JPS6352895B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dental parallelizer, and in particular, to a dental parallelizer, which is configured to issue an alarm when the axis of the grinder and the axis of the abutment tooth deviate from parallelism by more than a certain angle. The present invention relates to a dental parallelizer.

[Conventional technology]

Abutment tooth preparation is an important fundamental technique in manufacturing a crown prosthesis, and involves providing an appropriate taper to the side wall of the abutment tooth. Generally, the taper that should be given to the side wall of the abutment tooth is approximately 5 to 10 degrees with respect to the axis of the abutment tooth.
The rod-shaped grinder used for preparing the abutment tooth is usually tapered at 5 to 10 degrees with respect to its axis, and the handpiece to which the grinder is attached is simply moved parallel to the abutment tooth to form the abutment tooth. As mentioned above, it is designed to be cuttable.

An example of a conventional dental parallelizer of this type will be explained with reference to FIG. In the conventional example shown in Figure 3,
The inclinometer 5 is attached by the clip 3 to the arm or handpiece 1A of the cutter 1 for the abutment tooth.
This inclinometer 5 can be freely tilted with respect to the handpiece 1A by means of a joint portion 4. At the time of starting cutting of the abutment tooth ST,
After making the axis of the conical grinder 2 attached to the tip of the handpiece 1A parallel to the axis Z--Z of the abutment tooth ST, the inclinometer 5 is made accurately horizontal. Inclinometer 5
is a type that, when tilted at a certain angle or more with respect to a horizontal plane, the internal conductive liquid comes into contact with the electrode and becomes conductive. Therefore, by connecting an alarm circuit externally, the shaft of the grinder 2 and the abutment tooth can be
An alarm is issued when the declination angle with the ST axis Z-Z exceeds a certain angle.

[Problem that the invention seeks to solve]

However, in such a conventional dental parallelizer, an alarm is output when the inclinometer 5 is tilted at a certain angle or more with respect to the horizontal plane, so if the abutment tooth ST side moves, the grinder Therefore, it becomes impossible to obtain a correct warning regarding the declination angle between the axes of ST and the abutment tooth ST. Therefore, the inclinometer 5
After aligning the and abutment tooth ST again as described above,
It is necessary to set the inclinometer 5 horizontally again, which has the disadvantage of poor operability.

Furthermore, since the alarm level is determined mechanically depending on the relationship between the electrodes in the inclinometer 5 and the conductive liquid, there is also the drawback that the alarm level cannot be set to match the working situation.

[Means for solving problems]

In the present invention, posture detectors 51 and 52 are attached to both the hand piece 1A having the grinder 2 of the abutment tooth cutter 1 and the abutment tooth side PA, and the posture detectors 51 and 52 output signals proportional to their inclinations. By taking the difference between both outputs of the detector, handpiece 1A
A dental parallelizer is characterized in that it calculates and outputs a relative inclination angle signal between the PA and the abutment tooth side PA, and detects whether or not this relative inclination angle signal exceeds a predetermined level. It is composed of

[Effect]

The dental parallelizer of the present invention includes, for example, two-axis inclinometers 51 and 52 that output signals proportional to the inclination angle.
is attached to both the handpiece 1A and the abutment tooth side PA, and based on their output signals, the relative angle between the handpiece 1A and the abutment tooth side PA is calculated, and whether or not it is greater than a certain angle. The above-mentioned problem is solved by detecting the above-mentioned amount and issuing an alarm or stopping the driving source of the grinder 2 when the amount exceeds the limit.

〔Example〕

Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention. First, its configuration will be explained. 1 is the abutment tooth ST
1A is its arm or handpiece, and 2 is a conical grinder attached to the tip of the handpiece 1A. 51
is the attitude detector attached to handpiece 1A,
For example, it is a two-axis inclinometer, and is designed to be detachable and attachable to the handpiece 1A, and can be tilted freely.

Reference numeral 52 denotes a posture detector, such as a two-axis inclinometer, which is attached to, for example, a patient (hereinafter referred to as the abutment tooth side PA) having the abutment tooth ST via an attachment such as glasses SP. It is designed to be detachable from the abutment tooth side PA and can be tilted freely. The outputs of the inclinometers 51 and 52 are:
The signal is sent to the control circuit 7.

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be explained. First, the inclinometer 52 attached to the abutment tooth side PA is made approximately horizontal in advance. next,
When the axis of the grinder 2 is made approximately parallel to the axis ZZ of the abutment tooth ST, the inclinometer 51 is attached to the handpiece 1A and adjusted so that it is approximately horizontal.
The inclinometers 51 and 52 are both biaxial inclinometers, for example, as described above, and output signals proportional to the inclination angles in the X direction and the Y direction, which are orthogonal to each other.

The control circuit 7 uses the signals sent from the inclinometers 51 and 52 to calculate and display the relative inclination angles of the two inclinometers 51 and 52.

At the time of starting cutting of the abutment tooth ST, after making the axis of the grinder 2 parallel to the axis Z-Z of the abutment tooth ST, while looking at the indicator (not shown) attached to the control circuit 7, , the inclinometer 51 or 5 so that the relative inclination angle between the two inclinometers 51 and 52 is zero.
Adjust 2.

During the subsequent cutting work of the abutment tooth ST,
The control circuit 7 connects the handpiece 1A and the abutment tooth side PA.
By calculating how much the relative inclination angle between
Calculate the argument with respect to the axis Z-Z. Furthermore, the control device 7 controls the calculated axis of the grinder 2 and the abutment tooth.
If the declination angle between the ST axis and the Z-Z axis exceeds a predetermined level, an alarm will be issued. In addition, at the same time as issuing an alarm, or instead of issuing an alarm,
The driving source for the grinding 2 may be stopped.

Next, an example of the control circuit 7 of the present invention will be explained with reference to FIG.

First, its configuration will be explained. An adder circuit 71X in the control circuit 7 receives an inclination signal 51X in the X direction from the inclinometer 51 attached to the handpiece 1A and an inclination signal 52X in the X direction from the inclinometer 52 attached to the abutment tooth side PA. , the difference between the two is taken, and a relative inclination angle signal in the X direction between the hand piece 1A and the abutment tooth side PA is output. The adding circuit 71Y receives a Y-direction tilt signal 51Y from the inclinometer 51 attached to the handpiece 1A and a Y-direction tilt signal 52Y from the inclinometer 52 attached to the abutment tooth side PA, and calculates the difference between the two. and outputs a relative inclination angle signal in the Y direction between the hand piece 1A and the abutment tooth side PA.
74X and 74Y are filter circuits, respectively;
The outputs of adder circuits 71X and 71Y are filtered. 75 is a time constant setting circuit that sets each filter time constant of the filter circuits 74X and 74Y. 76 is an alarm circuit, and a filter circuit 74
It receives the outputs of X and 74Y, and outputs an alarm when at least one of them exceeds the level set by the alarm level setting circuit 77. Also, at the same time as outputting the alarm or instead of issuing the alarm, the cutting tool 1
The drive source of the grinder 2 may be stopped. 78
X and 78Y are indicators, respectively, which display the relative inclination angles of the hand piece 1A and the abutment tooth side PA in the X and Y directions, which are the outputs of the adder circuits 71X and 71Y, respectively.

Next, the operation of the control circuit 7 will be explained.

First, the adder circuit 71X receives the inclination signal 5 in the X direction from the inclinometer 51 attached to the handpiece 1A.
1X and inclinometer 5 attached to the abutment tooth side PA
The difference between the two inclination signals 52X in the X direction is calculated, and the relative inclination angle signals in the X direction of the two inclinometers 51 and 52 are output. Similarly, the adder circuit 71Y generates Y-direction tilt signals 51Y and 5 of the two tiltmeters 51 and 52.
2Y and calculate the Y of the two inclinometers 51 and 52.
Outputs the relative tilt angle signal of the direction. Display circuit 78
X and 78Y indicate the outputs of the adder circuits 71X and 71Y, respectively, that is, the relative inclination angles of the two inclinometers 51 and 52 in the X direction and the Y direction. The display method is not particularly limited, but for example, numerical values, LED,
Display with bar graph, meter, etc.

At the time of starting cutting of the abutment tooth ST, first, the inclinometer 51 attached to the handpiece 1A and the inclinometer 52 attached to the abutment tooth side PA are
Keep each roughly horizontal. Next, handpiece 1
The shaft of grinder 2 attached to A is the abutment tooth
After making it parallel to the ST axis Z-Z, adjust the inclinometer 51 or 52 while watching the indicators 78X and 78Y so that the relative inclination angle between the two inclinometers 51 and 52 is zero. . Therefore, during the subsequent cutting of the abutment tooth ST, the two inclinometers 51,
52, i.e., addition circuits 71X and 7
The output of 1Y represents the deviation angle between the axis of the grinder 2 and the axis ZZ of the abutment tooth ST.

The filter circuits 74X and 74Y filter the declination signals in the X direction and the Y direction between the axis of the grinder 2 and the axis Z-Z of the abutment tooth ST, which are the outputs of the adder circuits 71X and 71Y, respectively, and eliminate disturbances. A correct declination signal is obtained by removing high frequency components due to vibrations, etc., and an appropriate delay time is provided for alarm detection by the alarm circuit 76. The filter time constant setting circuit 75 is a circuit for setting each filter time constant of the filter circuits 74X and 74Y to a desired value, and is for selecting an appropriate alarm detection response time according to the work situation. .

The alarm circuit 76 connects the shaft and abutment teeth of the grinder 2.
For example, when the declination angle with respect to the axis Z-Z of the ST exceeds a predetermined alarm level, an alarm is output.
When either filter circuit 74X or 74Y exceeds the level set by alarm level setting circuit 77, an alarm is output. By allowing the alarm level to be freely set using the alarm level setting circuit 77, for example, during training for abutment tooth formation, it is possible to select an alarm level according to the skill of each trainee, which improves training effectiveness. This is to increase the

The alarm circuit 76 combines the outputs of the filter circuits 74X and 74Y, and issues an alarm when the magnitude of the declination between the axis of the grinder 2 and the axis Z-Z of the abutment tooth ST exceeds an alarm level. It may also be possible to output .

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained.

(1) By attaching an inclinometer not only to the handpiece but also to the abutment tooth side, even if the abutment tooth side moves, it is possible to obtain the true deviation angle between the axis of the grinder and the axis of the abutment tooth. can.

(2) By passing the declination signal between the axis of the grinder and the axis of the abutment tooth through a filter circuit whose time constant can be set arbitrarily, high frequency components caused by external vibrations are removed and a correct declination signal is obtained. , the response time for alarm detection can be selected according to the work situation.

(3) By making it possible to freely set the alarm level, for example, when training for abutment tooth preparation, the alarm level can be set according to the skill of each trainee, and the effectiveness of the training can be improved. can be increased.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an example of a dental parallelizer according to the present invention, FIG. 2 is a block diagram of an example of its control circuit, and FIG. 3 is a schematic diagram of an example of a conventional dental parallelizer. be. In the figure, 1 is a cutter, 1A is a handpiece, 2 is a grinder, 7 is a control circuit, 51, 52
is a posture detector, 71X, 71Y are addition circuits, 74
X, 74Y are filter circuits, 75 is a time constant setting circuit, 76 is an alarm circuit, 77 is an alarm level setting circuit, 78X, 78Y is a display, ST is an abutment tooth, PA
indicates the abutment tooth side, and SP indicates the glasses.

Claims (1)

[Scope of Claims] 1. In a dental parallelizer including a grinder of an abutment tooth cutter and a handpiece having a posture detector thereof, a posture that outputs a signal proportional to the inclination of the abutment tooth side as well. By attaching the detector and taking the difference between the outputs of the two attitude detectors using the addition circuit of the control circuit, the relative inclination angle signal between the handpiece and the abutment tooth side is calculated and output, and the relative inclination angle signal between the handpiece and the abutment tooth side is calculated and output. A dental clinic characterized in that an alarm circuit of the control circuit detects whether or not the tilt angle signal exceeds a predetermined level, and issues an alarm when the relative tilt angle signal exceeds the predetermined level. parallel former. 2. The dental parallelizer according to claim 1, wherein the drive source for the grinder is stopped when the relative inclination angle signal exceeds a predetermined level. 3. By passing the relative inclination angle signal between the handpiece and the abutment tooth side through a filter circuit, an appropriate delay is given to the alarm output, and the time constant of the filter circuit can be arbitrarily set. The dental parallelizer according to claim 1, characterized in that the response time can be freely selected. 4. The dental parallelizer according to claim 1, wherein the alarm generation level can be set arbitrarily. 5. The dental parallelizer according to claim 1, wherein the relative inclination angle between the hand piece and the abutment tooth side is displayed by a display.