ISO 20127 Dentistry - Fusisal Characteristics of Reliable Instruments

The standard “ISO 20127 Dentistry - Fusisal properties of reliable instruments” developed by the International Organization for Standardization (ISO) describes the requirements and test methods for the physical properties of electric toothbrushes in order to increase the safety of these products in their intended use.

Electric toothbrushes have different technologies. The common features of electric toothbrushes that this standard applies to are:

• A battery
• An engine
• A mechanical or magnetic drive system
• A movable brush head with tufted filaments

Electric toothbrushes may have a movable brush head with different movements, frequencies and speeds (e.g. oscillating, rotating, side to side). The requirements listed in this standard apply to all types of electric toothbrushes. However, it is possible that some requirements may not apply to all types. For example, the brush head plate retention is only applicable if the brush has a head section that can be separated from the brush shaft.

This standard does not apply to other powered oral hygiene devices (such as electric interdental brushes) or manual toothbrushes.

For the purposes of this standard, in addition to the terms and definitions given in the “ISO 1942 Dentistry - Vocabulary” standard, the following definitions apply:

• The brush head is the working end of an electric toothbrush to which the filaments are attached.
• The filament is the single strand inside the brush head.
• An electric toothbrush is a hand-held, electrically operated device whose brush head carries filaments and is used primarily to clean surfaces in the oral cavity.
• Brush head removal force is the force required to remove the toothbrush tuft plate from the toothbrush shaft.
• A tassel is a group of filaments gathered together and attached to the brush head.
• Tuft removal force is the force required to remove a tuft from the brush head.

In terms of physical inspection, the electric toothbrush, its components and all accessories should be intact and free of visible dirt and sharp or rough surfaces when examined according to this standard.

For electrical safety, the electric toothbrush and related accessories must comply with the requirements described in the IEC 60335-1 and IEC 60335-2-52 standards.

The tassel holding (bunch removal) force shall not be less than 15 N when tested in accordance with this standard.

In terms of mechanical strength, the electric toothbrush and related accessories must comply with the requirements described in the standards IEC 60335-1 and IEC 60335-2-52. The holding force of the brush head plate must not be less than 50 N for each sample.

For resistance to chemical degradation, the brush head shall be subjected to a chemical degradation test in accordance with this standard. After this test, the brush head shall comply with the requirements of the spring-loaded impact test described in IEC 60335-1 and IEC 60068-2-75 and the brush head shall be in working order and free from sharp or rough surfaces when examined.

Eight electric toothbrushes of each type are tested. The electric toothbrushes sampled for testing must be as manufactured and must not be modified in any way other than those specified in this standard.

The pass-fail criteria are as follows: If none of the eight sampled electric toothbrushes fail, the electric toothbrush passes. If one toothbrush fails to meet the minimum requirements, the other eight electric toothbrushes are tested. If no more toothbrushes fail, the electric toothbrush passes. If two or more electric toothbrushes out of a total of 16 fail, the electric toothbrush fails.

In general, all tests are performed using dry brushes in an environment of 23 degrees plus/minus 5 degrees temperature and 50 percent plus/minus 10 percent relative humidity.

Test methods recommended in this standard include:

• Visual inspection: Visual inspection of the electric toothbrush and related accessories is performed using normal visual acuity without magnification.
• Tactile inspection: A tactile inspection of the electric toothbrush and related accessories is performed to detect sharp or rough surfaces.
• Tuft retention: When performing this test, the electric toothbrush is placed in the holder and locked in place so that the clamp pulls the tuft along the long axis of the tuft without any bending. The brush head should not be compressed during or after insertion. The clamp is placed over the filament cluster. All filaments are compressed in one tuft only, excluding filaments from surrounding tufts. The filaments of a tuft should be fixed approximately at the midpoint of the tuft length. Using the test apparatus, record the force required to remove the tuft. Two tufts of each tuft type are tested. The tufts should not be adjacent.
• Brush head plate holding: By adjusting the socket head screws on the brush head holder, the fixture is opened and the brush head is slid between the upper and lower vices. The brush head is placed between the upper and lower vices, leaving just enough space between the brush head holder and the grip plate to fit the grip unit onto the grip plate. Once the brush head holder is placed on the flat surface of the table, adjust the adjustment screws on the swivel head grips for both the upper and lower vices of the brush head holder until the grip plate of the brush head is parallel with the table surface.
• Resistance to chemical degradation: Chemical resistance is defined as the ability of a substance to protect itself against chemical attack over a period of time. Therefore, materials with high chemical resistance are less likely to corrode.

Our organization has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. Among the numerous test, measurement, analysis and evaluation studies provided for businesses in various sectors, there are also test services in accordance with the "ISO 20127 Dentistry - Fusisal properties of reliable tools" standard.