scholarly journals Adapting the Pore Size of Individual, 3D-Printed CPC Scaffolds in Maxillofacial Surgery

2021 ◽  
Vol 10 (12) ◽  
pp. 2654
Author(s):  
David Muallah ◽  
Philipp Sembdner ◽  
Stefan Holtzhausen ◽  
Heike Meissner ◽  
André Hutsky ◽  
...  

Three dimensional (3D) printing allows additive manufacturing of patient specific scaffolds with varying pore size and geometry. Such porous scaffolds, made of 3D-printable bone-like calcium phosphate cement (CPC), are suitable for bone augmentation due to their benefit for osteogenesis. Their pores allow blood-, bone- and stem cells to migrate, colonize and finally integrate into the adjacent tissue. Furthermore, the pore size affects the scaffold’s stability. Since scaffolds in maxillofacial surgery have to withstand high forces within the jaw, adequate mechanical properties are of high clinical importance. Although many studies have investigated CPC for bone augmentation, the ideal porosity for specific indications has not been defined yet. We investigated 3D printed CPC cubes with increasing pore sizes and different printing orientations regarding cell migration and mechanical properties in comparison to commercially available bone substitutes. Furthermore, by investigating clinical cases, the scaffolds’ designs were adapted to resemble the in vivo conditions as accurately as possible. Our findings suggest that the pore size of CPC scaffolds for bone augmentation in maxillofacial surgery necessarily needs to be adapted to the surgical site. Scaffolds for sites that are not exposed to high forces, such as the sinus floor, should be printed with a pore size of 750 µm to benefit from enhanced cell infiltration. In contrast, for areas exposed to high pressures, such as the lateral mandible, scaffolds should be manufactured with a pore size of 490 µm to guarantee adequate cell migration and in order to withstand the high forces during the chewing process.

2018 ◽  
Vol 1 (1) ◽  
pp. 1243-1248
Author(s):  
Adem Demir ◽  
Mustafa Keser ◽  
Fatih Çalışkan

In recent years, patient-specific solutions and additive manufacturing (AM) have become increasingly important in the treatment of bone defects in studies performed on the medical field. In this direction, additive manufacturing methods use in scaffold fabrication, and many advantages of these systems come to the forefront. Porosity affects the mechanical properties, biocompatibility, and biodegradability of tissue engineering scaffolds. In this study, the effect of different porosity ratios on the mechanical properties of scaffolds for polylactic acid (PLA) and polycaprolactone (PCL) scaffolds was studied. With this fabrication method can be formed entirely 3D interconnected porous scaffolds with pore size. Three different (20%, 35%, and 50%) porosity ratios were determined for both materials, and the mechanical properties of the samples were determined by compression test. The scaffolds fabricated with larger pore size showed lower mechanical performance compared to scaffolds with smaller pore size.


2021 ◽  
pp. 155633162199633
Author(s):  
Mehran Ashouri-Sanjani ◽  
Shima Mohammadi-Moghadam ◽  
Parisa Azimi ◽  
Navid Arjmand

Background: Pedicle screw (PS) placement has been widely used in fusion surgeries on the thoracic spine. Achieving cost-effective yet accurate placements through nonradiation techniques remains challenging. Questions/Purposes: Novel noncovering lock-mechanism bilateral vertebra-specific drill guides for PS placement were designed/fabricated, and their accuracy for both nondeformed and deformed thoracic spines was tested. Methods: One nondeformed and 1 severe scoliosis human thoracic spine underwent computed tomographic (CT) scanning, and 2 identical proportions of each were 3-dimensional (3D) printed. Pedicle-specific optimal (no perforation) drilling trajectories were determined on the CT images based on the entry point/orientation/diameter/length of each PS. Vertebra-specific templates were designed and 3D printed, assuring minimal yet firm contacts with the vertebrae through a noncovering lock mechanism. One model of each patient was drilled using the freehand and one using the template guides (96 pedicle drillings). Postoperative CT scans from the models with the inserted PSs were obtained and superimposed on the preoperative planned models to evaluate deviations of the PSs. Results: All templates fitted their corresponding vertebra during the simulated operations. As compared with the freehand approach, PS placement deviations from their preplanned positions were significantly reduced: for the nonscoliosis model, from 2.4 to 0.9 mm for the entry point, 5.0° to 3.3° for the transverse plane angle, 7.1° to 2.2° for the sagittal plane angle, and 8.5° to 4.1° for the 3D angle, improving the success rate from 71.7% to 93.5%. Conclusions: These guides are valuable, as the accurate PS trajectory could be customized preoperatively to match the patients’ unique anatomy. In vivo studies will be required to validate this approach.


Materials ◽  
2018 ◽  
Vol 11 (2) ◽  
pp. 238 ◽  
Author(s):  
Su Park ◽  
Hyo-Jung Lee ◽  
Keun-Suh Kim ◽  
Sang Lee ◽  
Jung-Tae Lee ◽  
...  

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Matteo Meglioli ◽  
Adrien Naveau ◽  
Guido Maria Macaluso ◽  
Sylvain Catros

Abstract Aim This systematic review aimed to evaluate the use of three-dimensional (3D) printed bone models for training, simulating and/or planning interventions in oral and cranio-maxillofacial surgery. Materials and methods A systematic search was conducted using PubMed® and SCOPUS® databases, up to March 10, 2019, by following the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) protocol. Study selection, quality assessment (modified Critical Appraisal Skills Program tool) and data extraction were performed by two independent reviewers. All original full papers written in English/French/Italian and dealing with the fabrication of 3D printed models of head bone structures, designed from 3D radiological data were included. Multiple parameters and data were investigated, such as author’s purpose, data acquisition systems, printing technologies and materials, accuracy, haptic feedback, variations in treatment time, differences in clinical outcomes, costs, production time and cost-effectiveness. Results Among the 1157 retrieved abstracts, only 69 met the inclusion criteria. 3D printed bone models were mainly used as training or simulation models for tumor removal, or bone reconstruction. Material jetting printers showed best performance but the highest cost. Stereolithographic, laser sintering and binder jetting printers allowed to create accurate models with adequate haptic feedback. The cheap fused deposition modeling printers exhibited satisfactory results for creating training models. Conclusion Patient-specific 3D printed models are known to be useful surgical and educational tools. Faced with the large diversity of software, printing technologies and materials, the clinical team should invest in a 3D printer specifically adapted to the final application.


Author(s):  
Maoen Pan ◽  
Chaoqian Zhao ◽  
Zeya Xu ◽  
Yuanyuan Yang ◽  
Tianhong Teng ◽  
...  

Long-term placement of non-degradable silicone rubber pancreatic duct stents in the body is likely to cause inflammation and injury. Therefore, it is necessary to develop degradable and biocompatible stents to replace silicone rubber tubes as pancreatic duct stents. The purpose of our research was to verify the feasibility and biological safety of extrusion-based 3D printed radiopaque chitosan (CS) ducts for pancreaticojejunostomy. Chitosan-barium sulfate (CS-Ba) ducts with different molecular weights (low-, medium-, and high-molecular weight CS-Ba: LCS-Ba, MCS-Ba, and HCS-Ba, respectively) were soaked in vitro in simulated pancreatic juice (SPJ) (pH 8.0) with or without pancreatin for 16 weeks. Changes in their weight, water absorption rate and mechanical properties were tested regularly. The biocompatibility, degradation and radiopaque performance were verified by in vivo and in vitro experiments. The results showed that CS-Ba ducts prepared by this method had regular compact structures and good molding effects. In addition, the lower the molecular weight of the CS-Ba ducts was, the faster the degradation rate was. Extrusion-based 3D-printed CS-Ba ducts have mechanical properties that match those of soft tissue, good biocompatibility and radioopacity. In vitro studies have also shown that CS-Ba ducts can promote the growth of fibroblasts. These stents have great potential for use in pancreatic duct stent applications in the future.


RSC Advances ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 6724-6732 ◽  
Author(s):  
Ji Li ◽  
Wei Li ◽  
Zhongli Li ◽  
Yuxing Wang ◽  
Ruiling Li ◽  
...  

The fully porous Ti6Al4V cup fabricated by the sintered technique showed high porosity, large pore size with good mechanical properties. It may be effective in achieving in vivo stability after the total hip arthroplasty.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2589 ◽  
Author(s):  
Fei Liu ◽  
Qichun Ran ◽  
Miao Zhao ◽  
Tao Zhang ◽  
David Z. Zhang ◽  
...  

Porous scaffolds with graded open porosity combining a morphology similar to that of bone with mechanical and biological properties are becoming an attractive candidate for bone grafts. In this work, scaffolds with a continuous cell-size gradient were studied from the aspects of pore properties, mechanical properties and bio-functional properties. Using a mathematical method named triply periodic minimal surfaces (TPMS), uniform and graded scaffolds with Gyroid and Diamond units were manufactured by selective laser melting (SLM) with Ti-6Al-4V, followed by micro-computer tomography (CT) reconstruction, mechanical testing and in vitro evaluation. It was found that gradient scaffolds were preferably replicated by SLM with continuous graded changes in surface area and pore size, but their pore size should be designed to be ≥ 450 μm to ensure good interconnectivity. Both the Gyroid and Diamond structures have superior strength compared to cancellous bones, and their elastic modulus is comparable to the bones. In comparison, Gyroid exhibits better performances than Diamond in terms of the elastic modulus, ultimate strength and ductility. In vitro cell culture experiments show that the gradients provide an ideal growth environment for osteoblast growth in which cells survive well and distribute uniformly due to biocompatibility of the Ti-6Al-4V material, interconnectivity and suitable pore size.


Author(s):  
F.S. Senatov ◽  
K.V. Niaza ◽  
M.Yu. Zadorozhnyy ◽  
A.V. Maksimkin ◽  
S.D. Kaloshkin ◽  
...  

2016 ◽  
Vol 10 (4) ◽  
Author(s):  
Erol Cansiz ◽  
Fatih Turan ◽  
Yunus Ziya Arslan

Mandibular sagittal split osteotomy (SSO) is an operation performed for the correction of mandibular deformities. In this operation, sharp rotary tools are used during osteotomies and this can induce some complications. For example, if the inferior alveolar nerve is damaged, paralysis of the teeth, the lateral side of the tongue, and the corner of the lip can occur. To decrease the occurrence of such possible complications, we designed and manufactured a novel computer-assisted, patient-specific SSO guide and soft tissue retractor in our previous study. And, we first tested this apparatus on a cadaveric bone in vitro. Now, in this study, a surgical application of the instrument, which was designed and manufactured according to the requirements of the mandibular sagittal split osteotomies, was performed. This paper gives and discusses the results obtained from in vivo application of the apparatus.


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