(77 days)
Measurement of the length of the root canal for the purpose of performing root canals and related dental procedures.
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.
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.
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