阅读说明：本技术 一种确定牙齿上阻抗的设备和方法 (Apparatus and method for determining impedance on teeth ) 是由 迈克尔·根特 马蒂亚斯·威拉莫夫斯基 于 2018-11-09 设计创作，主要内容包括：本发明涉及一种确定牙齿上的阻抗(交流电阻)的设备和方法。通过在给定电流强度下测量电压或通过在给定电压下测量电流强度来确定阻抗。确定牙齿上的阻抗可用于诊断龋齿。(The present invention relates to an apparatus and method for determining the impedance (ac resistance) on a tooth. The impedance is determined by measuring the voltage at a given current level or by measuring the current level at a given voltage. Determining the impedance on the tooth can be used to diagnose dental caries.)

1. An apparatus (1) for determining impedance on a tooth, comprising

-a measuring unit (2) for generating an alternating voltage,

-a reference electrode (4) connected to the measuring cell (2),

-a measuring electrode (5) connected to the measuring unit (2),

-a compensation electrode (6) connected to the measuring unit (2),

wherein the measuring electrode (5) and the reference electrode (4) are arranged relative to each other such that an alternating current can flow from between the measuring electrode (5) and the reference electrode (4) on the tooth to be examined in a first position;

and wherein the measuring unit (2) can determine the impedance from the resulting current intensity;

the measuring electrode (5) and the compensation electrode (6) are at the same potential;

and applying an insulating layer (7) between the measuring electrode (5) and the compensation electrode (6) to insulate the two electrodes from each other; the measuring unit (2) comprises an evaluation unit which captures the impedance changes when determining at least two positions of the tooth to be examined;

the measuring unit (2) is connectable to an output device for outputting an impedance and/or an impedance change;

the device (1) comprises a handle (3) for holding the measuring unit (2) during the determination so that the device (1) can be placed on the tooth to be examined during the determination,

characterized in that the device (1) comprises an insulating gel (9) arranged to insulate the measuring electrode (5) from saliva in the oral cavity.

2. Device (1) for determining the impedance on a tooth according to claim 1, characterized in that the resistivity of the insulating gel (9) is ρ >500 Ω -m.

3. Device (1) for determining the impedance on a tooth according to claim 2, characterized in that the insulating gel (9) comprises agar and distilled water.

4. Device (1) for determining the impedance on a tooth according to claim 1 or 2, characterized in that the insulating gel (9) contains a dye, preferably a blue dye.

5. Device (1) for determining the impedance on a tooth according to any one of the preceding claims, characterized in that the output means of the measurement unit (2) comprise an optical and/or acoustic and/or tactile indication.

6. Device (1) for determining the impedance on a tooth according to any one of the preceding claims, characterized in that the reference electrode (4), the measuring electrode (5) and/or the compensation electrode (6) consist of a metal such as titanium, silver or iron, or of a metal alloy, or preferably of stainless steel or carbon.

7. Device (1) for determining the impedance on a tooth according to one of the preceding claims, characterized in that the measuring electrode (5) and the compensation electrode (6) are implemented as planar membranes.

8. Device (1) for determining the impedance on a tooth according to any one of the preceding claims, characterized in that the insulating layer (7) consists for example of a plastic such as polycarbonate or polyethylene.

9. Device (1) for determining the impedance on a tooth according to any one of the preceding claims, characterized in that the handle (3) has a surface made of an electrically insulating material, for example a plastic such as polycarbonate or polyethylene.

10. Device (1) for determining the impedance on a tooth according to one of the preceding claims, characterized in that the measuring electrode (5) is mounted elastically using an elastic element (8) and is thus arranged axially displaceable with respect to the compensation electrode 6.

11. Device (1) for determining the impedance on a tooth according to any one of the preceding claims, characterized in that the measuring electrode (5) has a tapered tip.

12. Device (1) for determining the impedance on a tooth according to any one of the preceding claims, characterized in that the reference electrode (4) is embodied as a bent stainless steel wire.

13. Device (1) for determining the impedance on a tooth according to one of the preceding claims, characterized in that the measuring unit (2) is integrated in the handle (3) such that only one common housing is required.

14. A method of determining impedance on a tooth using a device (1) according to any one of the preceding claims, comprising the steps of:

1. the saliva on the tooth to be examined is removed,

2. applying an insulating gel (9) on said tooth to be examined,

3. placing the measuring electrode (5) in a first position on the tooth to be examined, the measuring electrode (5) being directly incident on the tooth,

4. placing the reference electrode (4) at any location in the oral cavity,

5. applying an alternating voltage between the measuring electrode (5) and the reference electrode (4) using the measuring cell (2),

6. the resultant current is measured and the resultant current,

7. determining an impedance from the alternating voltage and the resultant current,

8. repeating steps 3 to 7 at least one further position on the tooth to be examined,

9. at least two impedances are compared, whether or not the captured impedance changes during the process.

15. Use of a device (1) according to any one of claims 1 to 13 for determining the impedance on a tooth.

Background

The following devices or methods may be used to diagnose dental caries:

visual diagnosis: the cleaned and dried teeth were examined for discoloration and cavitation (collapse of hard tissue of the teeth) by observation and under good lighting conditions using a mouth mirror.

Tactile detection: the cleaned and dried teeth were probed using a dental probe.

Fiber transillumination (FOTI, transillumination): a cold light probe is used to transilluminate the hard tooth tissue. Here, different properties of healthy teeth and carious hard tooth tissue are used when diffracted light is used. The carious substance is identified as a dark shadow due to the loss of light intensity. This makes it possible to diagnose dental caries in particular well.

X-ray film inspection: x-ray film examination using conventional or digital techniques is performed by biting. This allows a good diagnosis of enamel caries on the adjacent surfaces, which refers to the tooth surfaces, especially where a row of teeth is in contact.

Laser-assisted caries diagnosis (laser fluorescence measurement): light of the laser fluorescent device at a wavelength of 650nm is absorbed by organic and inorganic substances. The laser fluorescence device consists of at least one light source and an optical unit, the dimensions of which are generally adapted to the design. Since the laser used excites fluorescence from caries lesions in the hard substance of the teeth, it can be concluded that caries is present if fluorescence is present. The method is particularly suitable for diagnosing caries.

Determination of the ac resistance on the tooth (impedance measurement): in this way the impedance of the dental hard substance is determined using a suitable measuring device. In the case of dental caries, the electrical conductivity and therefore the impedance are significantly increased compared to healthy dental hard substances. Since the impedance of enamel is significantly higher than dentin, this method is particularly useful for diagnosing carious lesions of enamel. Impedance measurement is a very suitable method if the caries has not resulted in cavitation and is therefore not identifiable either visually or by a tactile probe.

An alternating current operated device is used to determine the impedance. These measuring devices comprise at least a reference electrode, a measuring electrode and a measuring cell. The reference electrode is placed anywhere in the mouth. The measuring electrodes are used for sensing the tooth to be examined. The impedance drops once the measuring electrode comes into contact with the caries change. This change in impedance is recorded by the measuring unit and communicated to the examiner, for example by means of an acoustic warning signal or an optical display, and the indicator of the ac resistance measuring device can be used as an optical display and also as a light-emitting display, the color of which changes from green to red, for example, when the resistance changes. The light emitting display may be, for example, an LED display with diodes of different colors.

When the tooth surface to be inspected is sensed using the measuring electrode, cracks and small pits of the occlusal surface are mainly inspected. If the measuring electrode contacts the carious point, the impedance will decrease because the enamel of the tooth is porous at the carious point.