A Guide to Dental Handpiece Gear Ratios

A Guide to Dental Handpiece Gear Ratios For an ideal dental healthcare environment, it is paramount that the right equipment is available and that this equipment has the right properties and features. These properties indicate the exact operation for which the dental equipment can be used and they also mark the exact specifications of the device. The specifications indicate the exact operations and procedures in which the dental equipment can be used. This makes the practice of dentistry easier for dental practitioners in dental healthcare environments.

Dental Handpiece Gear Ratios

One of the most important features is the gear ratio. The dental practice uses dental drills or handpieces to perform several procedures such as polishing fillings, removing dental decay, changing prostheses as well as performing cosmetic dentistry. The dental handpieces are designed to consist of internal mechanical components.

These components start a rotational force which provides power to the cutting instrument. This instrument is usually a dental burr. In order to power a high-speed handpiece, gears are needed to increase the speed of an electric motor.

The gear ratio is imprinted on electric dental handpieces to decide the procedures to be performed. The format in which the gear ratio is expressed is X: Y. This ratio is an important parameter to judge the capabilities of devices.

It helps to determine in which dental procedures can the device be used. Different ratios signify different kinds of properties.

A high-speed handpiece has a ratio of 1:5. Contrarily, the slow speed devices have a ratio of 1:1.

Further, to perform extremely slow dental operations, some companies also provide handpieces with gear ratios as low as that of 10:1 or 16:1.

During the dental procedure, the gear ratio helps to change the rpm of the motor to the required rpm. For example – the maximum rpm that can be produced using a micromotor is 40000-45000. However, very high rpm is required during crown cutting.

Therefore, the gear ratio for electrical handpieces is 1:5 and the handpiece comes with a red colour ring. Also, the 1:5 gear can increase the rpm of the motor by 5 times.

Hence, the effective rpm will be 200000. With increasing speed, the handpiece which is meant for speed reduction will decrease the speed according to the gear ratio.

Dental Handpieces example:

An M4 handpiece with 10:1 reduction will decrease the micromotor rpm 35000 by 10 times. Hence, the effective rpm to the file will be only 3500. A 1:1 handpiece always delivers the same rpm of the motor to the file. Though in endomotors that provide the option of gear selection like #Xsmart, #Endomate etc, confusion might arise.

The usual dental procedures such as crown preparation, cavity preparation, and sectioning the existing fixed prosthetics need a handpiece with a gear ratio of 1:5. These procedures require high-speed handpieces and hence use such pieces of equipment. These handpieces have the standard friction-grip burs or push-button bur chucks or diamonds, depending on the manufacturing and design process.

The slow-speed handpieces have a ratio of 1:1. The handpieces which have this ratio indicated are used for several purposes. These include dental procedures such as removing caries, adjustment of ceramics and preparation refinement. The slow-speed heads come in different designs depending on the manufacturer. They are available in either a friction-grip or a latch-grip. The friction-grip slow-speed head has an advantage.

It is that any bur which can be used while working in a high-speed dental healthcare environment can also be alternatively used in a slow speed dental healthcare environment. This makes them extremely useful and cost-effective for dental practitioners. Further, friction-grip burs usually come at less than half the retail cost of latch grip burs and diamonds are only offered in friction-grip applications.

Given the importance of how the gear ratio helps to ascertain where and how the dental devices have to be used, it is an extremely important parameter for the practice of dentistry.