JP5837522B2 - Abutment design method and abutment manufacturing method - Google Patents

Description

  The present invention relates to an abutment design method used for dental implant treatment, and an abutment manufacturing method.

  In recent years, dental implant treatment that has advantages in many respects such as functionality, aesthetics, and operability is widely used as a treatment method in the case of complete or partial loss of teeth.

Dental implants are artificial roots (sometimes called fixtures, implants, etc.) that are embedded in the jawbone (alveolar bone) of the missing part of the tooth and attached to one end of the artificial dental root. And a dental prosthesis that simulates a tooth that is attached to and held by the abutment that protrudes to the inside of the oral cavity (sometimes called an abutment or the like).
That is, the abutment functions as a member that connects the artificial tooth root and the dental prosthesis.

  The outer shape of the abutment is a cylindrical shape or a truncated cone shape that is close to a cylinder, and its diameter once expands from the artificial root side toward the inside of the oral cavity, and further maintains the diameter toward the inside of the oral cavity or shrinks the diameter. The shape to be common is common. The diameter-expanded part on the artificial tooth root side is a part that fits in the gingiva, and the dental prosthesis is fixed to a part (a part where the diameter is maintained or a part where the diameter is reduced) located inside the oral cavity. The boundary between the part that expands and the part that contracts (or the part where the diameter is maintained) may be called a margin line.

  The shape of such an abutment can be determined in detail for each patient. In recent years, for example, using CAD / CAM as described in Patent Document 1, the size and thickness of the abutment, and the angle with the artificial tooth root. It is possible to provide an abutment having a shape suitable for an individual patient such as a complicated shape of the surface. However, in the case of using such CAD / CAM, a model is created from taking an impression, this is measured and converted into data, and the abutment is designed in detail by a computer. A procedure is required in which the original data is transferred to the NC machine tool for production. Therefore, there are problems that the process for producing the abutment is complicated and takes time, and the cost of investment and maintenance of the equipment is also large.

  On the other hand, Patent Document 2 discloses a technique using a model set that is divided into one part, the other part, and two parts across a margin line. This prepares many different shapes for each of the two parts, determines the most appropriate combination based on patient information, and creates an abutment based on this. According to this, an abutment can be manufactured more easily and quickly without the need for impression taking, model preparation, three-dimensional measurement, and the like.

JP 2002-224142 A JP 2010-187884 A

  However, in the technique described in Patent Document 2, it is necessary to prepare a large number of models, and there is a trouble of combining two parts. On the other hand, if the number of model parts is reduced in order to avoid complication of combination, some prepared parts may not be appropriate depending on the patient.

  Accordingly, the present invention provides an abutment design method and an abutment manufacturing method in which the abutment can be more easily produced and the shape of the abutment is in accordance with the individual situation of the patient. The task is to do.

  The present invention will be described below. Here, for ease of understanding, reference numerals attached to the drawings are described in parentheses, but the present invention is not limited thereto.

The invention according to claim 1 includes a fitting part (11) with an artificial tooth root (2), a part (12) arranged in the gingiva, and a part (13) inserted into the dental prosthesis (3). A method for designing an abutment (10) having a margin line (10a) formed at a boundary between a portion to be placed in a gingiva and a portion to be inserted into a dental prosthesis, comprising: Position on the line connecting the reference points (20, 21, 22, 23) set to 1 to 4 on the surrounding gingival surface and the oral cavity inner end surface of the artificial tooth root, and the margin line should be arranged The distance between the height measurement position (25, 26, 27, 28) and the inner end surface of the artificial tooth root is defined as the margin line height (H ₁ , H ₂ ), and the axis and height measurement position of the artificial tooth root among distances, largest of the margin line maximum radius (R ₁₎ And, from the oral cavity inner end of the artificial tooth root to be mounted abutment distance abutment height up oral inner end with (H _A), at the reference point direction, abutment to the axis of the incoming direction embedding the dental implant The abutment design method determines the shape of the abutment based on the margin line height, the margin line maximum radius, the abutment height, and the inclination angle, where the angle of inclination is the inclination angle (θ ₁ ). is there.

  According to a second aspect of the present invention, in the abutment design method according to the first aspect, the margin line height, the margin line maximum radius, the abutment height, and the inclination with respect to the shape data of the reference abutment Based on the angle, the shape data of the reference abutment is changed to obtain the shape data of the abutment.

  According to a third aspect of the present invention, the abutment shape obtained by the abutment design method according to the first or second aspect is transmitted as data to an NC-controlled machine tool, and the abutment is machined based on the data. It is a manufacturing method of a ment.

  According to the present invention, it is possible to produce an abutment that is advantageous from the viewpoint of time, labor, and cost while making use of a patient-specific shape without preparing a wax mold or preparing a model set of a plurality of shapes in advance. .

FIG. 2 is a diagram illustrating the structure of an implant 1. It is a figure explaining the structure of abutment. It is a figure explaining the flow of manufacturing method S1 of the abutment. It is a figure explaining the flow of information acquisition process S10. It is a figure explaining a reference point and margin line height. It is a figure explaining a margin line radius. It is a figure explaining abutment height. It is a figure explaining an inclination angle.

  The above-described operation and gain of the present invention will be clarified from embodiments for carrying out the invention described below. Hereinafter, the present invention will be described based on embodiments shown in the drawings. However, the present invention is not limited to these embodiments.

  First, one form of abutment 10 will be described. FIG. 1 is a diagram schematically showing the structure of an implant 1 including an abutment 10. The implant 1 includes an artificial tooth root 2, an abutment 10, and a dental prosthesis 3.

  The artificial tooth root 2 is also referred to as a fixture or an implant body, and is a member that is embedded in the alveolar bone of the portion where the tooth has been lost and serves as a basis for appropriately fixing the entire implant 1 in the oral cavity. Here, a known artificial tooth root 2 can be used.

  The abutment 10 is fixed to the artificial tooth root 2 on the jawbone side (lower end side in FIG. 1), and a dental prosthesis 3 such as an artificial crown is attached to the inner side of the oral cavity (upper end side in FIG. 1). That is, the abutment 10 functions as a member that connects the artificial tooth root 2 and the dental prosthesis 3.

  FIG. 2 shows the appearance of the abutment 10. As can be seen from FIG. 2, the abutment 10 includes an artificial root fitting portion 11, a gingival portion 12, and a dental prosthesis insertion portion 13.

The abutment 10 is a cylindrical body close to a cylinder, and is configured such that a screw for attaching to the artificial tooth root 2 can be inserted therein. On the other hand, the outer shape of the abutment 10 is as follows.
The artificial tooth root fitting portion 11 is a part that is disposed at the end of the abutment 10 that is closest to the artificial tooth root 2 and is fitted inside the artificial tooth root 2. In FIG. Yes. The shape for the fitting is determined by the form of the artificial tooth root 2.
The gingival part 12 is a site | part continuously formed in the direction which becomes an oral cavity inner side from the artificial tooth root insertion part 11, and is comprised so that the diameter may expand toward the oral cavity inner side from an artificial dental root side. The gingival portion 12 is a part that fits in the gingiva.
The dental prosthesis insertion part 13 is a part formed continuously from the gingival part 12 to the inside of the oral cavity, and its diameter is maintained or reduced. In this embodiment, the diameter is reduced as can be seen from FIGS. The dental prosthesis insertion portion 13 is inserted into the dental prosthesis 3 to fix and hold the dental prosthesis 3.
A margin line 10 a is formed at the boundary between the gingival part 12 and the dental prosthesis insertion part 13.

  The abutment 10 as described above can be manufactured by a design method and a manufacturing method described later.

  A dental prosthesis 3 shown in FIG. 1 is a member that substantially compensates for a missing portion of a dentition, such as an artificial crown, for example, and has a shape imitating a tooth, so that the shape and texture of the tooth are reproduced. Has been. As such a dental prosthesis 3, a known one can be used.

  The abutment 10 described above can be designed and manufactured as follows. FIG. 3 shows a flow chart showing the steps of the abutment manufacturing method S1. As can be seen from FIG. 3, the abutment manufacturing method S <b> 1 includes an information acquisition step S <b> 10, a shape design step S <b> 20, and an abutment processing step S <b> 30.

  The information acquisition step S <b> 10 is a step of acquiring information that is the basis of what shape the abutment 10 should be formed in. FIG. 4 shows the flow of the information acquisition step S10. In this embodiment, the information acquisition step S10 includes a reference point setting S11, a margin line height measurement S12, a margin line maximum radius measurement S13, an abutment height measurement S14, and an inclination angle measurement S15.

  The reference point setting S11 is a step of setting a reference point for acquiring information. The figure demonstrated in FIG. 5 was shown. Fig.5 (a) is the figure which planarly viewed the artificial tooth root 2 embed | buried under a patient's jawbone from the oral cavity inner side. Accordingly, FIG. 5A shows that the end face of the artificial tooth root 2 on the side fitted to the abutment 10 is exposed to the inside of the oral cavity. FIG. 5B is a front view of FIG. 5A from the palate side. FIG. 5B shows that the artificial tooth root 2 is embedded in the jawbone at the bottom between the gingiva.

  The reference point is a point used as a reference for obtaining information in the information acquisition step S10. Therefore, the larger the number of reference points, the greater the amount of information on the patient's oral form, and the abutment approaches the patient's oral form. On the other hand, it is possible to provide an abutment having advantages from the viewpoint of time and cost when the number of reference points is small. As described above, the number of reference points can be appropriately set according to the circumstances. Among these, as described below, by taking four reference points, an abutment having a good balance between the two can be provided. One example is described below.

As can be seen from FIG. 5A, in this example, when the embedded artificial tooth root 2 is viewed in plan, the reference point 20 on the left side in the dentition direction and the reference point 21 on the right side in the dentition direction when the artificial tooth root 2 is centered. The reference point 22 was taken on the cheek side, and the reference point 23 was taken on the palate side. And each reference point 20, 21, 22, 23 is provided in the site | part used as the vertex of the gingiva in each direction so that it may appear with respect to the reference points 20, 21 in FIG.5 (b). By providing a reference point at the top of the gingiva, the position of the reference point becomes more accurate and clear. In addition, it is preferable that the reference points are set equally by the number provided around the entire circumference of the artificial tooth root 2.
In this example, the four directions are determined as described above. However, the direction is not necessarily limited to this, for example, the direction based on the shape of the portion of the artificial tooth root 2 to which the fitting portion of the abutment 10 is fitted, Combinations of these can be mentioned.
In addition, although an example in which a reference point is set at the vertex of the gingiva is given here, the reference point is not limited to this as long as a reference point is determined. This includes, for example, adjacent teeth. However, since the measurement error can be minimized when the reference point is closer to the artificial tooth root, the vertex of the gingiva has been described as a preferable part here.

The margin line height measurement S12 is performed on the upper surface of the artificial tooth root 2 where the margin line 10a of the abutment 10 should be positioned on the line connecting the axis center of the artificial tooth root 2 and the reference points 20, 21, 22, 23. It is the process of measuring the distance from. This will be described more specifically with reference to FIGS. 5 (a) and 5 (b).
First, consider the reference point 20. As can be seen from FIGS. 5A and 5B, the height measurement position 25 is set on a line connecting the axis center of the artificial root 2 and the reference point 20. The height measurement position 25 is a position where the margin line 10a should be placed when the abutment 10 is attached. The position of the margin line 10a is determined as usual, and is basically determined by a dentist.
Then, as represented by H ₁ in FIG. 5B, a height H ₁ that is a distance from the upper end of the artificial tooth root 2 to the height measurement site 25 is measured.
Considering the reference point 21 in the same manner, the height H _{2 at the} height measurement position 26 on the reference point 21 side (see FIG. 5B), and the height H _{3 at the} height measurement position 27 on the reference point 22 side (see FIG. 5B). (Not shown) and height H ₄ (not shown) by the height measurement position 28 on the reference point 23 side can be obtained.

  The margin line maximum radius measurement S13 is a step of measuring the maximum radius of the margin line 10a. The figure demonstrated in FIG. 6 was shown. 6A is a view from the same viewpoint as FIG. 5A, and FIG. 6B is a view from the same viewpoint as FIG. 6B. This will be specifically described with reference to FIGS. 6 (a) and 6 (b).

Here, as can be seen from FIGS. 6 (a) and 6 (b), the distance between the axis of the artificial tooth root 2 and the height measurement positions 25, 26, 27, 28 is set to the margin line radius R ₁ , at each reference point, Let R ₂ , R ₃ , R ₄ . Here, the margin line radii R ₁ , R ₂ , R ₃ , and R ₄ are determined by using a member 30 that extends the artificial tooth root 2 in the axial direction as shown in FIG. 6B, for example. What is necessary is just to measure the distance between and the height measurement position.
Then, the largest margin line radius R ₁ , R ₂ , R ₃ , R ₄ at each of the obtained reference points 20, 21, 22, 23 is set as the margin line maximum radius R. Here, R ₁ is the margin line maximum radius R.

As shown in FIG. 7, the abutment height measurement S <b> 14 is a step of measuring a height _HA from the oral cavity inner end surface of the artificial root 2 to the oral cavity inner tip of the abutment 10 to be attached. The position of the inner end of the oral cavity of the abutment 10 is determined so that the dental prosthesis 3 can be inserted appropriately.

The inclination angle measurement S15 is a step of measuring the inclination of the axis of the abutment to be designed with respect to the axis of the artificial tooth root 2. The figure for demonstrating in FIG. 8 was shown.
Here, the inclination of the axis of the abutment 10 and the axis of the artificial tooth root 2 in the directions of the reference points 20, 21, 22, 23 is measured. That is, the inclination angles θ ₁ , θ ₂ , θ ₃ , θ regarding how much the axis of the artificial tooth root 2 is inclined with respect to the abutment 10 to be designed in each direction of the reference points 20, 21, 22, 23. ₄ is measured. FIG. 8 shows the inclination with respect to the direction of the reference point 20 and represents the case of the inclination angle θ ₁ . Here, the inclination angles θ ₁ , θ ₂ , θ ₃ , and θ ₄ are determined by using a member 30 that extends the artificial tooth root 2 in the axial direction as described above, for example, as shown in FIG. What is necessary is just to measure the angle | corner which the abutment which is going to design as an embedding direction of the tooth root 2 forms.

In the information acquisition step S10, information is acquired as described above. As can be seen from this, when acquiring information, it is not necessary to convert the data into a model or a three-dimensional measuring instrument. Therefore, the effort for acquiring information is greatly suppressed, and the abutment can be manufactured more smoothly. Further, the measurement itself is the same as the procedure for producing a conventional dental prosthesis, and an expensive apparatus such as a three-dimensional measuring instrument is not required, so that there is an advantage from the viewpoint of cost.
On the other hand, since the abutment is created from the measured patient-specific information, it is possible to create an abutment having a shape that matches the intraoral shape of the patient.
That is, according to the present invention, it is possible to provide an abutment that is advantageous in terms of time, labor, and cost, while corresponding to a patient-specific shape within a predetermined range.

  Returning to FIG. 3, the shape design step S20 will be described. In the shape design step S20, based on the information obtained in the information acquisition step S10, for example, based on the three-dimensional graphic of the intraoral shape displayed on the graphic display device using a graphic display device such as a CRT screen of a computer. It is designed so that it has the shape of a proper abutment.

Specifically, first, the inclination of the gingival part 12, which is the basis of the graphic display device, is constant, the inclination of the dental prosthesis insertion part 13 is constant, has a reference height, and the height of the margin line. A three-dimensional graphic display of a substantially cylindrical reference abutment whose length is constant around the abutment is performed.
Then, the information obtained in the information acquisition step S10, including the reference point setting S11, the margin line height measurement S12, the margin line maximum radius measurement S13, the abutment height measurement S14, and the inclination angle measurement S15, is described above as a reference. It is applied to the abutment and displayed in three dimensions on the graphic display device.

Thereafter, fine adjustment is performed so that the shape of the target abutment is obtained on the three-dimensional graphic. At this time, for example, when there is a gap between three pieces of information such as a combination of numerical values of the margin line height and the margin line maximum radius between multiple pieces of information, if there is a conflict as 3D data, an error display setting In addition, the operator may be able to appropriately modify the shape of the abutment.
Further, it is also preferable that fine adjustment can be made to a shape that can be easily cut even if no contradiction occurs.

  Then, compare the size of the material set by automatic processing with a computer and the size of the abutment to be manufactured. If the designed abutment is larger than the material to be used, change the rest setting position or use it Make adjustments such as changing to a larger one.

  After determining the conditions for designing the dental prosthesis as described above, the final automatic calculation (so-called CAD calculation) is performed, and the design data, which is the calculation result, is stored in the computer's memory as a digital signal. Or an external storage medium such as a magnetic disk or MO.

  The abutment processing step S30 is a step of producing the abutment 10 from the shape information obtained in the shape design step S20. Details are as follows.

The obtained design data, which is shape information, is transmitted as a machining command to an NC-controlled cutting / grinding machine. After that, a cutting block material in which a fitting part having the same shape as the fitting part of the abutment to be produced is formed in advance is selected and attached to an automatic cutting machine, and a cutting / grinding tool such as a carbide bar is used. An abutment is manufactured by cutting and grinding based on the design data. As the material for the cutting block, a titanium alloy, a ceramic before and after firing, a composite resin, or the like is preferably used.
Here, the example in which the fitting part is formed in advance has been described. However, the present invention is not limited thereto, and the fitting part may be processed in this step.

  As can be seen from the above, the abutment design method and the abutment manufacturing method described above enable an abutment that is advantageous in terms of time, labor, and cost while utilizing the patient-specific shape.

DESCRIPTION OF SYMBOLS 1 Implant 2 Artificial root 3 Dental prosthesis 10 Abutment 20, 21, 22, 23 Reference point 25, 26, 27, 28 Height measurement position

Claims (3)

Boundary between a portion to be inserted into the gingiva and a portion to be inserted into the dental prosthesis having a fitting portion with the artificial tooth root, a portion disposed in the gingiva, and a portion to be inserted into the dental prosthesis A method of designing an abutment in which a margin line is formed,
It is a position on the line connecting the reference points set to 1 to 4 points on the gingival surface around the embedded artificial tooth root and the oral cavity inner end surface of the artificial tooth root, and the margin line should be arranged The distance between the height measurement position and the oral cavity inner end surface of the artificial tooth root is the margin line height,
Of the distance between the axis of the artificial tooth root and the height measurement position, the maximum one is the margin line maximum radius,
The abutment height is the distance from the inner oral end of the artificial tooth root of the abutment to be attached to the inner oral tip,
When the angle at which the abutment is inclined with respect to the axis of the artificial tooth root in the reference point direction is an inclination angle,
An abutment design method for determining a shape of the abutment based on the margin line height, the margin line maximum radius, the abutment height, and the inclination angle.   For the shape data of the reference abutment, change the shape data of the reference abutment based on the margin line height, the margin line maximum radius, the abutment height, and the inclination angle, The abutment design method according to claim 1, wherein shape data of the abutment is obtained.   An abutment manufacturing method in which the abutment shape obtained by the abutment design method according to claim 1 or 2 is transmitted as data to an NC-controlled machine tool, and the abutment is processed by the data.

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