Abstract A method for measuring the depth of a root canal in a tooth including: (1) forming an opening in the tooth crown, (2) placing a disc-shaped electrode on mucosa adjacent the submerged tooth root, (3) inserting a probe electrode in the form of an endodontic file through the opening into the root canal, (4) measuring the capacitance across the electrodes, (5) continuing to further insert the probe electrode until the capacitance substantially increases, and (6) measuring the depth of penetration at the point the capacitance substantially increases to locate the apical foramen. The device for carrying out the method includes an oscillator set at 10 KHz and a capacitance bridge circuit connected to the oscillator. The electrodes form one arm of the bridge circuit, and a known capacitance of about 0.08 Mu f forms another arm thereof. The output of the bridge circuit is fed into a null detector so that an increase appearing on a null meter is seen when the probe electrode reaches the apical foramen.
A method of measuring the depth of a root canal in a tooth comprising: a. forming an opening in the tooth crown, b. placing an electrode on mucosa adjacent the submerged tooth root, c. inserting a probe electrode through said opening into the root canal, d. connecting an oscillator to a capacitance bridge circuit and connecting said electrodes as one arm of said bridge circuit, e. measuring the capacitance across said electrodes, f. continuing of further insert said probe electrode, g. determining the point wherein the capacitance approximately doubles to locate the apical foramen, h. removing said probe electrode and measuring its depth of penetration at the point the capacitance approximately doubles.
Claim 2
Independent Claim
112 words
A method of measuring the depth of a root canal in a tooth comprising: a. forming an opening in the tooth crown, b. placing an electrode on mucosa adjacent the submerged tooth root, c. inserting a probe electrode through said opening into the root canal, d. connecting an oscillator to a capacitance bridge circuit and connecting said electrodes as one arm of said bridge circuit, e. measuring the capacitance across said electrodes, f. continuing of further insert said probe electrode, g. determining the point wherein the capacitance approximately doubles to locate the apical foramen, h. removing said probe electrode and measuring its depth of penetration at the point the capacitance approximately doubles.
Claim 3
Dependent Claim
19 words
A method as defined in claim 1 including connecting said bridge circuit to a tuned amplifier and null detector.
Claim 4
Dependent Claim
24 words
A method as defined in claim 1 including setting said oscillator at 10HKz and placing a potential difference of 1 volt across said electrodes.
Claim 5
Dependent Claim
24 words
The method of claim 1 including the step of inserting a saline solution into said root canal prior to insertion of said probe electrode.
Claim 6
Dependent Claim
23 words
A method as defined in claim 1 including placing A known capacitance of about 0.03-0.15 microfarads in one arm of said bridge circuit.