CN113636868A

CN113636868A - Surface coating method of zirconia ceramic implant material and application thereof

Info

Publication number: CN113636868A
Application number: CN202110956324.2A
Authority: CN
Inventors: 韩建民; 李楠; 郭传瑸
Original assignee: Peking University School of Stomatology
Current assignee: Peking University School of Stomatology
Priority date: 2021-08-19
Filing date: 2021-08-19
Publication date: 2021-11-12
Anticipated expiration: 2041-08-19
Also published as: CN113636868B

Abstract

The invention relates to the technical field of surface treatment of implant materials, in particular to a surface coating method of a zirconia ceramic implant material and application thereof. The surface coating method of the zirconia ceramic implant material provided by the invention is to form a metal oxide film on the surface of the zirconia ceramic substrate by utilizing an atomic layer deposition technology. According to the invention, the atomic layer deposition technology is applied to the preparation of the functionalized surface of the zirconia ceramic implant material for the first time according to the medical requirements, so that the surface chemical characteristics of the zirconia ceramic implant material that the growth is self-limited under the medium-low temperature condition (500 ℃) are utilized, and the metal oxide is plated on the surface of the zirconia ceramic material layer by layer in the form of a single-atom film, thereby obtaining a metal oxide film with uniform and compact thickness, controllable thickness, adjustable components and nano-scale film thickness, realizing the construction of the functionalized surface of the zirconia implant, and further playing different biological functions.

Description

Surface coating method of zirconia ceramic implant material and application thereof

Technical Field

The invention relates to the technical field of surface treatment of implant materials, in particular to a surface coating method of a zirconia ceramic implant material and application thereof.

Background

Compared with the traditional titanium and titanium alloy implant material, the zirconia ceramic implant material has excellent aesthetic property, better biocompatibility, lower peri-implant inflammation risk, good mechanical property and huge application potential. However, like titanium, zirconium oxide is a biologically inert material, and the surface of zirconium oxide needs to be activated to ensure that the zirconium oxide has good bioactivity and osteogenic property.

At present, the surface activation treatment of the zirconia surface is a surface roughening treatment mode of titanium implant materials, such as sand blasting and acid etching, to improve the surface roughness. However, zirconia ceramics, as a non-metallic material, have a higher degree of difficulty in roughening the surface thereof as compared to a metallic material, and it is difficult to obtain the same roughening result as that of titanium surface treatment, thereby limiting the wide clinical application thereof.

For this reason, the prior art proposes treating the surface of zirconia ceramics by surface coating treatment means, such as electrophoretic deposition, chemical deposition, plasma spraying, spin coating, etc., in order to obtain a bioactive surface. However, these surface coating treatment means have the following problems:

(1) the surface of the zirconia ceramic implant material has a precise thread structure, and the surface coating method is difficult to obtain a uniformly distributed surface coating on the complex structure.

(2) The thickness of the coating obtained by the conventional surface coating method is micron-sized, the coating is relatively too thick, the coating is not tightly combined with a zirconia substrate, the coating is easy to strip, and the coating is difficult to popularize and apply clinically.

To this end, the prior art proposes further improvements. For example, CN112274692A discloses a preparation method of a zirconia implant biological coating, which adopts a sand blasting machine to perform sand blasting roughening treatment on the surface of a pretreated zirconia implant, so as to obtain a zirconia implant with a rough surface; placing the zirconia planting body part with the rough surface in a micron-sized zirconia suspension liquid, soaking for a first preset time, taking out, and then placing in a sintering furnace for sintering to obtain a zirconia planting body with a concave-convex porous structure on the surface; and spraying zirconium dioxide particles to the surface of the zirconium oxide implant with the concave-convex porous structure by adopting a supersonic plasma spraying method to prepare the biological coating with the micro-nano structure. According to the method, the biological activity is realized by changing the microstructure of the coating, but the preparation process of the micro-nano structure is too complicated, and the slurry dipping and sintering method is difficult to obtain a porous structure with uniform distribution, so that the coating is easy to be uneven. In addition, because the biological activity of the coating depends on the material and microstructure of the coating, the material of the coating obtained by the method is still the inert material zirconium dioxide, the overall biological activity is still relatively low, the function of the coating is single, and the clinical application range is small.

CN111411336A discloses an artificial implant, the base of which is selected from zirconia, and a tantalum nanostructure coating with a certain thickness and good bonding force with the zirconia base is formed on the surface of the zirconia by utilizing magnetron sputtering combined with anodic oxidation technology, so that the roughness and the hydrophilicity of the surface of the implant are increased, and the early osseointegration of the zirconia implant is promoted. However, the coating obtained by the method has the thickness of between 500 and 2000nm, and is easy to fall off from the matrix due to the excessive thickness of the coating, so that the clinical application is limited.

Disclosure of Invention

The invention provides a surface coating method of a zirconia ceramic implant material in a first aspect. The coating method provided by the invention can ensure that the coating is tightly combined with the substrate zirconia ceramic material, and solves the problem that the current micron-sized coating is easy to fall off; the material and thickness of the coating can be adjusted according to different clinical requirements, so that the implant material has different functions, such as increasing bioactivity, promoting osteogenesis, increasing adhesive property or wear resistance and the like, and various clinical problems of the zirconia ceramic implant are solved; in addition, the method is relatively simple, easy to control and suitable for large-scale production.

The surface coating method of the zirconia ceramic implant material provided by the invention is characterized in that a metal oxide film is formed on the surface of the zirconia ceramic substrate by utilizing an atomic layer deposition technology.

The invention firstly proposes that the atomic layer deposition technology is applied to the surface treatment of the zirconia ceramic implant material, and metal oxide with bioactivity or osteogenic property is plated on the surface of the zirconia ceramic substrate layer by layer in a monoatomic film mode by utilizing the surface chemical property of self-limited growth under the condition of medium and low temperature (<500 ℃), thereby solving the problems of over-thick coating thickness and uneven coating distribution existing in the existing zirconia ceramic implant material surface coating method; the obtained uniform and compact metal oxide film with nano-scale film thickness can further improve the bioactivity and the osteogenic property of the zirconia ceramic implant material.

The invention further discovers that because the zirconium oxide material has strong inertia and high hardness, when the atomic layer deposition technology is directly applied, a deposition product is in an amorphous structure, is easy to dissolve in vivo, and has difficult exertion of biological effect, even can cause anaphylaxis or toxic reaction. Therefore, the metal oxide film is preferably a functionalized gradient coating with adjustable film layer material and thickness, so as to play different biological effects through the time-sequence release of different element components.

In addition, the wear resistance of the film can be adjusted by regulating and controlling the thickness. The thickness of each film layer of the functionalized gradient coating can be determined according to specific actual needs, for example, the range of 10nm to 70 nm.

Furthermore, the invention adjusts the material and thickness of each film layer in the functional gradient coating by adjusting the type, deposition sequence and cycle number of the precursor.

Furthermore, the invention realizes the timing sequence of different nanometer film components and the exertion of precisely controlled biological effect by tempering the metal oxide film to regulate and control the microstructure (such as crystallinity) of the metal oxide film, solves the problem that the current direct atomic layer deposition technology only focuses on deposition and ignores the biological effect, and obtains the functional preparation technology of the bioactive ceramic with strong practicability, good combination with a substrate and definite biological effect. The microstructure includes a crystalline structure and an amorphous structure.

The metal oxide of the present invention is a metal oxide having a biological activity or an osteogenic property, such as titanium oxide, magnesium oxide, silicon oxide, aluminum oxide, zirconium oxide, and the like. The invention further finds that the microstructure of the formed film layer shows different bioactivity or osteogenic performance for different metal oxides.

For example, certain films having a particular crystalline structure have the advantage of promoting cell adhesion, growth and proliferation compared to amorphous structures. Taking titanium oxide as an example, compared with an amorphous structure, an anatase crystal structure of the titanium oxide has the advantages of high stability of a film in vivo and good biological activity, and can promote the attachment, proliferation and differentiation of osteoblasts. Therefore, the bottom layer of the metal oxide film is a film layer with a crystal structure obtained through tempering treatment.

Preferably, the bottom layer of the metal oxide film is a titanium oxide film layer with an anatase crystal structure obtained through tempering treatment, and the thickness of the titanium oxide film layer is 10-30 nm. The conditions of the tempering treatment are as follows: the temperature is 300 ℃ and 600 ℃, and the time is 5-60 min.

Compared with a crystal structure, the film with a part of amorphous structure has more bioactivity. Taking magnesium oxide as an example, the amorphous structure of the magnesium oxide can better release magnesium ions, thereby playing a better biological function; moreover, the thickness of the film is different, the amount of the released magnesium ions is different, and different biological functions can be exerted, for example, the thickness of the magnesium oxide film is 30-70nm, and the effect of promoting osteogenesis is optimal. Therefore, the surface layer of the metal oxide film is limited to be a film layer with an amorphous structure obtained through tempering treatment.

Preferably, the surface layer of the metal oxide thin film is a magnesium oxide film layer with an amorphous structure obtained by tempering treatment, and the thickness of the magnesium oxide film layer is 30-70 nm.

And preferably, the intermediate layer of the metal oxide film is a silicon oxide film layer with an amorphous structure obtained by tempering treatment, and the thickness of the silicon oxide film layer is 10-30 nm. Through the arrangement of the silicon oxide film layer, the bonding effect of the surface layer and the bottom layer can be improved, and the adhesiveness of the metal oxide film and the substrate is further improved.

Further, the conditions of the tempering treatment of the titanium oxide film layer or the silicon oxide film layer with the amorphous structure are as follows: the temperature is not more than 100 ℃ and the time is not more than 60min, which can be determined according to the type of the metal oxide and the actual requirement.

In a second aspect, the present invention provides an implant material obtained by the above surface coating method.

As one embodiment of the implant material, the implant material comprises a zirconia ceramic substrate and a metal oxide film covered on the surface of the zirconia ceramic substrate;

the metal oxide film is a functionalized gradient coating, and the layer structure is as follows:

a first layer: the thickness of the titanium oxide film layer with the crystal structure is 10-30 nm;

a second layer: the thickness of the magnesium oxide film layer with an amorphous structure is 30-70 nm.

Or, the metal oxide film is a functionalized gradient coating, and the layer structure is as follows:

a second layer: the thickness of the silicon oxide film layer with an amorphous structure is 10-30 nm;

and a third layer: the thickness of the magnesium oxide film layer with an amorphous structure is 30-70 nm.

Researches show that the functionalized gradient coating obtained by the invention has excellent osteogenesis performance, wherein the silicon oxide or titanium oxide film layer has good adhesion performance.

As one embodiment of the present invention, a preparation method for forming a metal oxide thin film on a surface of a zirconia ceramic substrate by ALD technique is provided, the reaction principle of which is shown in fig. 1, and the preparation method comprises the following steps:

(1) introducing a precursor A of tetradimethylamino titanium into a reaction cavity, and carrying out primary surface reaction with a reaction site on a zirconia ceramic substrate;

the operating conditions are as follows: the reaction temperature in the reaction cavity is 100-300 ℃;

(2) purging with inert gas to remove unreacted precursor A and volatile byproduct dimethylamine in the reaction chamber;

(3) introducing the precursor B water into a reaction cavity, carrying out a second surface reaction with the site subjected to the surface reaction in the step (1), and converting the surface back to an initial surface with the same reaction site;

(4) purging with inert gas again to complete a cycle process, and depositing a titanium oxide film for the first time;

(5) repeating the steps (1) to (4) until the thickness of the titanium oxide film reaches the target thickness; the total thickness is not more than 100 nm;

(6) and (5) carrying out heating tempering treatment on the implant material obtained in the step (5) to obtain the titanium oxide film with the anatase crystal structure.

The technical scheme of the invention has the following beneficial effects:

(1) the invention firstly proposes that the atomic layer deposition technology is applied to the surface treatment process of the ceramic dental implant material. The metal oxide is plated on the surface of the zirconia ceramic substrate layer by layer in the form of a monoatomic film, so that the obtained zirconia ceramic implant material after surface treatment has good bioactivity and osteogenic performance, and the coating has the advantages of uniformity, compactness and nano-scale film thickness, can be tightly combined with the zirconia ceramic substrate, and solves the problem of limited clinical application.

(2) According to the method, the atom composition and the thickness of each layer in the metal oxide film are controlled by adjusting the precursor type, the deposition sequence and the cycle number in the atomic layer deposition process, so that the film layers have synergistic effect, and the biological characteristics of the zirconia ceramic implant material are obviously improved.

Moreover, the microstructure (such as crystallinity and the like) of the obtained metal oxide film is adjusted by means of heating and tempering treatment, so that the osteogenic performance of the bioactive agent of the zirconia ceramic implant material can be further improved.

(3) The surface coating method has the advantages of relatively simple process, easy control and suitability for large-scale industrial production.

Drawings

Fig. 1 is a schematic diagram illustrating a reaction principle of forming a titanium oxide thin film on a surface of a zirconia ceramic substrate by ALD according to embodiment 1 of the present invention.

FIG. 2 is a cross-sectional SEM and EDS characterization of zirconia ceramic implant materials obtained by different surface treatment processes;

wherein: a. an untreated zirconia ceramic implant material; b. an ALD treated zirconia ceramic implant material having a titania coating; c. the zirconia ceramic implant material with the titanium oxide coating is treated by ALD and tempered.

FIG. 3 is a cross-sectional SEM and Mapping characterization of zirconia ceramic implant materials obtained by different surface treatment processes;

FIG. 4 is a surface XRD representation of zirconia ceramic implant materials obtained under different tempering conditions; where raw indicates the group that had not been tempered.

FIG. 5 shows the results of cell proliferation of zirconia ceramic implant materials obtained under different surface treatment conditions.

FIG. 6 shows the result of soaking the zirconia ceramic implant material with titanium oxide thin film in the ALD method for 2 weeks.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Example 1

The present embodiment provides a preparation method for forming a metal oxide thin film on a surface of a zirconia ceramic substrate by using ALD technology, the reaction principle of which is shown in fig. 1, and the preparation method comprises the following steps:

(5) repeating the steps (1) to (4) until the thickness of the titanium oxide film reaches the target thickness;

(6) and (5) carrying out heating tempering treatment on the implant material obtained in the step (5) to enable the titanium oxide film on the surface of the implant material to have an anatase crystal structure.

Detecting the implant material obtained in the step (6), wherein the result is as follows:

(1) microstructure:

as shown in FIG. 2, the results of Scanning Electron Microscopy (SEM) and energy spectrum analysis (EDS) prove that the ALD surface coating method of the present invention successfully deposits a nanometer-scale thickness of titanium oxide thin film on the surface of a zirconia ceramic substrate material; and after tempering treatment, the film structure is an anatase crystal structure.

As shown in FIG. 3, the results of Scanning Electron Microscopy (SEM) and surface distribution (Mapping) prove that the thin film obtained by the ALD surface coating method has the characteristics of uniform texture and nanometer-scale thickness, and is tightly combined with the zirconia ceramic substrate; particularly, the film is more tightly combined with the substrate after the tempering treatment.

As shown in FIG. 4, the raw group is an untempered group, and the titanium oxide film thereof has an amorphous structure; after different tempering temperatures and time, the surface titanium oxide film has an anatase crystal structure; combining with Mapping results of fig. 3, it can be proved that the atomic composition of the film after the tempering treatment is still stable and the film is dense and uniform.

(2) And (3) biological activity: as shown in FIG. 5, the cell proliferation effect of the implant material obtained by different tempering conditions is better than that of TiO₂The surface coating method of the invention can be used for ensuring that the zirconia ceramic implant has good bioactivity.

(3) Osteogenic properties: as shown in fig. 6, after soaking in Simulated Body Fluid (SBF) for two weeks, the SEM observed appearance of hydroxyapatite on the surface of the sample, and EDS results confirmed the appearance of apatite deposition, which indicates that the sample has good osteogenic properties.

(4) The adhesive property is as follows: the practical use requirements are met;

(5) wear resistance: and the practical use requirement is met.

Example 2

The embodiment provides a preparation method of a functionalized gradient coating for forming a titanium oxide film layer-magnesium oxide film layer on the surface of a zirconia ceramic substrate by an ALD (atomic layer deposition) technology, which comprises the following steps:

steps (1) to (6) were the same as in example 1;

step (7) introducing corresponding precursors, and repeating the steps (1) to (4) to obtain a magnesium oxide film with the target thickness;

and (8) carrying out heating tempering treatment on the obtained implant material to obtain the magnesium oxide film with an amorphous structure.

The results of testing the obtained implant material for bioactivity, osteogenic properties, adhesive properties and wear resistance were comparable to those of example 1.

Example 3

steps (1) to (6) were the same as in example 1;

step (7) introducing corresponding precursors, and repeating the steps (1) to (4) to obtain a silicon oxide film with the target thickness;

and (8) carrying out heating tempering treatment on the implant material obtained in the step (7) to obtain the silicon oxide film with an amorphous structure.

Step (9) introducing corresponding precursors, and repeating the steps (1) to (4) to obtain a magnesium oxide film with the target thickness;

and (10) carrying out heating tempering treatment on the obtained implant material to obtain the magnesium oxide film with an amorphous structure.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A surface coating method of a zirconia ceramic implant material is characterized in that a metal oxide film is formed on the surface of a zirconia ceramic substrate by utilizing an atomic layer deposition technology.

2. The method for coating the surface of the zirconia ceramic implant material according to claim 1, wherein the metal oxide thin film is a functionalized gradient coating with adjustable material and thickness of each film layer.

3. The method for coating the surface of the zirconia ceramic implant material according to claim 2, wherein the material and thickness of each film layer in the functionalized gradient coating are adjusted by adjusting the type, deposition sequence and cycle number of the precursor.

4. The method for surface coating of a zirconia ceramic implant material according to any of claims 1 to 3, wherein the microstructure of the metal oxide film is controlled by tempering the film; the microstructure includes a crystalline structure and an amorphous structure.

5. The method for surface coating of a zirconia ceramic implant material according to claim 4, wherein the bottom layer of the metal oxide thin film has a crystal structure;

preferably, the bottom layer of the metal oxide thin film has a titanium oxide film layer with an anatase crystal structure, and the thickness of the titanium oxide film layer is 10-30 nm.

6. The method for surface coating of a zirconia ceramic implant material according to claim 4 or 5, wherein the surface layer of the metal oxide thin film has an amorphous structure;

preferably, the surface layer of the metal oxide thin film is a magnesium oxide film layer having an amorphous structure and a thickness of 30 to 70 nm.

7. The surface coating method of a zirconia ceramic implant material according to claim 6, wherein the intermediate layer of the metal oxide thin film is a silica film layer of an amorphous structure with a thickness of 10 to 30 nm.

8. An implant material obtainable by the surface coating method according to any one of claims 1 to 7.

9. The implant material of claim 8, comprising a zirconia ceramic substrate and a metal oxide film covering the surface thereof;

10. Implant material according to claim 9, characterized in that the layer structure of the functionalized gradient coating is as follows: