JPS6352896B2 - - 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 for manufacturing abutment prosthesis, and involves imparting an appropriate taper to the side wall of the abutment tooth. in general,
The taper that should be applied to the side wall of the abutment tooth is approximately 5 to 10 degrees with respect to the axis of the abutment tooth. It has a taper of 5 to 10 degrees, and the abutment tooth can be cut as described above simply by moving the handpiece to which the grinder is attached parallel to the abutment tooth.

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 the axis of the conical grinder 2 attached to the tip of the handpiece 1A is made parallel to the axis ZZ 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 the inclinometer 5 at the start of cutting the abutment tooth ST is Leveling work has a direct effect on the accuracy of the alarm, so it must be done as accurately as possible. However, when leveling the inclinometer 5, it is necessary to hold both the axes of the grinder 2 and the abutment tooth ST parallel to each other while looking at the spirit level attached to the inclinometer 5. The disadvantages are that it is very difficult to operate and the horizontal accuracy is not very good.

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]

The present invention provides a hand piece 1A having a grinder 2 of an abutment tooth cutter 1 with a posture detector 5 which outputs a signal proportional to its inclination angle and which is detachably attached to the hand piece 1A so as to be freely tiltable. The output of the attitude detector at the time the reset switch operates is stored, and by taking the difference between the output of the attitude detector and the memorized output, the hand from the time the reset switch operates is determined. Parallel formation for dentistry, which calculates and outputs a declination signal of the handpiece, and detects whether the declination signal of the handpiece exceeds a predetermined level from the time when the reset switch is activated. It is made up of a container.

[Effect]

In the dental parallel formation of the present invention, a posture detector 5 such as a two-axis inclinometer that outputs a signal proportional to the inclination angle is attached to the handpiece 1A, and the abutment tooth
The inclination angle of the handpiece at the start of ST cutting is memorized, and it is detected whether the declination angle from that point exceeds a certain angle. The above problem is solved by stopping the drive source.

〔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. Reference numeral 1 indicates a cutting device for the abutment tooth as a whole, 1A is its arm or handpiece, and 2 is a conical grinder attached to the tip of the handpiece 1A. 5 is a posture detector attached to the handpiece 1A, for example 2
It is an axis inclinometer, and for handpiece 1A,
It is removable and can be tilted freely.

The output of the inclinometer 5 is sent to a control circuit 7.

6 is a reset switch provided on the handpiece 1A, and when this reset switch 6 is activated,
A reset signal is sent to the control circuit 7. Note that the reset switch 6 may be provided in the control circuit 7.

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be explained. The shaft of the conical grinder 2 is attached to the abutment tooth ST.
The inclinometer 5 is attached to the handpiece 1A and adjusted so that it is approximately horizontal when the inclinometer 5 is approximately parallel to the axis Z-Z of (in this example, both axes coincide). The inclination angle 5 is, for example, a two-axis inclinometer as described above, and outputs a signal proportional to the inclination angle in the X direction and the Y direction, which are orthogonal to each other.

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, when the reset switch 6 is activated, a reset signal is sent to the control circuit 7. , the control circuit 7 stores the inclination angle of the handpiece 1A at that time.
During the subsequent cutting operation of the abutment tooth ST, the control circuit 7 calculates how much the inclination angle of the handpiece 1A has changed from the inclination angle of the handpiece 1A memorized at the time of reset, and calculates the equivalent value. Calculate the declination angle between the axis of the grinder 2 and the axis Z-Z of the abutment tooth ST. Furthermore, if the calculated deviation angle between the axis of the grinder 2 and the axis Z-Z of the abutment tooth ST exceeds a predetermined level (angle), the control circuit 7
It is starting to sound an alarm.

Incidentally, at the same time as issuing this alarm, or instead of issuing the alarm, the drive source of the grinder 2 of the cutting tool 1 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. 72X and 72Y
are hold circuits, and when the reset signal 61 from the reset switch 6 is input, the inclination signals of the inclinometer 5 in the X direction and the Y direction at that time are stored and outputted. 73X and 73Y are
They are adder circuits, and hold circuits 72X and 7
It receives the output signal of 2Y and the tilt signals of the inclinometer 5 in the X and Y directions, and outputs the difference between them. 74X and 74Y are filter circuits, respectively, and filter the outputs of the adder circuits 73X and 73Y. 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 filter circuits 74X and 74Y
When at least one of the two exceeds the level set by the alarm level setting circuit 77, an alarm is output. Further, at the same time as outputting the alarm, or instead of outputting the alarm, the drive source of the grinder 2 of the cutting tool 1 may be stopped. 78X and 78Y are indicators, respectively, and a filter circuit 74X
and 74Y at the time when the reset switch 6 of the handpiece 1A is activated.
Displays the inclination angle of the direction and the deviation angle between the relative inclination angle of the X and Y directions during the cutting operation after that point.

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

First, the inclinometer 5 attached to the handpiece 1A is kept approximately horizontal. At the time of starting cutting of the abutment tooth ST, the reset switch 6 is activated after the axis of the grinder 2 attached to the handpiece 1A and the axis ZZ of the abutment tooth ST are made parallel. At this time, the reset switch 6 sends a reset signal 61 to both hold circuits 72X and 72Y, and causes them to store the outputs of the inclinometer 5 in the X and Y directions at that time.

Next, the adder circuits 73X and 73Y calculate the difference between the outputs of the hold circuits 72X and 72Y and the outputs of the inclinometer 5 in the X direction and the Y direction, respectively, to calculate the difference from the time when the reset switch 6 is activated. The signal components of the inclination angle of the hand piece 1A, that is, the declination angle between the axis of the grinder 2 and the axis ZZ of the abutment tooth ST in the X and Y directions are output.

Therefore, at the time of starting cutting of the abutment tooth ST,
By simply operating the reset switch 6, the declination angle between the axis of the grinder 2 and the axis Z--Z of the abutment tooth ST can be constantly obtained with high precision.

The filter circuits 74X and 74Y are each
The outputs of the adder circuits 73X and 73Y, the declination signals in the X and Y directions between the axis of the grinder 2 and the axis Z-Z of the abutment tooth ST, are filtered to remove high frequency components caused by external vibrations, etc. In addition to obtaining a declination signal, an appropriate delay time is provided for alarm detection by the alarm circuit 76. Both filter circuits 74X,
The time constant setting circuit 75 of 74Y is the filter circuit 7
This circuit sets the filter time constants of 4X and 74Y to desired values, and is used to select 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.
An alarm is output when the declination angle between ST and axis Z-Z exceeds a predetermined alarm level, and either filter circuit 74X or 74Y exceeds the level set by alarm level setting circuit 77. Outputs a warning if By allowing the alarm level setting circuit 77 to freely set the alarm level, for example, during training for abutment tooth formation, the alarm level can be selected according to the skill of each trainee, and the training effect can be improved. can be increased.

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 .

The display devices 78X and 78Y display the outputs of the filter circuits 74X and 74Y, respectively, that is, the X-direction component and the Y-direction component of the declination angle between the axis of the grinder 2 and the axis Z--Z of the abutment tooth ST. . The display method is not particularly limited, but for example, numerical values,
Display with LED, bar graph, meter, etc. By using this indicator, for example, the deviation angle between the axis of the grinder 2 and the axis of the abutment tooth ST during training can be determined.
The instructor can constantly monitor the system, increasing the effectiveness of teaching.

Note that the display circuits 78X and 78Y display the declination angle between the axis of the grinder 2 and the axis of the abutment tooth ST.
The outputs of the adder circuits 73X and 73Y may be directly used for display without going through the filter circuits 74X and 74Y, or the outputs of the adder circuits 73X and 73Y
The output may be displayed through a filter circuit other than the filter circuits 74X and 74Y.

〔Effect of the invention〕

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

(1) Just by operating the reset switch at the start of cutting the abutment tooth, the accurate declination angle between the axis of the grinder and the axis of the abutment tooth can be obtained, making it possible to accurately level a conventional inclinometer. This eliminates the need for additional operations, greatly improving operability.

(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.

(4) By providing a display that displays the declination angle between the axis of the grinder and the axis of the abutment tooth, the instructor can constantly monitor the work status of the trainee during training for abutment tooth formation.

[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, 5 is a posture detector, 6 is a reset switch, 7 is a control circuit, 72X, 72Y are hold circuits, 73X, 73Y are adder circuits, 74
X and 74Y are filter circuits, 75 is a time constant setting circuit, 76 is an alarm circuit, 77 is an alarm level setting circuit, 78X and 78Y are indicators, and ST is an abutment tooth.

Claims (1)

[Scope of Claims] 1. A dental parallelizer in which a posture detector that outputs a signal proportional to the inclination angle of a handpiece having a grinder of an abutment tooth cutter is detachably attached so as to be freely tiltable. A reset switch is provided and a control circuit is provided, and the output of the attitude detector at the time when the reset switch is activated is stored in a hold circuit of the control circuit,
By taking the difference between the output of the attitude detector during the subsequent tooth cutting operation and the memorized output in the adding circuit of the control circuit, the declination signal of the handpiece from the time when the reset switch is activated is determined. The alarm circuit of the control circuit detects whether the declination signal of the handpiece from the time when the reset switch is activated exceeds a predetermined level, and the declination signal is calculated and output. A dental parallelizer characterized in that an alarm is issued when a predetermined level is exceeded. 2. The dental parallelizer according to claim 1, wherein the drive source for the grinder is stopped when the deviation angle signal exceeds a predetermined level. 3 The declination signal from the time when the reset switch is activated is passed through a filter circuit to provide an appropriate delay in alarm detection, and the time constant of the filter circuit can be set arbitrarily to improve the alarm detection response. The dental parallelizer according to claim 1, characterized in that the 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 declination signal from the time when the reset switch is activated is displayed on a display.