Three Dimensional Printing Technique and Its Application to Bone Tumor Surgery

Fabrication of Isoniazid/Rifampicin/Poly L-lactic Acid Donut-shaped Implants via Three Dimensional Printing Technique.

Objective To investigate the possibility of manufacturing dual-drug loaded isoniazid/rifampicin/poly L-lactic acid (PLLA) implant with donut-shaped structure via three-dimensional (3D) printing technique and study the drug release characteristic and biocompatibility of the implant in vitro.Methods PLLA was crushed into particles with diameters around 75-100 μm.Isoniazid and rifampicin bulk drugs were dissolved into the organic dissolvent respectively to be the binding liquid.The 3D printing machine fabricated the donut-shaped implant via binding the PLLA powder layer by layer.Dynamic socking method was used to study the in vitro release characteristics,and cell culture experiment was used to test the cytocompatibility of the implant.Results PLLA slow-release implants were made by using the PLLA powder as matrix and isoniazid/rifampicin organic solvent as binding liquid through 3D printing.The drugs in the implants distributed in nest under electron microscope.The concentrations of both drugs were still higher than the lowest effective bacteriostasis concentration after release for 32 days.Cytotoxicity and direct contact tests indicated that the implants had rare cytotoxicity and favorable biocompatibility. Conclusion The donut-shaped implants can be successfully fabricated using the 3D printing method,which offers a new method for the manufacturing of topical slow-release anti-tuberculosis drugs.

The Use of Three Dimensional Printed Hydroxyapatite Granules in Alveolar Ridge Preservation

In this study, an alveolar ridge preservation using novel hydroxyapatite granules which was fabricated by three dimensional printing technique in post-extraction socket was carried out and evaluated. Clinical, radiographic and histology were assessed prior to dental implant placement. Five volunteered patients who needed an extraction of anterior tooth and scheduled for implant replacement were enrolled in this pilot study. No sign of infection or local of systemic immune reaction to the three dimensional printed hydroxyapatite granules in all patients was noted. At 8 weeks post-surgery, the grafted area was observed to be completely filled with woven bone and the formation of new vessels was seen. In addition, the bone quality and quantity of the grafted site when placing the implant showed efficient implant stability (ISQ values ∼ 65) without the need of additional bone graft surgery. Overall results indicated that three dimensional printed hydroxyapatite granules could be potentially employed as bone grafting material for alveolar ridge preservation.

Preparation of simulate craniocerebral models via three dimensional printing technique

Three dimensional (3D) printing technique was used to prepare the simulate craniocerebral models, which were applied to preoperative planning and surgical simulation. The image data was collected from PACS system. Image data of skull bone, brain tissue and tumors, cerebral arteries and aneurysms, and functional regions and relative neural tracts of the brain were extracted from thin slice scan (slice thickness 0.5 mm) of computed tomography (CT), magnetic resonance imaging (MRI, slice thickness 1mm), computed tomography angiography (CTA), and functional magnetic resonance imaging (fMRI) data, respectively. MIMICS software was applied to reconstruct colored virtual models by identifying and differentiating tissues according to their gray scales. Then the colored virtual models were submitted to 3D printer which produced life-sized craniocerebral models for surgical planning and surgical simulation. 3D printing craniocerebral models allowed neurosurgeons to perform complex procedures in specific clinical cases though detailed surgical planning. It offered great convenience for evaluating the size of spatial fissure of sellar region before surgery, which helped to optimize surgical approach planning. These 3D models also provided detailed information about the location of aneurysms and their parent arteries, which helped surgeons to choose appropriate aneurismal clips, as well as perform surgical simulation. The models further gave clear indications of depth and extent of tumors and their relationship to eloquent cortical areas and adjacent neural tracts, which were able to avoid surgical damaging of important neural structures. As a novel and promising technique, the application of 3D printing craniocerebral models could improve the surgical planning by converting virtual visualization into real life-sized models.It also contributes to functional anatomy study.

Use of 3D Printing Model for the Management of Fibrous Dysplasia: Preliminary Case Study

Fibrous dysplasia is a relatively rare disease but the management would be quite challenging. Because this is not a malignant tumor, the preservation of the facial contour and the various functions seems to be important in treatment planning. Until now the facial bone reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for facial bone reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile, various types of allogenic and alloplastic materials have been also used. However, facial bone reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original maxillary anatomy as possible using the 3D printing model, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we molded Titanium mesh to reconstruct three-dimensional maxillary structure during the operation. This prefabricated Titanium-mesh implant was then inserted onto the defected maxilla and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be successful in this patient. Individualized approach for each patient could be an ideal way to restore the facial bone.

3D Printed Titanium Implant for the Skull Reconstruction: A Preliminary Case Study

The skull defect can be made after the trauma, oncologic problems or neurosurgery. The skull reconstruction has been the challenging issue in craniofacial fields for a long time. So far the skull reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for skull reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile various types of allogenic and alloplastic materials have been also used. However, skull reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original skull anatomy as possible using the 3D printed titanium implant, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we fabricated Titanium implant to reconstruct three-dimensional orbital structure in advance, using the 3D printer. This prefabricated Titanium-implant was then inserted onto the defected skull and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.

Experimental study of PLLA/INH slow release implant fabricated by three dimensional printing technique and drug release characteristics in vitro.

BackgroundLocal slow release implant provided long term and stable drug release in the lesion. The objective of this study was to fabricate biodegradable slow release INH/PLLA tablet via 3 dimensional printing technique (3DP) and to compare the drug release characteristics of three different structured tablets in vitro.MethodsThree different drug delivery systems (columnar-shaped tablet (CST), doughnut-shaped tablet (DST) and multilayer doughnut-shaped tablet (MDST)) were manufactured by the three dimensional printing machine and isoniazid was loaded into the implant. Dynamic soaking method was used to study the drug release characteristics of the three implants. MTT cytotoxicity test and direct contact test were utilized to study the biocompatibility of the implant. The microstructures of the implants’ surfaces were observed with electron microscope.ResultsThe PLLA powder in the tablet could be excellently combined through 3DP without disintegration. Electron microscope observations showed that INH distributed evenly on the surface of the tablet in a “nest-shaped” way, while the surface of the barrier layer in the multilayer doughnut shaped tablet was compact and did not contain INH. The concentration of INH in all of the three tablets were still higher than the effective bacteriostasis concentration (Isoniazid: 0.025 ~ 0.05 μg/ml) after 30 day’s release in vitro. All of the tablets showed initial burst release of the INH in the early period. Drug concentration of MDST became stable and had little fluctuation starting from the 6th day of the release. Drug concentration of DST and CST decreased gradually and the rate of decrease in concentration was faster in DST than CST. MTT cytotoxicity test and direct contact test indicated that the INH-PLLA tablet had low cytotoxicity and favorable biocompatibility.ConclusionsThree dimensional printing technique was a reliable technique to fabricate complicated implants. Drug release pattern in MDST was the most stable among the three implants. It was an ideal drug delivery system for the antibiotics. Biocompatibility tests demonstrated that the INH-PLLA implant did not have cytotoxicity. The multilayer donut-shaped tablet provided a new constant slow release method after an initial burst for the topical application of the antibiotic.

Effect of binder content on the material properties of polymethyl methacrylate fabricated by three dimensional printing technique

This study reports the development of polymethyl methacrylate-based mixture which is suitable for direct freeform fabrication by three dimensional printing (3DP) technique. The influence of different compositions on formability, physical and mechanical properties of fabricated 3DP samples was studied. It was found that binder content in the composition should be greater than 10% for successful fabrication of polymethyl methacrylate samples by 3DP technique. This is reported to increase the bulk density by 25%, modulus and strength up to about 40 times and 22 times, respectively and decrease amount of porosity in the specimens by 26% when the binder content increased from 10 to 60%. Dimensional errors of the fabricated parts compared to input graphical image for all formulations did not exceed 6% in all directions.