Dental bearings come in a lot of forms, level of quality and prices. Bearings for dental tools are usually created with an accent on precision, high speed and reliability. Because they are a lot of different types of dental bearings, we decided to make a long story short and drive some light over the benefits of different types of dental bearings.
Basically, there are two general types of dental bearings depending on the type of work that the dental tools are created for: radial bearings and angular bearings. Both of them are used in modern dental equipment and have their own purpose, thus advantages.
The first type (radial bearings) includes rolling-element bearings that use balls to maintain the separation between the bearing races, their purpose being to reduce rotational friction and support radial and axial loads. It’s designed for working in deep grooves and for angled dental surfaces. Radial bearings have an inner ring, an outer ring, a series of balls and typically a cage to contain the balls.
The second type of dental bearings is the angular bearing. Such dental bearings are used for side or thrust loads. Thrust bearings use balls, rollers or needles. In addition to these working surfaces they also typically have a ring and a seating surface. Here, the material plays an important role – using ceramic bearings in your dental handpiece will allow it to last up to 30% longer, compared to standard steel bearings.
Depending on their speed of rotation ball bearings used in a number of dental instruments can be separated into two groups. The speed of rotation is measured with RPM (Rotations per minute) – a measure that describes how many turns around a fixed axis are made per minute:
- High speed dental bearings – with RMP from 100,000 to 400,000;
- Low speed dental bearings – with RPM from 25,000 to 100,000.
Because the technical operation of a dental rotor is highly dependent on the choice of its details, mostly dental rotors/cartridges are assembled with the first type – high speed dental bearings.
There are three aspects that influence the selection of the dental bearings:
- the configuration,
- the materials used,
- the manufacturer.
The configuration of dental bearings
Essentially, ball bearings are available with angular contact configuration and radial contact configuration. The difference between the angular and radial bearings is in the retainer type. The last one defines the support of load from axial and radial direction.
Radial ball bearings are based on a crown retainer and are more convenient to use, as they can be installed and axially loaded from either side.
Angular contact ball bearings include a full retainer and can only be axially loaded from one side. However, they have another advantage – they better support “combined loads”, in both the radial and axial directions. Angular contact ball bearings perform better at higher speeds. They also have a different life-span, on average they operate longer than radial bearings.
Materials of the dental bearings? Ceramic versus steel.
There are ceramic ball bearings which include hardened steel rings and silicon nitride (ceramic) balls, and steel ball bearings with steel rings and steel balls.
The clear advantage of using a hybrid ceramic ball bearing is that usually it runs cooler and extends the life of the tool. Due to the non-porous structure of the ceramic ball bearings, they are virtually frictionless and, thus, they have an increased speed rating.
Moreover, a ceramic ball has a different weight – it’s approximately 60% lighter than a steel ball of the same size. On the grounds of that, the lighter ceramic ball-set generates less centrifugal force when operating at super-high speeds, as a result, the wear on the raceway of the outer ring is minimized. Surface wear is supplementarily reduced because ceramic and steel are such unsimilar substances.
Even though it might seem surprising, ceramic balls are actually harder than heat-treated steel balls, so it’s less likely that external contaminants or bearing wear debris will damage them and cause the bearing to fail in the end. The dental equipment that includes such dental bearings is not only lighter, but also quieter. In addition, a hybrid ceramic bearing works better than an all-steel ball bearing with less lubricant.
In conclusion, the benefits of ceramic angular contact bearings are:
- High stiffness
- Longer life
- Increased speed rating
- Reduced weight
- Longer lubricant service life
- Lower operating temperatures
- Zero impact on assembly processes
- Lower noise level (up to 25%)
When you decide to buy dental rotors, dental turbines or dental bearings, you have to pay attention to the manufacturer. Many providers of dental bearings are actually offering bearings of unknown origin, which might be a serious problem, even if you manage to reduce your spendings buying them. Because these bearings mostly come from questionable productions or are produced for low standard markets, the might wear out faster or encourage accidents with their lack of compatibility with the dental equipment. Dental rotors offers you rotors assembled with top quality ball bearings, which are made by verified producers, so you could use them with trust for a long time and come back for more dental spare parts.