WO2013187588A1

WO2013187588A1 - Method for treating bonding surfaces of dental restorations, and dental restorations

Info

Publication number: WO2013187588A1
Application number: PCT/KR2013/002734
Authority: WO
Inventors: 이창택; 김보성; 김경훈
Original assignee: Lee Chang-Tack
Priority date: 2012-06-11
Filing date: 2013-04-02
Publication date: 2013-12-19
Also published as: KR101354177B1; KR20130138578A

Abstract

The present invention relates to a method for treating the bonding surfaces of dental restorations and to dental restorations. According to one aspect of the present invention, disclosed is a method for treating the bonding surfaces of dental restorations in which the bonding surface of a zirconia core on which a ceramic layer is to be placed is etched by a solution comprising a mixture of nitric acid (HNO₃) and hydrofluoric acid (HF) so as to improve bonding strength when manufacturing the dental restoration consisting of the zirconia core in the lower portion and the ceramic layer in the upper portion.

Description

METHOD FOR TREATING ADHESIVE SURFACE OF DENTAL RESTORATION AND DENTAL RESTORATION

The present invention relates to a method for treating an adhesive surface of a dental restoration and a dental restorative material, which improves the durability of the dental restoration by enhancing the adhesion between the zirconia core and the porcelain layer in the manufacture of the dental restoration comprising the lower zirconia core and the upper porcelain layer A method of treating an adhesive surface of a tooth restoration, and a tooth restoration.

Dental fillings or castings used to regenerate areas of a tooth damaged by tooth decay are called tooth restoration. Such dental restorations include crown, resin filling, and inlay / onlay.

In recent years, users' expectation for aesthetic aspects of dental restorations has been rising due to the improvement of living standards. For example, in the case of dental restorations covering the whole tooth like crown, restoration of dental restorations using all- Demand is increasing.

In view of mechanical strength such as strength and durability, the use of dental restorative materials using zirconia has been increasing as ceramic materials.

Therefore, it is more preferable to use a dental restoration manufactured by forming a porcelain layer in a coating form on a lower zirconia core rather than preparing a dental restoration with a single material of zirconia.

As a method for forming a ceramic material on a zirconia core, there is a lamination method in which ceramic material is used to form a ceramic material on a zirconia, and a thermal press method in which a ceramic material is manufactured and buried in a similar manner to a metal material. In the lamination method, the porcelain is put into a slurry state by water and then applied to the core by using a brush.

The zirconia core is used to determine the shape of a tooth through a typical dental restoration processing method, for example, 3D modeling (3D optical impression using a 3D optical camera), and a zirconia block that is commercialized and sold is subjected to CAD / CAM Machined, and then sintered.

A final dental restoration is produced through a firing process in a state in which a ceramic layer is formed on a zirconia core.

Fig. 1 shows an example of a sectional structure of a conventional dental restoration. Fig. 1 shows a state in which a zirconia core A is adhered on an abutment C and a porcelain layer B is laminated thereon.

1, the zirconia core A is formed to have a thickness of approximately 0.8 mm and the porcelain layer B to have a thickness of approximately 0.6 to 1.2 mm in consideration of an aesthetic aspect, The relatively small ceramics (400 MPa) is formed to a thickness not smaller than the thickness of zirconia (900 to 1200 MPa), which is not good in terms of mechanical properties such as strength and durability.

In view of this, it is preferable that the ceramic layer is laminated so that the thickness of the ceramic layer is as small as possible. However, in this case, the adhesion strength (or interface bonding strength) of the ceramic layer to the surface of the zirconia core is insufficient, There are technical limitations that can be made.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks of the prior art to improve the durability of a dental restoration by enhancing the adhesion between a zirconia core and a porcelain layer in the manufacture of a dental restoration comprising a lower zirconia core and an upper porcelain layer And to provide a method for treating an adhesive surface of a tooth restoration and a tooth restoration.

According to an aspect of the present invention, there is provided a method of manufacturing a dental restoration comprising a lower zirconia core and an upper porcelain layer, wherein the bonding surface of the zirconia core on which the porcelain layer is to be formed is nitric acid (HNO ₃ ) A method of treating an adhesive surface of a dental restoration, characterized in that the adhesive strength is improved by etching with a mixed solution of hydrofluoric acid (HF).

More preferably, the mixed solution of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) may be a mixture of 20 to 90% of nitric acid and 10 to 80% of hydrofluoric acid.

More preferably, the mixed solution of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) may be a mixture of 50 to 70% nitric acid aqueous solution and 30 to 55% aqueous hydrofluoric acid solution.

More preferably, the etching can be performed by immersing the bonding surface of the zirconia core in a mixed solution of the nitric acid (HNO ₃ ) and hydrofluoric acid (HF) at room temperature for 1.5 to 2.5 hours.

According to another aspect of the present invention, there is disclosed a dental restoration in which a porcelain layer is formed on an upper surface of an adhesive faced zirconia core by an adhesive surface treatment method of the dental restoration.

More preferably, the zirconia core has a thickness of 0.5 to 1.2 mm, and the upper porcelain layer may have a thickness of 0.1 to 0.5 mm.

More preferably, the upper porcelain layer may be laminated to the adhesive surface of the etched zirconia core using a lamination method.

The present invention enhances the adhesion between a zirconia core and a porcelain layer in the manufacture of a dental restoration comprising a lower zirconia core and an upper porcelain layer to prevent detachment or abrasion of the restoration of the dental restoration, There is an advantage to improve.

In addition, it is possible to increase the thickness of zirconia having good mechanical properties while maintaining the thickness of the ceramic material to a minimum thickness necessary for providing esthetics, thereby providing a dental restoration that improves both aesthetics and mechanical properties.

Further, in terms of the etching process, a relatively short etching time is required to provide a good effect in terms of process efficiency, and a good etching effect can be obtained even at room temperature, thereby providing good effects in terms of work safety.

1 shows an example of a cross-sectional structure of a conventional tooth restoration,

FIG. 2 is a flow chart of a dental restoration manufacturing process to which an adhesive surface treatment method of a dental restoration according to an embodiment of the present invention is applied;

3 is an example of a cross-sectional structure of a dental restoration manufactured by an embodiment of the present invention.

The present invention may be embodied in many other forms without departing from its spirit or essential characteristics. Accordingly, the embodiments of the present invention are to be considered in all respects as merely illustrative and not restrictive.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises", "having", "having", and the like are intended to specify the presence of stated features, integers, steps, operations, components, Steps, operations, elements, components, or combinations of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and a duplicate description thereof will be omitted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a flowchart of a dental restoration manufacturing process to which an adhesive surface treatment method of a dental restoration according to an embodiment of the present invention is applied.

The tooth shape is determined through 3D modeling (3D optical impression taking using a 3D optical camera) (S100).

It is preferable to form a size that is slightly smaller than the external dimensions of the teeth finally required in consideration of the thickness of the porcelain layer that is formed on the upper portion of the teeth when determining the tooth shape of the zirconia core. For example, it is preferable to form the tooth smaller than the external dimension of the required tooth by about 0.1 to 0.5 mm.

Then, the zirconia (ZrO ₂ ) block is machined by the CAD / CAM method according to the teeth shape (S200), and the formed zirconia core is sintered (S300).

Zirconia blocks generally use commercially available products for the manufacture of artificial teeth called CAD / CAM blocks. Such CAD / CAM blocks are manufactured by powder press molding of a bioactive zirconia called '3Y-TZP' do. 3Y-TZP is Partially Stabilized Zirconia (PSZ) using 3mol% Y ₂ O ₃ and is widely used in many fields of industry, especially dental field because of its good properties such as high strength, heat stability and high corrosion resistance . As an example of a commercial CAD / CAM block, there is "ZirBlank (trade name)" of ACUCERA, Inc. of Korea, and the present invention is applicable to a general commercial CAD / CAM block manufactured using 3Y-TZP. As a general commercial CAD / CAM block, for example, those manufactured by D-MAX Corporation, HASS Corporation, SB Company, etc. of Korea may be used.

For the sintering treatment, general sintering conditions of a zirconia prosthesis may be applied, for example, sintering at 1600 DEG C for at least 12 hours.

Then, the bonding surface of the zirconia core is etched (S400). The etching process is performed under the following conditions.

The bonding surface of the zirconia core on which the porcelain layer is to be formed is etched with a mixed solution of nitric acid (HNO ₃ ) and hydrofluoric acid (HF).

The inventors of the present invention have experimentally confirmed that when the nitric acid or hydrofluoric acid is used singly, the etching rate is very slow and the modifying effect of the surface of the zirconia core is less than that when the mixed use is performed. The adhesion surface of the zirconia core is nitric acid ₃ ) and hydrofluoric acid (HF), a good surface modification effect can be obtained, and good results can be obtained in terms of etching time.

Particularly, the mixed solution of the nitric acid (HNO ₃ ) and the hydrofluoric acid (HF) is preferably a mixture of 20 to 90% of nitric acid and 10 to 80% of hydrofluoric acid, more preferably 45 to 55% 45 to 55%.

This is because if the hydrofluoric acid is lower than 10%, the etching proceeds very slowly and the process time is increased. If the hydrofluoric acid is higher than 80%, the strength of the surface of the zirconia core is lowered due to excessive etching. The ratio of the mixed solution of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) means the ratio (volume ratio) of each acid except water in the aqueous solution state.

In consideration of the aqueous solution state, it is preferable to use a mixture of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) mixed with 50 to 70% nitric acid aqueous solution and 30 to 55% aqueous hydrofluoric acid solution.

Both nitric acid (HNO ₃ ) and hydrofluoric acid (HF) have limit values that can be dissolved in water in aqueous solution. The upper limit of the aqueous solution concentration of the aqueous nitric acid solution and the aqueous hydrofluoric acid solution is based on this point, since about 70% of the nitric acid is the maximum and the hydrofluoric acid is the maximum soluble range of about 55%. The mixed solution of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) is mixed with a 50 to 70% nitric acid aqueous solution and a 30 to 55% aqueous solution of hydrofluoric acid because the etching rate is slowed when the aqueous solution concentration of the aqueous nitric acid solution or hydrofluoric acid aqueous solution is lower than the lower limit value. % Hydrofluoric acid aqueous solution is preferably used.

The etching is preferably performed so that the bonding surface of the zirconia core is immersed in the mixed solution of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) at room temperature for 1.5 to 2.5 hours. If the etching time is shorter than 1.5 hours, the etching of the surface of the zirconia core may be insufficient, and if the etching time is longer than 2.5 hours, the etching may be excessive and the bonding strength between the zirconia core and the ceramic layer may be lowered.

In the case of using a mixed solution of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) in terms of the etching temperature, it was confirmed that a good etching effect was obtained even at room temperature. Conventional conventional chemical etching of zirconia has been performed by using calcium sulfate or boiling phosphate at a high temperature of 400 ° C or higher. Such a high-temperature etching involves a risk of high temperature, however, in the case of this embodiment, It is possible to obtain a good etching effect, thereby providing a good effect in terms of work safety.

Then, a ceramic layer is formed on the zirconia core to form a dental restoration (S500), and the dental restoration is subjected to a firing treatment (S600). Preferably, the upper porcelain layer is laminated to the bonded surface of the etched zirconia core using a lamination method. In the laminating method, the porcelain powder is put into a slurry state in water and then applied to a zirconia core using a brush. Although a lamination method is disclosed as a preferred example in this embodiment, various known methods for forming a ceramic material are not excluded.

For the firing treatment, general firing conditions of the porcelain layer may be applied. For example, the temperature may be raised to 50 ° C per minute and then fired at 850 ° C for 1 minute.

Through the above process, finally, a dental restoration comprising the lower zirconia core and the upper porcelain layer is produced.

3 shows an example of a sectional structure of a dental restoration manufactured according to an embodiment of the present invention, showing a state in which a zirconia core A is adhered on an abutment C and a porcelain layer B is laminated thereon have.

When the above-mentioned bonding surface treatment method is used, good bonding strength can be obtained even if the porcelain layer is made thinner than conventional ones. Preferably, the zirconia core has a thickness of 0.5 to 1.2 mm, and the upper porcelain layer may have a thickness of 0.1 to 0.5 mm.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples.

[Example 1]

A large number of zirconia cores were prepared. The zirconia core was prepared by cutting a commercial CAD / CAM block into a suitable size (10 * 10 * 5 mm) for the experiment, and used "ZirBlank (trade name)" of ACUCERA CO., LTD.

The prepared zirconia core was sintered at 1600 占 폚 for 12 hours.

Then, a 70% nitric acid aqueous solution and a 48% hydrofluoric acid aqueous solution were mixed to prepare a mixed solution of 50% nitric acid and 50% hydrofluoric acid at room temperature (25 ° C).

The zirconia core was immersed in the mixed solution and etched for 0.5 to 3.5 hours at intervals of 0.5 hour.

The ceramics layer was formed on each zirconia core that had been etched by using the laminating method, and firing was performed to prepare a specimen. The firing conditions were such that the temperature was raised to 50 ° C per minute and then moored at 850 ° C for 1 minute.

The upper porcelain layer was laminated to a thickness of 80 to 100 탆 and grinded to a thickness of 40 to 50 탆 for an adhesion test.

The adhesion between the zirconia core and the ceramic material layer was measured using a scratch tester. The pressing force was 50 N, and the results are shown in Table 1 below.

Table 1

Etching time (immersion time)	Adhesion (MPa)
0	30.2
0.5	31.3
One	32.5
1.5	35.7
2	36.3
2.5	36.1
3	32.1
3.5	29.3

Referring to Table 1, when the etching time (immersion time) was 1.5 to 2.5 hours, the adhesion was measured to be 35 MPa or more, and compared with the case where no etching was performed (when the etching time was 0) 20%. &Lt; / RTI >

[Example 2]

The prepared zirconia core was sintered at 1600 占 폚 for 12 hours.

Then, one side of the zirconia core was mirror-finished to form a surface to be etched, and then the substrate was immersed in a mixed solution of nitric acid / hydrofluoric acid at room temperature (25 ° C) having various mixing ratios for 2.5 hours to perform etching, And observed with an optical microscope.

As a result of the observation, when the hydrofluoric acid content was less than 10%, no substantial etching effect was observed on the surface to be etched. When the surface to be etched was scratched with a scratch test tip (diamond tip) The strength of the surface was lowered and the tip was torn out.

Referring to these results, it is preferable to use a mixture of nitric acid (HNO ₃ ) and hydrofluoric acid (HF) so that the concentration of nitric acid is 20 to 90% and that of hydrofluoric acid is 10 to 80%.

Although the present invention has been described with reference to the preferred embodiments thereof with reference to the accompanying drawings, it will be apparent to those skilled in the art that many other obvious modifications can be made therein without departing from the scope of the invention. Accordingly, the scope of the present invention should be interpreted by the appended claims to cover many such variations.

Claims

In the manufacture of a dental restoration comprising a lower zirconia core and an upper porcelain layer,

Wherein the bonding surface of the zirconia core to be formed with the porcelain layer is etched with a mixed solution of nitric acid (HNO 3 ) and hydrofluoric acid (HF) to improve the bonding strength.
The method according to claim 1,

Wherein the mixed solution of nitric acid (HNO 3 ) and hydrofluoric acid (HF) is mixed so that 20 to 90% of nitric acid and 10 to 80% of hydrofluoric acid are mixed.
3. The method of claim 2,

Wherein the mixed solution of nitric acid (HNO 3 ) and hydrofluoric acid (HF) is a mixture of 50 to 70% nitric acid aqueous solution and 30 to 55% hydrofluoric acid aqueous solution.
3. The method of claim 2,

Wherein the etching is performed by immersing the bonding surface of the zirconia core in a mixed solution of the nitric acid (HNO 3 ) and hydrofluoric acid (HF) at normal temperature for 1.5 to 2.5 hours.
6. A dental restoration comprising a ceramic layer laminated on top of an adhesive faced zirconia core according to any one of claims 1 to 5.
6. The method of claim 5,

Wherein the zirconia core has a thickness of 0.5 to 1.2 mm and the upper porcelain layer has a thickness of 0.1 to 0.5 mm.
6. The method of claim 5,

Wherein the upper porcelain layer is laminated on the adhesive surface of the etched zirconia core using a lamination method.