CN105662621B - A kind of porous dental implant and its manufacturing method of drug-carrying slow-released system - Google Patents

Abstract

A kind of porous dental implant of drug-carrying slow-released system, outer surface including planting body ontology described in planting body ontology is equipped with the external screw thread being connect with alveolar bone, it is in porous structure between the externally threaded adjacent thread, the hole for placing slow releasing pharmaceutical is equipped in the porous structure.And a kind of manufacturing method of the porous dental implant of drug-carrying slow-released system.The present invention provide it is a kind of effectively improve bond strength, promoted in conjunction with speed, be easily achieved porous structure drug-carrying slow-released system porous dental implant and its manufacturing method.

Description

A porous dental implant capable of carrying a sustained drug release system and its manufacturing method

technical field

The invention relates to the field of porous dental implants, in particular to a porous dental implant and a manufacturing method thereof.

Background technique

In recent years, the application of dental implant technology has aroused people's high attention. The implanted teeth can not only solve the confusion of traditional denture restoration, but also get rid of the inconvenience caused by movable dentures. close to natural teeth. The success of implant surgery and the good function of restoration depend on many factors, and the combination effect of implant and alveolar bone is one of the key factors. In order to promote the integration of implants and alveolar bone, dental implants with rough surfaces have been widely used. Animal experiments and clinical practice have shown that compared with smooth surfaces, rough surfaces can increase the osseointegration surface area and are beneficial to implants. Combination with alveolar bone. However, the bonding strength between the implant and the alveolar bone with a rough surface is far from the ideal clinical effect. How to further increase the bonding strength between the implant and the alveolar bone, improve the long-term effectiveness of the implant, and improve the success of implant surgery rate is a problem to be solved.

As one of the medical materials implanted in the body, titanium's surface structure is an important factor affecting the quality of the implant, and largely determines whether the implant can be combined with the bone for a long time and perform its function. The existence of microporous structure on the surface of titanium implant can increase the surface area of the implant, improve the mechanical locking force, and facilitate the combination of the implant and bone tissue. The design of porous implants needs to meet the following requirements:

(1) The designed porous implant can not only meet the personalized external shape, but also can build controllable internal pores;

(2) The designed porous structure needs to meet the requirements of biological and mechanical properties. It needs to have sufficient rigidity and strength to ensure that it will not be deformed and damaged after being implanted in the alveolar bone. At the same time, its elastic modulus must be the same as that of natural bone. The elastic modulus is basically the same, avoiding stress shielding;

(3) The designed porous structure needs to meet the process requirements of additive manufacturing technology;

(4) The structural performance parameters of the porous structure should be controllable.

Existing implants are all completed by traditional machining, and then the final shape and structure are obtained through surface post-processing. For the porous structure of the implant surface, it is difficult to achieve it only by using traditional processing methods.

The existing dental implants have poor bonding strength with the alveolar bone, and a long bone growth and healing period of 3-6 months is required between implant placement and repair surgery.

Contents of the invention

In order to overcome the shortcomings of existing dental implants such as poor bonding strength, poor rapidity, and difficulty in realizing a porous structure, the present invention provides a portable drug buffer that can effectively improve the bonding strength, increase the bonding speed, and easily realize a porous structure. A porous dental implant with a release system and a method of making the same.

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

A porous dental implant capable of carrying a sustained-release drug system, comprising an implant body. The outer surface of the implant body is provided with external threads connected to the alveolar bone, and the adjacent threads of the external threads have a porous structure. , the porous structure is provided with pores for placing slow-release medicines.

Further, in the porous structure, each pore is distributed in a helical manner as a whole.

Furthermore, the pores are arranged at equal intervals.

Still further, on the outer surface of the implant body, the porosity is 30-70%.

The diameter of the pores is between 300-800 microns

The sustained release drug is bone morphogenic protein.

A method for manufacturing a porous dental implant capable of carrying a sustained-release drug system, the method comprising the steps of:

1) Design threaded implants in 3D software;

2) In the 3D software, on the basis of the implant in step 1), establish a porous model. The parameters include: cross-sectional shape of the hole, pore diameter, pore depth, porosity and distribution of the pores. After the design is completed, output the STL format. document;

3) Using SLM technology, use titanium alloy powder as the raw material to 3D print out the implant designed in step 2), and then remove the residual powder inside the pores of the implant;

4) The ultrasonically oscillated implant is subjected to sandblasting and acid etching to remove residual unmelted inorganic matter on the surface.

Further, in said step 3), the process of 3D printing is as follows:

According to the layered slice information of the 3D CAD model of the molded part, the scanning system controls the laser beam to act on the powder in the area to be molded;

After a layer is scanned, the piston in the piston cylinder will drop a distance of layer thickness; then the powder feeding system will convey the powder, and the rollers of the powder spreading system will spread a layer of thick powder and deposit it on the formed layer;

Then, repeat the above two forming processes until all the sliced layers of the 3D CAD model are scanned. In this way, the 3D CAD model is directly formed by layer-by-layer accumulation.

Furthermore, after the sintering of the porous dental implant is completed, the implant is placed in the powder pile in the vacuum chamber and slowly cooled to room temperature to remove excess powder sticking to the dental implant.

Furthermore, the residual powder inside the implant pores was removed by ultrasonic vibration with 70% ethanol.

The technical idea of the present invention is: with the development of metal additive manufacturing technology, porous structures and porous implants with greater design freedom can be directly manufactured, including some fine and tiny geometric features, so the porous structure When designing, it is not limited to the limitations of traditional design and manufacturing methods and concepts, and more consideration can be given to the bionic structure and mechanical properties to design a more free structure. Selective laser melting (SLM) technology has attracted much attention because it can manufacture medical metal parts with specific precise geometric shapes or complex internal pores through layer-by-layer accumulation of metal powder.

The side structure of the implant body is conducive to the storage and release of drugs and the porous structure of bone ingrowth. Drugs can promote the differentiation and growth of bone cells in the body fluid environment, and bone cells can also grow into the porous structure, so that the implant and alveolar bone are firmly established. In order to shorten the healing period of surgery, promote osseointegration, increase the strength of osseointegration, improve the long-term effectiveness of dental implants, and improve the success rate of implant surgery.

The beneficial effects of the present invention are mainly manifested in that the bonding strength is effectively improved, the bonding speed is increased, and the porous structure is easily realized.

Description of drawings

Figure 1 is a schematic diagram of a porous dental implant that can carry a sustained drug release system.

Detailed ways

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

Referring to Fig. 1, a porous dental implant capable of carrying a drug slow-release system includes an implant body 1 and a porous structure 2; the outer surface of the body is provided with an external thread 3 connected to the alveolar bone, and the porous structure is embedded between the threads , in the porous structure 2, each pore is helically distributed as a whole, and the pores are conducive to drug storage and release and bone ingrowth; the pores of the porous structure 2 exist independently, there is no connected structure between the pores, and the pore size is between 300- Between 800 microns, the porosity is 30-70% controllable.

A method for manufacturing a porous dental implant capable of carrying a drug slow-release system, the steps of which are as follows:

1) Design a threaded implant based on certain parameters in 3D software such as Unigraphix, Pro/E, and Solidworks.

2) In Unigraphix, Pro/E, Solidworks and other three-dimensional software, on the basis of the implant in step 1, a porous model is established. The parameters include: the cross-sectional shape of the hole, the diameter of the hole, the depth of the hole, the porosity and the distribution of the holes, After the design is completed, output the file in STL format.

3) Using SLM technology, use titanium alloy powder as raw material to 3D print the implant designed in step 2, and then use 70% ethanol to ultrasonically vibrate to remove the residual powder inside the pores of the implant.

4) The ultrasonically oscillated implant is subjected to sandblasting and acid etching to remove residual unmelted inorganic matter on the surface.

The selective laser melting (Selective Laser Melting, SLM) technology in the above step 3) is a new rapid prototyping (RP) technology that appeared in the mid-1990s. It has the advantages of simple molding process, high material utilization rate, wide applicability and high molding efficiency, so it has received extensive attention. It can directly form metal parts that are close to full density. According to the layered slice information of the 3D CAD model of the molded part, the scanning system (galvanometer) controls the laser beam to act on the powder in the area to be molded. After a layer is scanned, the piston in the piston cylinder will drop a distance of a layer thickness; then the powder feeding system will deliver a certain amount of powder, and the rollers of the powder spreading system will spread a layer of thick powder and deposit it on the formed layer. Then, repeat the above two molding processes until all the slice layers of all 3D CAD models are scanned. In this way, the 3D CAD model directly forms the metal part through layer-by-layer accumulation. After the sintering of the porous dental implant is completed, the implant is placed in the powder pile in the vacuum chamber and slowly cooled to room temperature, and the excess powder sticking to the dental implant is removed.

The basic process parameters of the SLM technology are as follows: the thickness of the processing layer is 30 μm, the scanning speed is 7 m/s, the laser power is 200 W, the point spacing is 75 μm, and the oxygen content in vacuum is below 1000 ppm.

The powder material is titanium alloy or cobalt chromium alloy.

The porous dental implant of the present embodiment, which can carry a drug slow-release system, has the following characteristics:

The main body threaded implant is a parametrically designed implant, and the specifications and thread parameters of the implant are controllable;

Based on the porous structure of the implant body, the cross-sectional shape of the hole is not unique, and can be circular, square, rhombus and other geometric shapes;

In order to meet the requirements of SLM processing technology for the forming of porous structure, the diameter of the hole is required to be more than 300 microns, and the parameterization is controllable;

The porosity of the porous structure is the ratio of the sum of the cross-sectional areas of all pores to the surface area of the implant. Since all pores are of the same size, the porosity can be changed by changing the number or distribution of the pores, and finally the porosity can be controlled;

Bone morphogenic proteins (BMPs) are members of the transforming growth factor superfamily, among which BMP-2 has the strongest and fastest osteoinductive ability. However, clinically, if BMP-2 is directly applied locally, it will be quickly dispersed and absorbed, and its effect of inducing osteogenesis is very limited. In order to obtain the maximum osteoinductive ability of BMP-2, it is necessary to find an ideal carrier. An ideal carrier material not only has good biocompatibility, can load drugs into bone defects in various forms such as adsorption, binding, and mosaic, but also has certain mechanical strength and degradation speed. Commonly used carriers include collagen, sodium hyaluronate (SA), antelope-based apatite (HA), demineralized bone matrix (DBM), calcium phosphate (TCP), and polylactic acid P (LA).

After the post-manufacturing treatment of the implant is completed, the porous structure is used as a carrier platform for BMP2 particles to build a sustained drug release system. Further, by controlling a series of parameters such as cross-sectional shape, pore diameter, pore depth, porosity and pore distribution of the porous structure, the release rate, release amount and release cycle of BMP2 can be controlled.

The porous dental implant of the present invention includes an implant body 1 and a porous structure 2, and an external thread 3 is provided on the outer surface of the implant body, and the external thread 3 is connected with the alveolar bone. The porous structure 2 is embedded between the threads, and the pores are also helically distributed, the pore size is between 300-800 microns, and the porosity is controllable at 30-70%. Its microstructure can be referred to in Figure 2; the external thread 3 The connection with the alveolar bone is a common mechanical connection, which is used to fix the implant and the alveolar bone at the initial stage of implantation. After implantation, the medicine inside the porous structure 4 begins to release slowly in the body fluid environment, promoting bone cell regeneration. Rapid growth can also provide bone cell growth space, thereby forming a chimeric structure between the porous structure 4 and the alveolar bone, so that the biological fixation of the dental implant and the alveolar bone can be obtained, and an ideal clinical osseointegration effect can be achieved.

Example: Figure 1 is a schematic diagram of the two-dimensional structure of a porous dental implant that can carry a drug sustained release system. The neck diameter is the same. In the middle part of the implant, a porous structure is established at the thread intervals. The implant size is 3.75*10mm, the neck diameter is 3.75mm, and the length is 10mm. The cross-sectional area of a single hole in the porous structure is rhombus, its diagonal length is 0.5 mm, and its depth is also 0.5 mm. The holes are evenly distributed at equal intervals in the axial direction, and are helically distributed in the circumferential direction, and a hole is established every 60°.

Claims (6)

1. A porous dental implant capable of carrying a drug slow-release system, comprising an implant body, characterized in that: the outer surface of the implant body is provided with an external thread connected to the alveolar bone, and the corresponding external thread There is a porous structure between the adjacent threads, and there are pores for placing slow-release drugs in the porous structure; in the porous structure, each pore is distributed in a helical manner as a whole; each pore is arranged at equal intervals; in the implant body The outer surface of the implant has a porosity of 30-70%; the diameter of the pores is between 300-800 microns; the implant body is a structure of revolution, and there is a screw thread between the neck and the root, and the outer diameter of the screw thread is the same as The diameter of the implant neck is the same; in the middle part of the implant, a porous structure is established at the thread interval. The model of the implant body is 3.75*10mm, the diameter of the neck is 3.75mm, and the length is 10mm; The diagonal length is 0.5mm, and the depth is also 0.5mm; the holes are evenly spaced in the axial direction and helically distributed in the circumferential direction, and a hole is established every 60°. 2. The porous dental implant capable of carrying a sustained drug release system as claimed in claim 1, wherein the sustained release drug is bone morphogenic protein. 3. A method for manufacturing a porous dental implant capable of carrying a sustained drug release system as claimed in claim 1, wherein the method for manufacturing comprises the steps of: 1) Design threaded implants in 3D software; 2) In the 3D software, on the basis of the implant in step 1), establish a porous model. The parameters include: cross-sectional shape of the hole, pore diameter, pore depth, porosity and distribution of the pores. After the design is completed, output the STL format. document; 3) Using SLM technology, use titanium alloy powder as the raw material to 3D print out the implant designed in step 2), and then remove the residual powder inside the pores of the implant; The process parameters of the SLM technology are as follows: the processing layer thickness is 30 μm, the scanning speed is 7 m/s, the laser power is 200 W, the point spacing is 75 μm, and the oxygen content in vacuum is below 1000 ppm; 4) The ultrasonically oscillated implant is subjected to sandblasting and acid etching to remove residual unmelted inorganic matter on the surface. 4. The manufacturing method according to claim 3, characterized in that: in the step 3), the process of 3D printing is as follows: According to the layered slice information of the 3D CAD model of the molded part, the scanning system controls the laser beam to act on the powder in the area to be molded; After a layer is scanned, the piston in the piston cylinder will drop a distance of layer thickness; then the powder feeding system will convey the powder, and the rollers of the powder spreading system will spread a layer of thick powder and deposit it on the formed layer; Then, repeat the above two forming processes until all the sliced layers of the 3D CAD model are scanned. In this way, the 3D CAD model is directly formed by layer-by-layer accumulation. 5. The manufacturing method according to claim 4, characterized in that: after the sintering of the porous dental implant is completed, the implant is placed in a powder pile in a vacuum chamber and slowly cooled to room temperature to remove the sticky dental implant. excess powder. 6. The manufacturing method according to claim 4 or 5, characterized in that: the residual powder inside the pores of the implant is removed by ultrasonic vibration with a mass fraction of 70% ethanol.