Letter to Electric Dental Handpiece Manufacturers Regarding Reports of Overheating and Patient Burns

NOTICE of Safety Concern for Electric Dental Handpieces and Accessories

Certified Mail – Return Receipt Requested

August 20, 2010
Dear __________:
On December 12, 2007, the U.S. Food and Drug Administration (FDA) posted a public health notification alerting the public that the Agency had received reports of patient burns from electric dental handpieces. Since this communication, the FDA has received numerous additional reports, some detailing serious patient injuries, including third degree burns.
We are requesting your assistance in correcting the problems associated with patients being severely burned from overheating electric dental handpieces during dental procedures. We are also reminding you of your responsibilities as a manufacturer to comply with FDA requirements for medical devices including requirements under the Medical Device Reporting (MDR) rule, 21 CFR Part 803, to address this public health issue.

Background Information

Patients have been severely burned when electric dental handpieces have overheated during dental procedures. Some patients had third degree burns which required reconstructive surgery. Burns may not be apparent to the operator or the patient until after the tissue damage has occurred, because the anesthetized patient cannot feel the tissue burning and the handpiece housing insulates the operator from the heated attachment. Although the reported burns have occurred during cutting of tooth and bone, tooth extraction and other dental surgical procedures, overheating could occur during any dental procedure.
With high and low speed air-driven handpieces, sluggish handpiece performance will alert the dental practitioner to maintenance issues such as a dull bur or worn or clogged gears or bearings. A poorly maintained electric handpiece does not provide a similar warning that maintenance is needed. Instead, if an electric handpiece is worn, damaged or clogged, the electric motor sends increased power to the handpiece head or attachment in order to maintain handpiece performance. This increased power can rapidly generate heat at the head of the handpiece attachment. Because the heat buildup is so rapid, and is efficiently conducted through the metal handpiece, a burned patient may be the first indication of handpiece problems that the practitioner receives.

Factors That May Contribute to Adverse Events

1. The labeling may not establish or adequately communicate a proper maintenance schedule;
2. Users may not be aware that improperly maintained, damaged or worn devices have the potential to overheat without warning;
3. Users may continue to use these products even after the device has overheated because they may not easily perceive it is approaching dangerous temperatures;
4. Prescribed start up checks designed to alert the user of device failure by overheating may not realistically recreate the operating parameters that may cause overheating.

Actions to Address the Potential for Burns from Electric Dental Handpieces

1. Records Review--Review your complaint records to identify reports and root causes of an overheating hazard. Review your adverse event files to evaluate whether your device is dangerous to health if used as suggested in the labeling. Using this information, verify that your risk management plan adequately addresses burn hazards.
2. Human Factors--Ascertain whether dental professionals’ understanding of your labeling and the feasibility of performing the required maintenance of your product is adequately understood. Refer to the Guidance for Industry - Medical Device Use-Safety: Incorporating Human Factors Engineering into Risk Management issued July 18, 2000, for information about human factors and medical devices .
3. Risk Mitigation--Consider the risk mitigation steps below (from most desirable to least desirable).
   1. Eliminate overheating through design modification.
   2. Protect or guard against overheating through design modification such as an overheating alarm.
   3. Warn the operator about overheating through warning labels.
   4. Train and instruct operators to avoid the hazard.
   5. Modify use of the device to preclude the hazard.

In addition to the activities referenced above, the FDA continues to believe that improved product labeling and educational outreach is important. However, based on the continuing adverse event reports of patient burns, the FDA believes labeling and outreach alone cannot sufficiently mitigate the occurrence of patient burns.

Reporting to the FDA

As a manufacturer of these devices, you are responsible for compliance with the requirements of the medical device reporting (MDR) rule. These requirements include reporting to FDA deaths and serious injuries that your device may have caused or contributed to and certain device malfunctions, and establishing and maintaining adverse event files.
To ensure that relevant manufacturers receive this information, attached for your signature is an acknowledgement form. Please check all appropriate lines and return the form to acknowledge receipt of this letter and confirm your status as an electric dental handpiece and/or accessories manufacturer.
Send a copy your communication to: Mr. Gregory W. O’Connell, Acting Director, Division of Enforcement A, Office of Compliance, 10903 New Hampshire Avenue, WO66-3516, Silver Spring, Maryland, 20993.
If you have questions relating to this matter, please feel free to call Mr. O’Connell at
(301) 796-5770, or log onto our web site at www.fda.gov for general information relating to FDA medical device requirements.
Sincerely yours,
Timothy A. Ulatowski
Director
Office of Compliance
Center for Devices and Radiological Health