Method for manufacturing dental prostheses

Abstract

To provide a dental prosthesis capable of improving wearing feeling, and reducing pain and discomfort when wearing the dental prosthesis.SOLUTION: A manufacturing method of a dental prosthesis has the steps of: calculating a pressure distribution 101 to an oral mucosa by the dental prosthesis 100 based on a three-dimensional data set of the dental prosthesis 100 and a three-dimensional data set of the oral mucosa 105; and determining a space area 107 for elastic manufacturing material 109 inside the dental prosthesis based on the calculated pressure distribution.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a dental prosthesis and a manufacturing apparatus for manufacturing a dental prosthesis.

Background Art

[0002] The production of current dentures is a labor-intensive process. In particular, the optimization of the geometric shape of dentures to achieve the best fit often requires numerous consultations.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present invention is to improve the fit of a dental prosthesis and reduce the pain and discomfort during wearing of the dental prosthesis.

Means for Solving the Problems

[0004] The above problems are solved by the subject matter of the independent claims. Technically preferred embodiments are the subject matter of the dependent claims, the detailed description of the invention, and the accompanying drawings.

[0005] According to a first aspect, a method for manufacturing a dental prosthesis includes calculating a pressure distribution on the oral mucosa by the dental prosthesis based on a three-dimensional dataset of the dental prosthesis and a three-dimensional dataset of the oral mucosa; and determining a spatial region for an elastic manufacturing material inside the dental prosthesis based on the calculated pressure distribution. The spatial region forms a secondary volume of the dental prosthesis. According to this method, a technical advantage of improving the fit of the dental prosthesis is achieved. In addition, long-term alveolar ridge resorption of the dental prosthesis can be prevented.

[0006] According to a technically preferred embodiment of this method, the manufacturing material corresponding to a spatial region is determined based on the pressure distribution. The manufacturing material can be selected from a plurality of manufacturing materials. This achieves the technical advantage that, for example, not only the extension of the spatial region but also the manufacturing material can be determined based on the pressure distribution. This further improves the fit of the dental prosthesis.

[0007] According to another technically preferred embodiment of this method, the pressure distribution is calculated using the finite element method. This achieves technical advantages such as the ability to calculate the pressure distribution quickly and with high accuracy.

[0008] According to another technically preferred embodiment of this method, the pressure distribution is calculated when a given stress is present on a dental prosthesis. This achieves the technical advantage of being able to consider the stresses that occur when calculating the pressure distribution and when designing the spatial domain, for example.

[0009] According to another technically preferred embodiment of this method, a given stress is detected by a byte block sensor. This achieves the technical advantage that, for example, the actual stress and engagement point are used in the calculation of the pressure distribution.

[0010] According to another technically preferred embodiment of this method, the pressure distribution on the dental prosthesis is calculated from the pressure distribution on the oral mucosa. This achieves a technical advantage, for example, that allows for precise fitting of spatial areas within the dental prosthesis.

[0011] According to another technically preferred embodiment of this method, the thickness of the spatial region is proportional to the pressure distribution on the dental prosthesis. This achieves the technical advantage that, for example, the spatial region can be calculated in a simple manner.

[0012] According to another technically preferred embodiment of this method, the manufacturing material inside the spatial region has a lower elastic modulus than the manufacturing material outside the spatial region. This achieves a technical advantage, for example, that the fit of the dental prosthesis can be improved.

[0013] According to another technically preferred embodiment of this method, the manufacture of dental prostheses is carried out using a three-dimensional printing method. This achieves the technical advantage of being able to manufacture dental prostheses in a simple manner, for example.

[0014] According to another technically preferred embodiment of this method, the three-dimensional printing method uses free-jet material application. This achieves technical advantages such as further improvement in the manufacture of dental prostheses.

[0015] According to a second embodiment, the technical problem is solved by a manufacturing apparatus for manufacturing a dental prosthesis, which comprises a computing device that calculates the pressure distribution on the oral mucosa by the dental prosthesis based on a three-dimensional dataset of the dental prosthesis and a three-dimensional dataset of the oral mucosa; and a determination device that determines the spatial area for elastic manufacturing material inside the dental prosthesis based on the calculated pressure distribution.

[0016] According to a technically preferred embodiment of this manufacturing apparatus, the computing unit is configured to calculate the pressure distribution using the finite element method. This achieves technical advantages such as the ability to calculate the pressure distribution quickly and accurately.

[0017] According to another technically preferred embodiment of this manufacturing apparatus, the determination device is configured to determine the thickness of the spatial region in proportion to the pressure distribution on the dental prosthesis.

[0018] According to another technically preferred embodiment of this manufacturing apparatus, the manufacturing apparatus is configured to apply a manufacturing material having a lower elastic modulus than that outside the spatial domain to the interior of the spatial domain.

[0019] According to another technically preferred embodiment of this manufacturing apparatus, the manufacturing apparatus includes a 3D printer. Thereby, for example, a technical advantage that a dental prosthesis can be manufactured in a simple manner is achieved.

[0020] Next, embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Brief Explanation of Drawings

[0021] [Figure 1] It is a perspective view showing a dental prosthesis in the oral cavity. [Figure 2] It is an explanatory view showing the pressure distribution on the oral mucosa. [Figure 3] It is a cross-sectional view through the dental prosthesis and the oral mucosa. [Figure 4] It is another cross-sectional view through the dental prosthesis and the oral mucosa. [Figure 5] It is a schematic explanatory view showing a manufacturing apparatus for manufacturing a dental prosthesis. [Figure 6] It is a block diagram showing a method for manufacturing a dental prosthesis.

Modes for Carrying Out the Invention

[0022] FIG. 1 is a perspective view showing a dental prosthesis in the oral cavity. The dental prosthesis 100 is, for example, a partial denture or a complete denture that is at least partially placed on the oral mucosa 105 and contacts the oral mucosa. The shape of the dental prosthesis 100 is defined by a three-dimensional dataset 103 - DR. The dataset can additionally include color data as well as data regarding the manufacturing material of the dental prosthesis 100 to be used. The shape of the patient's oral mucosa 105 is also stored in a three-dimensional dataset 103 - MS. When worn, various stresses F act on the dental prosthesis, for example, the stress during chewing of food.

[0023] Figure 2 shows the pressure distribution on the oral mucosa 105 by the dental prosthesis 100. The pressure distribution 101 is calculated from the three-dimensional dataset 103-DR of the dental prosthesis 100 and the three-dimensional dataset 103-MS of the oral mucosa 105. For that purpose, a finite element method (FEM) can be executed to simulate the pressure distribution 101 of the contact of the dental prosthesis 100 against the oral mucosa 105. In the calculation, the mechanical material properties of both the oral mucosa and the denture are considered. A non-linear material model is used to depict the mechanical properties of the oral mucosa. On the other hand, the material properties of the denture material can be assumed to be linearly elastic. Furthermore, it is necessary to consider the geometric non-linearity with respect to the contact points between the denture and the oral mucosa. By completely depicting the mechanical properties of each material, the pressure distribution can be calculated using the assistance of a contact algorithm based on FEM. On the oral mucosa 105, there are areas where the dental prosthesis 100 acts on the oral mucosa 105 with low pressure and areas where the dental prosthesis 100 acts on the oral mucosa 105 with high pressure.

[0024] In the simulation of the pressure distribution 101, the occlusal surface of the dental prosthesis 100 during the chewing process can be considered. Therefore, different chewing processes can be simulated according to the location and the type of food in order to obtain the pressure distribution 101 of the contact pressure of the dental prosthesis 100 on the oral mucosa 105. To optimize the dental prosthesis 100, the case where the most unfavorable stress (worst-case scenario) occurs can be selected. This leads to the maximum peak contact pressure against the oral mucosa 105.

[0025] The simulated localized peak contact pressure can be minimized by the elasticity of the manufacturing material 109 of the dental prosthesis 100, which has a lower modulus of elasticity than the other manufacturing materials 113 of the dental prosthesis 100. This simulation allows for the optimization of the thickness of the manufacturing material 109 with a low modulus of elasticity to keep the peak contact pressure below the pressure pain limit. The Shore hardness (scale A) of the manufacturing material 109 is, for example, 35 to 60 (ISO7619-1). The tensile strength is, for example, 5.5 to 8.5 N / mm². 2 This corresponds to (ISO37 Type 4).

[0026] The resilient manufacturing material 109 for the spatial region 107 is, for example, an elastomer such as silicone. The manufacturing material 113 for the dental prosthesis 100 is, for example, unfilled or filled methyl methacrylate (MMA), which generally has a hardness (Vickers hardness) in the range of 41.63±2.03 to 34.62±2.1. The bending strength (MPa) is, for example, 86.63±1.0 to 69.15±0.88. The impact strength (KJ / m 2 For example, the values ​​are 6.32±0.50 or 2.44±0.31.

[0027] The manufacturing material 109 for the spatial region 107 is more flexible or elastic than the manufacturing material 113 for the dental prosthesis 100.

[0028] Figure 3 shows a cross-section of the dental prosthesis 100 and the oral mucosa 105. After a given stress is defined on the dental prosthesis 100, an optimization algorithm can be used to suppress the peak contact pressure of the dental prosthesis 100 to below the patient's pressure pain limit. In this case, the three-dimensional dataset 103-DR of the dental prosthesis 100 is used in combination with the three-dimensional dataset 103-MS of the oral mucosa 105. First, the pressure distribution 101 on the oral mucosa 105 is calculated under the given stress.

[0029] In this case, the thickness t(x,y,z) of the spatial region 107 of the elastic manufacturing material 109 is optimized in such a way that the most uniform pressure distribution P(x,y,z) possible acts on the oral mucosa 105. Assuming that an integrated or homogeneous material distribution initially exists in the base of the dental prosthesis 100, the three-dimensional distribution of the elastic manufacturing material 109 is guided onto the oral mucosa 105 by the simulated pressure distribution P(x,y,z). This process can be repeated multiple times, for example, until the peak contact pressure of the pressure distribution 101 falls below a given value.

[0030] The algorithm can be executed on a computer that stores a program for performing this method. Therefore, the computer includes a processor capable of processing instructions for executing the algorithm, and a digital memory storing a three-dimensional dataset 103 of the oral mucosa 105 and the dental prosthesis 100.

[0031] Figure 4 shows another cross-section through the dental prosthesis 100 and the oral mucosa 105. The surface pressure distribution 101 is defined by force vectors per area unit, in which case the force vectors originate from the vertices and, ideally, protrude perpendicularly onto the surface or vertices. The local thickness of the elastic manufacturing material 109 on the base surface of the denture base is calculated by applying a constant transformation coefficient to each force vector.

[0032] This method generates a new interior surface by defining a new vertex for each endpoint of a newly calculated vector. This allows the spatial region 109 to be calculated, the local thickness of which depends on the pressure distribution 111 of the dental prosthesis 100. Force vectors protrude from the vertices on the outer base surface, and together with the outer base surface, the newly generated interior surface forms a subspace of the dental prosthesis. The elastic manufacturing material 109 is placed within the spatial region 107 of the subspace. The shape and position of the spatial region 107 can be integrated into the three-dimensional dataset 103-DR of the dental prosthesis 100.

[0033] To prevent intersection or overlap between the original base volume and the newly generated spatial region 109 for the elastic manufacturing material 109 of the dental prosthesis 100, a Boolean operation is used, thereby subtracting the newly generated spatial region from the volume of the original dental prosthesis 100. Within the print CAM software, the type of material is assigned to each divided spatial region according to its elastic modulus.

[0034] In general, calculations of the spatial region for the resilient manufacturing material 109 can also be performed using other methods. For example, a spatial region 107 having a given thickness may exist at the same time that the numerical value of the pressure distribution 101 exceeds a given value.

[0035] Figure 6 shows a block diagram of the method for manufacturing a dental prosthesis 100. In step S101, the pressure distribution 101 from the dental prosthesis 100 onto the oral mucosa 105 is calculated based on a three-dimensional dataset 103-DS of the dental prosthesis 100 and a three-dimensional dataset 103-MS of the oral mucosa 105. Subsequently, in step S102, the spatial area 107 for the resilient manufacturing material 109 inside the dental prosthesis 100 is determined based on the calculated pressure distribution 101. Then, the dental prosthesis 100 having the resilient manufacturing material 109 is manufactured.

[0036] To arrange various manufacturing materials 109 at various positions in a three-dimensional model, additive manufacturing methods (extrusion, free-jet method, inkjet) that allow for the selective application of various materials can be suitably used, in which case the various materials have different elastic moduli.

[0037] The manufacturing material for the hard and high-strength dental prosthesis 100 can be, for example, methyl methacrylate (MMA), and the elastic manufacturing material 109 can be photocurable medical-grade silicone. By having both hard and soft manufacturing materials in the system, an intermediate elastic modulus can also be achieved by synthesizing both manufacturing materials in a specific ratio.

[0038] This method allows for improved comfort of dental prostheses while considering the individual anatomical requirements of each patient. It minimizes pain or discomfort caused by uneven pressure distribution on the dental prosthesis. It can prevent long-term alveolar ridge resorption. In addition, the use of elastic materials in contact with the oral mucosa allows for better long-term comfort, effectively accommodating anatomical growth of the oral mucosa.

[0039] All features described and illustrated in relation to individual embodiments of the present invention can be applied to the present invention in various combinations, thereby achieving effective advantages simultaneously.

[0040] All method steps can be performed using apparatus suitable for carrying out each method step. All functions performed by the feature in question can be method steps in this method.

[0041] The scope of protection of this invention is defined by the appended claims and is not limited by the features described or illustrated in this description. [Explanation of Symbols]

[0042] 100 Dental prostheses 101 Pressure distribution 103 datasets 105 Oral mucosa 107 Spatial domain 109 Manufacturing materials 111 Pressure distribution 113 Manufacturing materials

Claims

1. A method for manufacturing a dental prosthesis (100), comprising the steps of: (S101) calculating the pressure distribution (101) from the dental prosthesis (100) onto the oral mucosa (105) based on a three-dimensional data set (103-DS) of the dental prosthesis (100) and a three-dimensional data set (103-MS) of the oral mucosa (105); and (S102) determining a spatial region (107) that forms a subspace for elastic manufacturing material (109) inside the dental prosthesis (100) based on the calculated pressure distribution (101); wherein the pressure distribution (111) onto the dental prosthesis (100) is calculated from the pressure distribution (101) onto the oral mucosa (105), and the thickness of the spatial region (107) is proportional to the pressure distribution (111) onto the dental prosthesis (100).

2. The method according to claim 1, wherein the manufacturing material corresponding to a spatial region (107) is determined based on the pressure distribution (101).

3. The method according to claim 1 or 2, wherein the pressure distribution (101) is calculated using the finite element method.

4. The method according to claim 1, wherein the pressure distribution (101) is calculated when a given stress is present on a dental prosthesis (100).

5. The method according to claim 4, wherein a given stress is detected by a bite block sensor.

6. The method according to claim 1, wherein the manufacturing material (109) inside the spatial region (107) has a lower elastic modulus than the manufacturing material (113) outside the spatial region (107).

7. The method according to claim 1, wherein the manufacturing of a dental prosthesis (100) is carried out using a three-dimensional printing method.

8. The method according to claim 7, wherein the three-dimensional printing method uses a free-jet material application method.

9. A manufacturing apparatus (200) for manufacturing a dental prosthesis (100), comprising: a calculation device (201) that calculates the pressure distribution (101) from the dental prosthesis (100) onto the oral mucosa (105) based on a three-dimensional data set (103-DS) of the dental prosthesis (100) and a three-dimensional data set (103-MS) of the oral mucosa (105); and a determination device (203) that determines a spatial region (107) that forms a subspace for elastic manufacturing material (109) inside the dental prosthesis (100) based on the calculated pressure distribution (101), wherein the determination device (203) is configured to determine the thickness of the spatial region (107) in proportion to the pressure distribution (111) onto the dental prosthesis (100).

10. The manufacturing apparatus (200) according to claim 9, wherein the computing device (201) is configured to calculate the pressure distribution (101) using the finite element method.

11. The manufacturing apparatus (200) according to claim 9, wherein the manufacturing apparatus (200) is configured to apply a manufacturing material (109) having a lower elastic modulus than that outside the spatial region (107) to the interior of the spatial region (107).

12. The manufacturing apparatus (200) according to claim 9, wherein the manufacturing apparatus (200) includes a three-dimensional printer.

Images