Apparatus and method for measuring the moisture level within enamel dentine or tooth tissue
First Claim
1. An apparatus for measuring the moisture level within enamel, dentine or tooth tissues of a test sample, comprising:
- a probe having two electrodes arranged such that they both contact the enamel, dentine or tooth tissues of the test sample;
an electrical power source connected between the two electrodes;
a sensor for sensing the voltage or current produced by said power source across or through the test sample; and
a signal processor responsive to said measured voltage and/or current to calculate a value indicative of said moisture level within said enamel, dentine or tooth tissues, wherein the two electrodes are arranged coaxially with in insulator layer separating them and a diameter of a tip of said probe is less than 5 mm.
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Abstract
A probe comprising two spaced electrodes is provided between which electrical resistance through enamel, dentine or tooth tissue is measured. The electrodes comprise inner and outer coaxial electrodes spaced by an insulating layer. The diameter of the probe is preferably 1 mm. The tip of the probe may be shaped to match the surface being measured. The signal from the probe is A to D converted for analysis. The rate of change of resistance gives a measure of the rate of change of moisture level (porosity). The porosity is related to tooth sensitivity and so the system can provide an objective measurement of tooth sensitivity.
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Citations
25 Claims
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1. An apparatus for measuring the moisture level within enamel, dentine or tooth tissues of a test sample, comprising:
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a probe having two electrodes arranged such that they both contact the enamel, dentine or tooth tissues of the test sample;
an electrical power source connected between the two electrodes;
a sensor for sensing the voltage or current produced by said power source across or through the test sample; and
a signal processor responsive to said measured voltage and/or current to calculate a value indicative of said moisture level within said enamel, dentine or tooth tissues, wherein the two electrodes are arranged coaxially with in insulator layer separating them and a diameter of a tip of said probe is less than 5 mm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of measuring the moisture level of enamel, dentine or tooth tissues comprising the steps of:
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removing excess surface saliva from an area to be tested of the enamel, dentine or tooth tissues;
contacting said test area with a probe having two electrodes;
connecting an electrical power source between the electrodes;
measuring the current or voltage produced by said electrical power source through or across said test area;
calculating a value indicative of the moisture level of said test area from said measured values, wherein the two electrodes are arranged coaxially with an insulator layer separating them and the diameter of the tip of said probe is less than 5 mm. - View Dependent Claims (21, 22, 23, 24, 25)
converting the analogue signals to digital signals prior to measuring them.
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23. A method according to claim 20 further comprising the step of:
comparing the measured values with calibration values.
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24. A method according to claim 20 wherein the steps are repeatedly performed over a period of time.
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25. A method according to claim 24, further comprising the steps of:
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measuring the rate of change of moisture level of the test area over time;
determining the sensitivity of the test area from said rate of change or moisture level.
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Specification