(12 days)
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.
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.
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.
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