JP2004000331A - Method for forming dental prosthesis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which, when making a dental prosthesis in a CAD/CAM scheme for example, a model obtained from a damaged part of a tooth in order to obtain a form of the prosthesis is easily obtained and at least a main part of the model is accurately obtained as data. <P>SOLUTION: This method includes the steps of: forming a local filling part just for a part of a pier tooth which is obtained in the damaged part of the tooth in order to accurately obtain margin line data of the pier tooth; arbitrarily preparing a margin trimming part by molding a heaped up filling material; parameterizing the size of the prosthesis; and the like. The form of the entire dental prosthesis is grasped from main part data and the parameter and based upon the form, a block for the prosthesis is machined. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to a method of forming a dental model mainly manufactured for manufacturing a dental prosthesis and a method of manufacturing a dental prosthesis.
[0002]
[Prior art]
Conventionally, a dental model produced for manufacturing a dental prosthesis is manufactured by the following steps.
(A) A dentist performs an operation of forming an abutment after treating a decayed tooth. The obtained abutment tooth is shown in FIG. 11 is a margin line portion, and 10 is an abutment tooth surface. 12 is a gingival part. From this abutment tooth shape, an abutment tooth model 14M as shown in FIG. 1 (2) is obtained. 10M is a portion where the abutment tooth surface is copied, 11M is a portion where the margin line is copied, and 13M is a margin trimming portion.
(B) Then, take an impression of all teeth, opposing teeth or partial impressions.
Gypsum is poured on the obtained impression material and hardened.
(C) The gypsum model is handed over to a technician to create a divided working model. There is a margin trimming work in the work contents. This operation is very difficult for dentists and requires skill.
(D) Reproduce the original tooth by WAX, change to metal, resin, ceramic, etc. and set it on the patient.
On the other hand, while the contact probe 15 is relatively moved in the X, Y, and Z directions with respect to the obtained abutment tooth model 14M, the surface shape is converted into data based on the contact at the tip thereof, and the data is acquired. A dental prosthesis is also obtained by performing processing such as grinding a prosthesis block based on the surface shape that has been converted and the surface shape of a denture model that is separately obtained.
The margin line 11 is a contact contour where the prosthesis and the abutment come into contact with each other. If the contact is not dense, the portion may cause a secondary stroke. Although it is very important, as described above, the operation is complicated, special techniques are required, and much time is required for forming.
[0003]
[Means to solve the problem]
The present invention does not perform margin trimming by a method such as processing a plaster model as described above, but after taking an impression, coating around the impression margin, and trimming on the impression, so that the method is more accurate and simplified. It is possible to detect the margin line by the technique.
[0004]
One of the features of the present invention is that
A method of forming a dental prosthesis production model by arranging a hardening member locally on a margin line portion of an abutment tooth and then arranging a hardening member around the abutment tooth to form an abutment tooth model It is to propose.
An abutment tooth in the present invention is formed by an operator such as a dentist or a dental technician by shaving a tooth defect part, and a margin line in this case is mainly formed by gingiva and an abutment tooth. It shows the boundary line part, but if it is provided below the gingiva, or if the denture is mounted more upward, the boundary part can be a margin line due to the aesthetics of mounting the denture There is also.
As the curable member in the present invention, a material conventionally used for obtaining an impression (for example, GC Examix Fine (trademark)) is used, and the curing time may be appropriately adjusted according to the working time and the like.
The term “local” refers to a portion that covers at least the margin line and allows the margin line to be copied, and is appropriately determined within the range.
The periphery of the abutment tooth is an extent that covers the abutment tooth and indicates a range within which the surface shape of the abutment tooth can be captured, and is appropriately determined according to the purpose, situation, and the like.
In this manner, by taking a local impression near the margin line, the curable member is sufficiently filled in the margin line, so that an impression having an accurate margin line can be obtained.
[0005]
Another feature of the present invention is to form a primary mold based on a peripheral shape including an abutment tooth and an adjacent tooth, and form around a margin line of the primary mold frame to form a secondary mold. It is to provide a method of creating a model for obtaining abutment data by using the method.
The primary formwork is mainly one that is formed by hardening a hardening member filled around an abutment tooth and then separating the hardening member. However, the primary shaping may be slightly modified thereafter.
The secondary mold is obtained by performing operations such as coating, filling, and placing a curable member on the primary mold. For example, a user places the curable member on the primary mold. This shows a state in which a margin trimming portion having an arbitrary shape is formed. Since the curable member is in a state like a clay when forming the secondary mold, the molding is relatively easy.
At the time when the secondary mold is formed, the shapes of the abutment tooth surface and the margin line formed on the concave side surfaces of both molds and the trimming portion thereof may be measured using a contact / non-contact method. In this case, since it is sufficient to form a model, it is very easy to obtain shape data of a portion centered on the abutment tooth surface of the prosthesis.
[0006]
Another feature of the present invention is that
Around the abutment tooth is filled with a curable resin, which is meshed with each other to form a resin mass having an intermeshed shape and form a maximum protruding portion, and has a position information determined for the abutment tooth. Forming a model, acquiring the meshing surface data and the maximum prosperity data from the surface shape, and obtaining the missing portion shape data as a simplified shape of the missing portion space around the abutment tooth. According to this method, it is possible to reduce the time since only the main parts necessary for constructing the dental prosthesis are obtained as measurement data.
The simplified shape in the present invention indicates a reproducible two-dimensional shape, one-dimensional data value, or the like with a small number of parameters, and examples include a square, a rectangle, a circle, and a triangle. It is to be noted that the parameters are suitably 1 to 3, but more parameters may be used as appropriate according to the case where there is no problem in the calculation or other conditions.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
That is, a step of forming an abutment tooth model including a margin line,
Take an impression. (Silicone impression material, etc.)
After the impression material is cured, a silicone impression agent having low hardness and fluidity is used.
Flow around the abutment margin.
In order to take an impression more precisely, first, a silicone impression material is flowed around the entire margin, and then an impression is taken with a tray impression.
After the obtained impression is hardened, margin trimming is completed when gypsum is drained and extracted, and the combination of steps to obtain the abutment measurement model enables high precision and relatively easy formation of the abutment tooth model. I do.
The surface profile of the model is measured to determine the substructure of the dental prosthesis.
The measurement uses a contact probe used in CAD / CAM to convert a three-dimensional shape into a digital signal based on the state at the time of contact. In some cases, a non-contact type probe using laser light is used.
The measurement data is used to indicate the contact surface between the abutment tooth and the prosthesis, but may include other shape information (the upper structure and the shape of the contact portion between the abutment tooth).
[0008]
And forming a model upper part (denture) having an occlusal surface,
Working method (occlusion)
An operator such as a dentist and a dental hygienist is caused to create a Tek (temporary tooth).
For example, an instantly polymerized resin is mixed with a monomer and a polymer to form a rice cake, which is then bitten into the abutment so that the occlusal relationship with the opposing tooth can be understood.
Tek conditions required for measurement,
Conditions when the dentition is viewed from the occlusal surface,
In order for the dentist to determine the size of the teeth by himself, the two parameters XY are set by making the shape easy to obtain an approximate area. Have them decide the length of X. The length of Y is determined by the length of both adjacent teeth. If there are no adjacent teeth, have a dentist determine the size.
As a condition viewed from the side, ask them to cut down the places that they want to make the most.
[0009]
Have the dentist cut the marginal ridge to the point you want.
All necessary conditions are performed by the operator, and numerical symbolic data and parameters obtained by using a contact or non-contact probe as described above from the obtained model are transmitted to the dental prosthesis processing section. Send.
Based on the transmission data, the shape of the teeth is determined by increasing or decreasing the size according to the occlusal surface data prepared in advance, or by shaving the portion where the occlusal surface is fitted. It is preferable that the shape from the maximum protuberance to the margin line is numerically complemented by a curved surface that is relatively close to a plane.
The method of finally shaving the occlusal surface data and the abutment tooth data together may be a conventional method.
[0010]
【Example】
An embodiment of the present invention will be described in detail with reference to the drawings.
In FIG. 2, a cross-sectional view is partially used.
In FIG. 2A, an abutment tooth 21 having a margin line 22 is formed by a dentist or the like.
KS1 and KS2 are unintended adjacent teeth, and KS3 is a gingival part.
Next, as shown in FIG. 2B, only the vicinity of the margin line 22 of the abutment tooth 21 is filled with the curable member to form the local filling portion 23. The above-mentioned impression material is used for the curable member.
Next, as shown in FIG. 2C, the portion including the adjacent teeth KS1 and KS2 is further filled with a curable resin to form the impression portion 24. The impression part 24 is formed by filling the impression material at least to the extent that the distance and the shape between the adjacent teeth and the prosthetic part can be obtained.
After curing, it is removed and inverted as shown in FIG. 21S is a copied abutment tooth surface, 22S is a copied margin line, and KS1S and KS2S are adjacent tooth concave portions formed by copying.
[0011]
Further, as shown in FIG. 2 (e), the curable resin is filled into the concave portions formed by the adjacent teeth to form a raised mass state 25, and the annular convex portion 26 for margin trimming is formed. I do.
The annular trimming portion 26 for margin trimming is created by a processor such as a dental technician while forming a massive state. Since the mass state 25 is provided to form the margin trimming annular convex portion 26, the curable member is not particularly formed by filling the adjacent tooth concave portions KS1S and KS2S with various methods. I can take it.
The following method is proposed as a method for more accurately setting a margin line.
In other words, the liquid material heated and melted (hardened when cooled) (for example, dental paraffin WAX) is poured into the marginal line portion and solidified in FIG. 2D to obtain the concave abutment tooth surface of FIG. Since 22S is buried and extinguished, the bulk state 25 of FIG. 2E can be further covered over 22S. After the bulk state 25 is formed, the above-described curable liquid material is further added. A sharper margin line 31 as shown in FIG. 2 (h) can be obtained by adding the filling or taking out the curable liquid material 22S once cured and filling the curable member again. is there. This enables accurate detection of a margin line by a contact probe and easy detection of a feature point in non-contact measurement.
At this point, since all the elements for obtaining the abutment tooth model have already appeared in this mold, this mold may be measured directly or in contact or non-contact.
[0012]
Next, an abutment tooth model forming member is formed as shown in FIG.
That is, the above-described hardening member for forming an abutment tooth model (for example, cemented dental plaster) is filled, and the upper shape in the figure is arbitrarily formed.
FIG. 2 (g) shows this extracted. In the model body 29, reference numeral 27 denotes an abutment tooth surface and a prosthesis contact surface, reference numeral 28 denotes a margin line as a contact boundary portion with the prosthesis, and reference numeral 30 denotes a margin trimming portion.
As described above, by forming the local filling portion 23, an accurate impression of the margin line 30 can be obtained, and trimming can be performed by embedding a curable member, so that adjustment is relatively easy. The measurement of the surface shape of the model shown in FIG. 2 (g) is, for example, performed by a probe moving in a state horizontal in the Z direction as shown in FIG. 1 (2).
[0013]
Next, FIG. 3 shows a process for obtaining superstructure data according to the embodiment of the present invention. In FIG. 3, a cross-sectional view is partially used.
FIG. 3A shows a state in which an upper portion 31 made of a curable resin is filled on an abutment tooth 32.
In this case, the upper portion 31 made of the curable resin is in an uncured state, and is deformed by being engaged.
FIG. 3B shows a state at the time of occlusion.
KS4 to KS6 are upper dentitions. The upper part 31 made of a curable resin. The upper part 31 having the occlusal surface 33 is formed as shown in FIG.
[0014]
Thereafter, the operator performs a process for adjusting the surface, and obtains an adjustment occlusal surface such as 34 in order to obtain a marginal ridge.
In FIG. 2E, the abutment tooth surface is viewed from above, but in this state, the operator measures the distance 36 (Y) between adjacent teeth, and further measures the width of the adjacent teeth. From this, the width 35 (X) of the prosthesis is obtained.
At this time, X and Y are assumed to have a shape corresponding to an area easily obtained from these two parameters, and the measurement positions of the parameters are determined based on the shapes.
[0015]
Next, from the shape of the upper part 31, the operator performs processing for obtaining the maximum ridge 37.
From the upper model and the abutment tooth model obtained by the processing operation of the operator, the margin line and the distance data 38 of the maximum protruding portion 37 are obtained.
Alternatively, the distance between the margin line and the maximum protuberance may be obtained from the position information of the upper model attached to the abutment tooth (such as a value 39 indicating how much space is provided with respect to the margin line).
In some cases, this distance may be the distance between the occlusal surface and the margin line.
[0016]
This occlusal surface is measured and converted into data by using, for example, a contact probe shown in FIG. 1 (2), and the data and the X and Y parameters together with the abutment tooth data 21, the margin line data 22, and the distance data are converted into a computer The prosthesis block is subjected to three-dimensional processing to virtually create and convert the prosthesis shape into data. Based on the data, the prosthesis block is subjected to processing such as grinding. In this way, minimal measurements and quantification provide enough data to produce a dental prosthesis.
[0017]
The distance between the margin line and the maximum protuberance may be obtained, for example, by measuring the surface of the abutment tooth model in a contact or non-contact manner with the denture model being covered.
From the shape data and parameter data obtained from the abutment tooth model or the abutment impression model and the upper structure model, the shape data of the entire dental prosthesis is obtained by computer processing, and the dental prosthesis data is obtained. Based on the above, for example, using a NC machine tool or the like, a prosthesis preparation block is subjected to processing such as grinding and cutting to obtain a target dental prosthesis.
In this case, as the apparatus to be used, an apparatus disclosed in Japanese Patent Application Laid-Open No. H10-58281, a system disclosed in International Publication No. WO01 / 91664, and the like are suitably used. In the present invention, the place where the measurement step for measuring and converting the dental prosthesis model shape shown in FIGS. 2 and 3 into data and the processing step for processing the prosthesis block based on the data are separated. An operator such as a dentist is equipped with a measuring device based on the data conversion process, and a processor such as an organization, institution or service provider specializing in the processing process is provided. In some cases, a system connected via data transmission means is used.
According to this system, an operator forms a model, measures the surface of the model and converts it into measurement data, and transmits the measurement data to a processor using the data transmission means.
The processor receives the data, creates a prosthesis based on the data, and sends the prosthesis to the operator by mail, courier service, bringing it with the user, or the like.
Such a system can reduce the economical burden on the operator and can avoid the noise generated when processing the block. In addition, the method of the present invention facilitates the creation of a model while providing accurate data, thereby eliminating the need for an operator to acquire specialized knowledge for creating a model.
[0018]
【The invention's effect】
As described in detail above, the present invention realizes highly accurate detection of margin lines and simple margin trimming, and enables the production of a sufficient prosthesis with minimum data and parameters. Having.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a conventional example of the present invention.
FIG. 2 is a diagram for explaining an embodiment of the present invention.
FIG. 3 is a diagram for explaining an embodiment of the present invention.
[Explanation of symbols]
21 Abutment tooth surface 22 Margin line 23 Local filling part 24 Impression part 25 Bulk part 26 Margin trimming 27 Abutment tooth model 31 Upper part 32 Abutment tooth surface 33 Occlusion surface 34 Adjusting occlusal surface

Claims (4)

A method of forming a dental prosthesis in which a hardening member is locally arranged in a margin line portion of an abutment tooth, and then the hardening member is arranged around the abutment tooth to form an abutment tooth model. A primary mold is formed based on the shape of the abutment tooth and its periphery, and a model is created for obtaining the abutment tooth data by forming a secondary mold by further forming around the margin line of the primary mold. A method for forming a dental prosthesis. Around the abutment tooth is filled with a hardening resin, and the two are engaged with each other to form a resin mass having an occlusal surface shape, form a maximum protruding portion, and have a position information determined for the abutment tooth. A dentist by forming a model, acquiring occlusal surface data and maximum prosperity data from the surface shape, and obtaining the missing portion shape data as a simplified shape of the missing portion space around the abutment tooth Of forming a prosthesis for medical use. The margin line data, the surface data obtained directly or indirectly, the maximum ridge data, and the missing part shape data are combined, and other necessary data are complemented numerically to form the shape of the entire dental prosthesis. The method for forming a dental prosthesis according to claim 1, wherein data is obtained.

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