ROOT APEX LOCATOR by TOEI ELECTRIC CO., LTD.

The subject device is a lightweight, fully-automatic, battery-operated device that allows a dentist or oral surgeon to locate a patient's anatomical root canal apex and obtain accurate root canal length measurements. The device allows the relative position of a dental file and the apex to be determined electrically. Using a standard dental file inserted into the root canal as an electrode, the device emits very small electrical currents having frequencies of 500 Hz and 2000 Hz. The impedance between the file and mouth is measured at each of these frequencies, and compared, with a readout of the relative proximity to the apex appearing on a stabilized meter. The use of two frequencies minimizes errors introduced by blood or other conducting medicinal fluids in the root canal.

The subject device consists of a main body, incorporating the panel meter, a probe cord and reel, a canal instrument holder, a mouth angle clip, a saliva ejector clip, and batteries. The device operates on four AAA 1.5 v. batteries.

AI/ML Overview

Here's an analysis of the provided text, focusing on acceptance criteria and the study proving the device meets them:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state formal "acceptance criteria" with numerical thresholds. Instead, the performance evaluation aims to demonstrate "no significant difference" between the subject device and the predicate device, and "no significant statistical differences" between the subject device and Ingle's method.

Given this, the table below reflects what can be inferred as the implicit performance target based on the study's conclusions.

Acceptance Criteria (Inferred)	Reported Device Performance
No significant difference in accuracy compared to predicate device (Root ZX) in obtaining tooth length across various media.	Met: "The tests showed no significant difference between the subject device and the predicate in obtaining tooth length in each of the three media tested [dry, saline, 2.5% sodium hypochlorite solutions]."
No significant statistical differences in readings compared to Ingle's calculated length method.	Met: "no significant statistical differences were found between readings taken by the subject device and Ingle's method."

2. Sample Size Used for the Test Set and Data Provenance

Sample Size: The document states that "sample extracted teeth having both straight and curved canals" were used, but it does not specify the exact number of teeth used in the test set.
Data Provenance: The study was an "in vitro testing model," meaning it was conducted in a laboratory setting using extracted teeth, not on live human subjects. The country of origin of the data is implicitly Japan, as the submitter, Toei Electric Co., Ltd., is based in Japan. The study is described as a "Non-Clinical Data" study.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

The document does not specify the number of experts used or their qualifications for establishing ground truth. The ground truth was established through "measurements obtained physically, radiographically, and using an Ingle's calculated length." This suggests a combination of objective physical measurements and a recognized clinical method (Ingle's).

4. Adjudication Method for the Test Set

The document does not describe an adjudication method involving multiple readers/experts for the test set. The ground truth was established through specific measurement techniques (physical, radiographic, Ingle's method).

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance

This was not a Multi-Reader Multi-Case (MRMC) comparative effectiveness study. The device is an electronic root canal length measurement device, not an AI-assisted diagnostic tool that would typically involve human readers interpreting images. Therefore, the concept of human reader improvement with/without AI assistance does not apply here.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Yes, this was effectively a standalone performance study of the device. The "accuracy of the subject device was confirmed using an in vitro testing model" by comparing its output directly against established ground truth methods. It measures an objective physical characteristic (length) and does not involve human interpretation as part of its primary function during this test.

7. The Type of Ground Truth Used

The ground truth used was a combination of:

Physical measurements: Direct measurements on the extracted teeth.
Radiographic measurements: Measurements derived from X-ray images.
Ingle's calculated length: A well-known clinical method for determining root canal length.

8. The Sample Size for the Training Set

The document does not mention a training set. This type of device, an electronic measurement tool, typically does not involve machine learning or AI models that require a separate training set. Its functionality is based on established electrical impedance principles.

9. How the Ground Truth for the Training Set Was Established

As no training set is mentioned or implied for this device, information on how its ground truth was established is not applicable/provided.

Summary

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SEP 1 1 1997

K972407

Summary of Safety and Effectiveness - 510(k) Summary I.

Submitter Information:

Toei Electric Co., Ltd. 771, Shimosakunobe Takatsu-ku, Kawasaki Kanagawa-ken 213 Japan (81)(44)877-5410

Robert P. Reznick, Esq. Contact Person: Hughes Hubbard & Reed LLP 1300 I Street, N.W. Washington, D.C. 20005 (202) 408-3740

2. Device Information:

Root canal length measurement device. This device is not classified.

Predicate Device:

Root ZX, K953867, K921979

Device Description:

The subject device is intended to be used to measure the length of the root canal for the purpose of performing root canals and related dental procedures.

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Device Characteristics	Subject Device	Root ZX
Power source	4 AAA batteries	5 AA batteries
Electric current	Less than 10 µA	Less than 10 µA
Method of calculating locationof root canal apex	Comparison of impedance at2 frequencies	Comparison of impedance at2 frequencies
Frequencies used forcomparison	500 Hz & 2,000 Hz	400 Hz & 8,000 Hz
Number of cycles used formeasurement	2	2
Display	Analog	Liquid crystal
Adjustment beforemeasurement	Unnecessary	Unnecessary
Measuring voltage	50 mV	80 mV
Audio location indicator	Yes	Yes
Weight	Approx. 280g	Approx. 550g
Use with standard dental files	Yes	Yes
Automatic on/off switch	Yes	No

5. Comparison With Predicate Device:

The Subject device and the Root ZX utilize the same method of calculating root canal lengths by comparing electrical impedances at two frequencies and are substantially equivalent in all particulars.

6. Non-Clinical Data Necessary To A Finding Of Substantial Equivalence:

The accuracy of the subject device was confirmed using an in vitro testing model against measurements obtained physically, radiographically, and using an Ingle's calculated length. Measurements were taken in sample extracted teeth having both straight and curved canals. Measurements were also made under conditions in which the teeth were dry and in which they were in the presence of saline and 2.5% sodium hypochlorite solutions. The tests showed no significant difference between the subject device and the predicate in obtaining tooth length in each of the three media tested. Moreover, no significant statistical differences were found between readings taken by the subject device and Ingle's method.

Submitted June 26, 1997

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/2/Picture/1 description: The image is a black and white logo for the Department of Health & Human Services - USA. The logo consists of a circular border with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized symbol that resembles an abstract human figure or a bird in flight, composed of three curved lines.

Public Health Service

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

SEP 1 1 1997

Mr. Robert P. Reznick TOEI Electric Company, LTD C/O Hughes, Hubbard & Reed LLP 1300 I Street, N.W. 20005 Washington, DC

K972407 Re : Root Apex Locator Trade Name: Regulatory Class: Unclassified Product Code: LQY June 26, 1997 Dated: Received: June 26, 1997

Dear Mr. Reznick:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions The general controls provisions of the Act of the Act. include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Requlations, Title 21, Parts 800 to 895. ਸੋ substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory In addition, FDA may publish further announcements action. concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531

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Page 2 - Mr. Reznick

through 542 of the Act for devices under the Electronic enzough Siz on Control provisions, or other Federal laws or requlations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4618. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other qeneral information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

Alatoust

Director Division of Dental, Infection Control and General Hospital Devices Office of Device Evaluation Center for Devices and Radioloqical Health

Enclosure

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Page__________________________________________________________________________________________________________________________________________________________________________

510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________

Root apex locator Device Name:__

Indications For Use:

Measurement of the length of the root canal for the purpose of performing root canals and related dental procedures.

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

	Susan Runner
(Division Sign-Off)
Division of Dental, Infection Control, and General Hospital Devices
510(k) Number	K972407

Prescription Use (Per 21 CFR 801.109)	OR	Over-The-Counter Use (Optional Format 1-2-96)
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Regulation Number and Section

N/A