For many years we have known that reusing a dental handpiece without autoclaving it can put patients at risk. The studies surrounding this issue have repeatedly shown that both high speed and low speed hand pieces that are not autoclaved can be a source of cross contamination.1,2 In one study using a low-speed air-driven handpiece used with prophy angles, the investigators assessed contamination inside the nosecone, motor, and prophy angles. A dental handpiece is a precision-built mechanicaldevice designed for use with rotary instruments, suchas burs, stones, wheels, and discs, used in dentaltreatment. Handpieces may be air driven, electric, orcompressed gas (for surgical handpieces). Surgicalhandpieces are discussed in Dental Technician,Volume 2, Chapter 5, “Oral Surgery Assistance.”
Put on clean gloves and remove the handpiece from the autoclave when the cycle is over. Run lubrication through the handpiece if it is scheduled to be lubricated. If you are lubricating the handpiece, run it on the air supply line to remove excess lubrication, and wipe with a germicidal wipe afterward.
Lubricate the handpiece. Use the proper lubricating tip to spray oil into the drive airline. Spray until oil comes out of the handpiece head. This ensures that lubricant has penetrated to the bearings. Even if the lubricant is delivered incorrectly, oil coming from the head indicates it has reached the bearings. Note: Using spray oil has become less popular because of perceived mess and waste. Many offices are moving to dropper-style applicators to oil the handpiece. Use of a dropper makes the next step — running out the excess oil — critical because the droplets will not be delivered to the bearings without being propelled by pressurized air. If you prefer a dropper, apply two to three good size drops to the drive air hole and immediately run the handpiece.
Motors, especially vane rotors, do not require much oil. Dental motors and attachments require higher viscosity oil than a high-speed spray. One or two drops of oil in the drive airline are all that is necessary. Run the motor to distribute the oil. Also apply some oil as a preventive measure to forward/reverse valves, shift rings, and sheath attachment points. Wipe away excess oil with a paper towel.
The part that is really important for all dental health-care professionals (DHCP) to remember is that these studies show that even with the use of a simple prophy angle, the internal unit of the handpiece became contaminated, and cross contamination became a strong possibility.
The risk of infection with and appropriate sterilization procedures for machines with internal tubings is a controversial matter. While there are publications linking internal tubings to infections,3-5 I am told there is also one non-peer-reviewed company document to refute this. Having experienced infections tracked to such internal tubings by modern epidemiological and microbiological techniques, I have tried to convince one reputed manufacturer of such machines to at least disseminate newly revised cleaning instructions for their product to their numerous installations. Implementation was promised 2 years ago. However, despite the fact that the revised protocol was developed by their own engineers they have, to date, neither committed to its dissemination nor demonstrated to all their customers. They have not even done this for all customers with service contracts. Perhaps they have too many installations to cater to or are overly worried about the possible fall out, but I do think industry responsibility should go beyond the sale of their machines. Indeed I get this distinct feeling of déjà vu: we experienced a similar lack of responsibility and follow-up with contaminated irrigating solutions used in cataract surgery.6 Internal tubings may be more controversial and may not merit product recall, they certainly merit post-sales education of safety measures developed by their own engineers.