JUSTWO MODEL TME-601 ROOT APEX LOCATOR

• K Number: K022020
• Device Name: JUSTWO MODEL TME-601 ROOT APEX LOCATOR
• Manufacturer: TOEI ELECTRIC CO., LTD.
• Date Cleared: 2002-07-02 ( 12 days)
• Product Code: LQY
• Regulation Number: N/A
• Type: Special
• Panel: Dental
• Reference & Predicate Devices: K972407
• Predicate For: K030526 , K032743

Intended Use

Measurement of the length of the root canal for the purpose of performing root canals and related dental procedures, for use by a trained professional in general dentistry.

Device Description

The subject device is a lightweight, fully-automatic, batteryoperated 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 current 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 is an analysis of the provided text, focusing on acceptance criteria and the study details:

1. Table of Acceptance Criteria and Reported Device Performance

The provided text does not explicitly state numerical acceptance criteria for the "JUSTWO" Model TME-601 Root Apex Locator. Instead, it focuses on demonstrating substantial equivalence to a predicate device and proving its accuracy. However, we can infer the unstated acceptance criterion related to accuracy based on the study's findings.

Acceptance Criteria (Implied)	Reported Device Performance
Accuracy: No significant difference in obtaining tooth length compared to physical, radiographic, and Ingle's calculated length measurements.	Accuracy: 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). Moreover, 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

• Test Set Sample Size: The document mentions "sample extracted teeth" but does not specify the exact number of teeth or measurements used in the in vitro testing model.
• Data Provenance:
  • Country of Origin: Not explicitly stated, but the company is Japanese (Toei Electric Co., Ltd., Japan). The study itself is an in vitro test.
  • Retrospective or Prospective: The study was a prospective in vitro testing model.

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

The document does not specify the number of experts or their qualifications. The ground truth was established through physical measurements, radiographic measurements, and Ingle's calculated length. While these methods imply the involvement of skilled individuals (e.g., those performing physical measurements or reading radiographs), the text does not detail their expertise.

4. Adjudication Method for the Test Set

The document does not describe an adjudication method involving experts making decisions. The comparison was made against established measurement methods (physical, radiographic, Ingle's).

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• Was an MRMC study done? No, the document does not describe an MRMC comparative effectiveness study involving human readers. The study was an in vitro assessment of the device's accuracy.
• Effect size of human readers improve with AI vs without AI assistance: Not applicable, as no MRMC study involving human readers or AI assistance was conducted.

6. Standalone Performance (Algorithm Only without Human-in-the-Loop Performance)

Yes, a standalone study was done. The in vitro testing model assessed the device's accuracy directly by comparing its measurements to physical, radiographic, and Ingle's calculated lengths. This evaluates the algorithm's (or device's electrical measurement system's) performance without direct human intervention in the measurement process beyond initiating the device and recording results.

7. Type of Ground Truth Used

The ground truth used was a combination of:

• Physical measurements: Directly measuring the length of the extracted teeth.
• Radiographic measurements: Measurements obtained from radiographs.
• Ingle's calculated length: A standardized method for calculating working length in endodontics.

8. Sample Size for the Training Set

The document does not mention a discrete training set. The device's design and underlying electrical principles are based on established knowledge of impedance/current changes in the root canal. The "accuracy" study described serves as a validation or test set, not a training set for the device itself.

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

Not applicable, as a separate training set for a "machine learning" type algorithm is not described. The device operates based on fixed electrical principles using two frequencies (500 Hz and 2000 Hz) and comparing currents, rather than being "trained" on a dataset in the modern AI sense.

Summary

{0}------------------------------------------------

JUL - 2 2002

EXHIBIT 2 TOEI ELECTRIC CO., LTD. 771, SHIMOSAKUNOBE KANAGAWA-KEN 213 KAKATSU-KU, KAWASAKI, JAPAN Phone [phone] Fax [phone] Contact: Masahiro Fujita, President 510(k) Summary of Safety and Effectiveness

• 1. Identification of the Device: Proprietary-Trade Name: "JUSTWO" Model TME-601 Root Apex Locator Classification Name: LOY Common/Usual Name: Root Apex Locator This device has not been classified.
• 2. Equivalent legally marketed device: Toei Electric Co. Ltd "Root Apex Locator" K972407
• 3. Indications for Use (intended use) The device is for measurement of the length of the root canal for the purpose of performing root canals and related dental procedures.
• 4. Description of the Device: The subject device is a lightweight, fully-automatic, batteryoperated 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 current 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.

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.

{1}------------------------------------------------

• 5. Safety and Effectiveness, comparison to predicate device:

Device Characteristics	Subject Device (K972407)	Modified Device
Name	"Root Apex Locator"	"JUSTWO" Model TME-601Root Apex Locator (Newname for device)
Power source	4 AAA batteries	SAME
Electric current	Less than 10 μA	SAME
Method of calculating locationof root canal apex	Comparison of "impedance"at 2 frequencies (Unit actuallymeasured current, notimpedance)	Measurement of current at 2frequencies
Frequencies used forcomparison	500 Hz & 2,000 Hz	SAME
Number of cycles used formeasurement	2	SAME
Display	Analog	SAME
Adjustment beforemeasurement	Unnecessary	SAME
Measuring voltage	50 mV	SAME
Audio location indicator	Yes	SAME
Weight	Approx. 280 grams	SAME
Use with standard dental files	Yes	SAME
Automatic on/off switch	Yes	SAME

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.

{2}------------------------------------------------

Image /page/2/Picture/1 description: The image is a black and white logo for the U.S. Department of Health & Human Services. The logo features a circular design with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" arranged around the perimeter. Inside the circle is a stylized image of three human profiles facing right, with flowing lines representing hair or clothing.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

JUL = 2 2002

Toei Electric Company, Limited C/O Daniel Kamm, P.E. Regulatory Engineer Kamm & Associates P.O. Box 7007 Deerfield, Illinois 60015

Re: K022020

Trade/Device Name: JUSTWO Model TME-601 Root Apex Locator Regulation Number: Unclassified Regulation Name: Root Apex Locator Regulatory Class: Unclassified Product Code: LQY Dated: June 18, 2002 Received: June 20, 2002

Dear Mr. Kamm:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions 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 (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies.

{3}------------------------------------------------

Page 2 - Mr. Kamm

This letter will allow you to begin marketing your device as described in your Section 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 21 CFR Part 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at [phone]. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at [phone]. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number [phone] or [phone] or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely,

Timothy A. Ulatowski Director Division of Anesthesiology, General Hospital, Infection Control and Dental Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

{4}------------------------------------------------

k) Indications for Use

510(k) Number__KO22 O20

청

Device Name: "JUSTWO" Model TME-601 Root Apex Locator.

Indications for Use: Measurement of the length of the root canal for the purpose of performing root canals and related dental procedures, for use by a trained professional in general dentistry.

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use	✓
	OR
Over the Counter Use	(Per 21 CFR 801.109)

(Division Sign-Off)

Division of Dental

(Division Sign-Off)
Division of Dental, Infection Control,
and General Hospital Devices
510(k) Number K022080

Regulation Number and Section

N/A