CN102415920A - Manufacturing method of individual stent used for mandibular defect tissue engineering repair - Google Patents

Abstract

The invention relates to a manufacturing method of an individual stent used for mandibular defect tissue engineering repair. After an original model of a mandible is rebuilt through CT (computed tomography) data of a patient, a repair model is designed in a mirror algorithm or curved surface reperforating mode, then a dummy of a defect area is obtained in a cutting algorithm to obtain an individual appearance, and the individual stent made of a biological material is manufactured in an SLS (selective laser sintering) method through BOOL operation between the external shape and the internal microstructure of the stent. The invention provides the manufacturing method of the individual stent used for the mandibular defect tissue engineering repair, which has a good synosteosis effect of an implant and surrounding skeleton and is conductive to long-lasting repair.

Description

Manufacturing method of personalized scaffold for mandibular defect tissue engineering repair

technical field

The invention relates to a manufacturing method of a tissue engineering bracket for mandibular defect repair.

Background technique

Tissue engineering is the application of engineering and life science principles and methods to understand the relationship between the structure and function of mammalian tissues (under normal or pathological conditions), and to develop artificial biomaterials to restore, maintain or improve their functions. As a science and technology for generating functional tissues and organs for transplantation, tissue engineering integrates image measurement technologies such as CT/MRI, 3D reconstruction technology, rapid prototyping technology, material engineering technology, bioengineering technology and other disciplines. The basic principle is that tissue can be separated from the patient, grow and expand in a tissue scaffold made of special materials, and finally form a scaffold-guided three-dimensional tissue. In this way, the resulting three-dimensional tissue can be transplanted into the same patient to replace the function of the diseased tissue.

Tissue regeneration mainly lies in the structural formability of the tissue scaffold and the bioreactor function of the scaffold under the action of seed cells. Scaffolds are composed of structural elements such as pores, fibers, and membranes that are randomly, fractally, or periodically distributed, and can be replicated and manufactured through engineering methods. When a three-dimensional tissue structure is used to develop artificial replacement tissues, the biomaterials in the scaffold structure can be engineered to optimize the structure and meet certain nutritional conditions.

In recent years, maxillofacial defects, especially mandibular defects, have been increasing year by year due to tumors, infections, traffic accidents and other reasons. In Europe alone, 1.5 million people need craniofacial surgery for bone reconstruction each year, of which a considerable number One part is surgery on the mandible. The difficulty in repairing mandibular defects lies in the restoration of the patient's appearance and oral chewing functions, so there are special requirements for the shape and structure of the implant. The current mandibular defect repair surgery mainly adopts autologous bone grafting and metal prosthesis implantation. The operation is very difficult, resulting in insufficient blood supply to the implant, which makes it difficult to control the absorption of the autogenous bone implant, which affects the repair effect. When metal implants are repaired, although the personalized customization technology based on the patient's own bone structure is relatively mature, the design and manufacture of the internal structure of the implant faces many difficulties, which leads to the gap between the metal implant and the surrounding bone after the implantation operation. Poor osseointegration affects the effect of long-term repair.

Aiming at the problems existing in the current repair of mandibular defects, the present invention proposes a personalized bracket that matches the patient's facial structure, which is manufactured through rapid prototyping of biomaterials with good biocompatibility, and after biological culture and implantation surgery , for tissue engineering repair of mandibular defects. On the one hand, the application of the scaffold can better restore the appearance and appearance of the patient; on the other hand, through the degradation of the scaffold and guide the growth of new bone, the bone defect will be completely replaced by the patient's own bone. After the implant restoration is completed, The patient's oral function is fully restored.

Contents of the invention

In order to overcome the inadequacy of the osseointegration effect between the metal implant and the surrounding bone after implantation in the existing mandibular defect repair process, which affects the effect of long-term repair, the present invention provides an osseointegration effect between the implant and the surrounding bone A method for manufacturing a personalized scaffold for mandibular defect tissue engineering repair that is good and beneficial to long-term repair.

The technical solution adopted by the present invention to solve its technical problems is:

A manufacturing method of a personalized bracket for the tissue engineering repair of mandibular defects. After reconstructing the original model of the mandible from the patient's CT data, the repair model is designed by using the mirror algorithm or the method of surface filling holes, and then through the cutting algorithm. The restoration of the defect area is obtained, the personalized shape is obtained, and the design model of the personalized bracket is obtained through the BOOL operation between the external shape of the bracket and the internal microstructure, and finally the personalized bracket is manufactured with biomaterials by the SLS method.

Further, the manufacturing method includes the following steps:

1) CT data acquisition: take CT images of the patient's oral cavity;

2) Three-dimensional model reconstruction of the mandible prototype: use three-dimensional reconstruction software to reconstruct the bone model of the patient's oral cavity, including teeth and mandibular canal;

3) Mandibular repair model design: According to the location of the mandibular defect, two repair options are provided:

(3.1) When there is no cross-central symmetry plane in the defect area, use the mirror image method to symmetry the bone on the healthy side to the affected side, replace the damaged bone, and obtain a complete repair model through the model merging algorithm;

(3.2) When the defect area crosses the central symmetry plane, it is repaired by means of surface patching, that is, according to the curvature change of the surrounding surface of the defect area, the repair surface is designed to make it continuous with the curvature of the surrounding boundary surface;

4) Design the prosthesis to obtain the shape of the personalized bracket: design the osteotomy line in the defect area on the mandible original model, and use the osteotomy line to cut and separate the prosthesis on the repair model. The shape of the prosthesis is the shape of the personalized bracket;

5) Design the internal porous structure of the support: the Cartesian orthogonal truss structure is used as the basic unit of the internal connected hole, first generate the basic unit, and then obtain the operation of the internal connected hole through the array operation in the three coordinate directions of X, Y, and Z respectively frame;

6) Perform Boolean operations on the prosthesis and the internal structure model to obtain a personalized bracket;

7) Utilize the SLS rapid prototyping manufacturing method to manufacture personalized scaffolds using biomaterials.

Furthermore, in the step (3.2), if the size of the hole exceeds the preset value during the hole repairing process, the mirror image model is used as an auxiliary to obtain part of the repairing data.

The technical idea of the present invention is: the personalized scaffold is manufactured by SLS method after the personalized shape and internal microstructure are designed by BOOL operation, and after being cultured in vitro and treated by biological methods, it is surgically implanted in the body for bone reconstruction and repair, and finally A personalized bracket to restore the full function of the patient's oral cavity through dental implants. The personalized shape is prepared by the following methods: (1) reconstruct the original model of the mandible, (2) design the repair model, (3) obtain the restoration of the defect area , the internal microstructure is a regular microstructure designed according to geometric constraints converted from mechanical and biological constraints, and the in vitro culture is carried out by adding growth factors and osteogenic cells into personalized scaffolds, and the geometric constraints are Refers to porosity, pore size.

Specifically, the method described is to reconstruct the original model of the mandible from the patient's CT data, then design the repair model by using the mirror image algorithm or the method of filling holes on the curved surface, and then obtain the restoration of the defect area through the cutting algorithm to obtain a personalized shape , and then through the BOOL operation between the external shape of the scaffold and the internal microstructure, it is manufactured by the SLS method, and after adding growth factors and osteoprogenitor cells for in vitro culture and biological treatment, it is surgically implanted in the body for bone reconstruction and repair, and finally through dental implantation. The implant restores the patient's full function.

The beneficial effect of the present invention is mainly manifested in that the biomaterial with good biocompatibility can be rapidly produced, and after bioculture and implantation, it can be used for tissue engineering repair of mandibular defect. The application of the scaffold can better restore the appearance and appearance of the patient, and through the degradation of the scaffold and guide the growth of new bone, the bone defect will be completely replaced by the patient's own bone. After the implant restoration is completed, the oral function of the patient will be improved. full recovery.

Description of drawings

Figure 1 is a map of the location of the defect area.

Fig. 2 is a design diagram of a restoration model based on the mirror image algorithm, where (a) is the original model, (b) is the mirror image model, (c) is the defective restoration, and (d) is the restoration model.

Fig. 3 is the design drawing of the restoration model using mirror image and filling holes, where (a) is the original model, (b) is the mirror image model, (c) is the defect restoration, (d) is the merged model, and (e) is the supplementary model. hole; (f) is the repair model.

Figure 4 is a diagram of the prosthetic prosthesis.

Figure 5 is a structural diagram of an orthogonal truss.

Fig. 6 is a basic unit diagram of the stent structure.

Fig. 7 is a frame diagram of internal structure operation.

Figure 8 is a diagram of a personalized stent.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Referring to Figure 1, a manufacturing method of a personalized bracket for tissue engineering repair of mandibular defects, after reconstructing the original model of the mandible from the CT data of the patient, the repair model is designed by using the mirror algorithm or the method of filling holes on a curved surface. Then the restoration of the defect area is obtained through the cutting algorithm, and the personalized shape is obtained, and then the design model of the personalized bracket is obtained through the BOOL operation between the external shape of the bracket and the internal microstructure, and finally the personalized bracket is manufactured with biomaterials by the SLS method .

In this embodiment, the manufacturing method is applied to the process of mandibular defect repair, which specifically includes the following steps:

1) CT data acquisition: take CT images of the patient's oral cavity;

2) Three-dimensional model reconstruction of the mandible prototype: use three-dimensional reconstruction software to reconstruct the bone model of the patient's oral cavity, including teeth and mandibular canal;

3) Mandibular repair model design: According to the location of the mandibular defect shown in Figure 1, two repair model design methods are provided.

(3.1) When the defect area is located in areas 1 and 2 shown in Figure 1, since the defect site does not have a cross-central symmetry plane, the bone on the healthy side is symmetrical to the affected side using the mirror image method, and the damaged bone is replaced. Through the model The merging algorithm results in a complete inpainting model. as shown in picture 2.

(3.2) When the defect area is located in the third area shown in Figure 1, since the defect part straddles the central symmetry plane, repairing is carried out by means of surface filling, that is, according to the curvature change of the surrounding surface of the defect area, the repair is designed The surface is made to be curvature continuous with the surrounding boundary surfaces. In the hole patching process, if the hole is large, the mirror model can be used as an auxiliary to obtain part of the patching data to improve the authenticity of the patched surface. As shown in Figure 3.

4) Design the prosthesis to obtain the shape of the personalized bracket: design the osteotomy line in the defect area on the original mandible model, and use the osteotomy line to cut and separate the prosthesis on the repair model. The shape of the prosthetic prosthesis is the shape of the personalized bracket, as shown in FIG. 4 .

5) Design the internal porous structure of the support: the Cartesian orthogonal truss structure shown in Figure 5 is used as the basic unit of the internal communication hole, and the support is changed by adjusting the two parameters of the diameter r of the circular shaft and the center distance t between the two circular shafts in the figure porosity. First generate the basic unit shown in Figure 6, and then obtain the calculation framework of the internal connected holes through array operations in the three coordinate directions of X, Y, and Z, as shown in Figure 7.

6) Perform Boolean operations on the prosthetic prosthesis and the internal structure model to obtain a personalized bracket, as shown in Figure 8.

7) Using the SLS rapid prototyping method, polyvinyl acetate (PCL) was used as the biomaterial to manufacture personalized scaffolds.

8) After being cultured in vitro and implanted in vivo, the scaffold can be used for mandibular defect repair.

Claims (3)

1. manufacturing approach that is used for the personalized support of the engineered reparation of mandibular defect; It is characterized in that: after reconstructing the archetype of mandibular bone through patient CT data; Utilize the mode of mirror image algorithm or curved surface perforations adding to design repairing model; Obtain the dummy of defect area then through cutting algorithm, obtain personalized profile, again through the BOOL computing between support external shape and the internal microstructure; Obtain designing a model of individual character support, produce personalized support through the SLS method with biomaterial at last.

2. the manufacturing approach that is used for the personalized support of the engineered reparation of mandibular defect as claimed in claim 1 is characterized in that: said manufacturing approach may further comprise the steps:

1) CT data acquisition: the CT image of taking position, patient oral cavity;

2) reconstructing three-dimensional model of mandibular bone prototype: utilize the skeleton model at position, three-dimensional reconstruction software rebuild patient oral cavity, reconstruction model comprises tooth, nervus mandibularis pipe;

3) repairing model of mandibular bone design: the regional location according to the mandibular defect place is different, and two kinds of recovery scenarios are provided:

(3.1) do not have span centre heart symmetrical plane when defect area, the skeleton that utilizes mirror method will be good for side is symmetric to Ipsilateral, and replaces damaged skeleton, obtains complete repairing model through the model merge algorithm;

(3.2) striden across Center Symmetry Plane when defect area, utilized the mode of curved surface perforations adding to repair, promptly the curvature according to the defect area peripheral curved surface changes, and design repairs that curved surface makes it and the border curvature of curved surface is continuous on every side;

4) design prosthesis; Obtain the profile of personalized support: section bone line that will on the model of mandibular bone original shape, design defect area; Utilize this section bone line on repairing model, the prosthesis cutting and separating to be come out, the profile of this prosthesis is the profile of personalized support;

5) the inside loose structure of design support: Descartes's quadrature truss structure at first generates elementary cell as the elementary cell in internal communication hole, obtains the computing framework in internal communication hole through the array operation to X, Y, three coordinate directions of Z respectively then;

6) prosthesis and internal structure model are carried out Boolean calculation, obtain personalized support;

7) utilize SLS rapid shaping manufacturing approach, adopt biomaterial to produce personalized support.

3. the manufacturing approach that is used for the personalized support of the engineered reparation of mandibular defect as claimed in claim 2; It is characterized in that: in the said step (3.2); In the perforations adding process,, utilize mirror image model to repair data as the auxiliary part that obtains if hole size exceeds preset value.

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