ISO 20126 Dentistry - Manual Toothbrushes - General Requirements and Test Methods

The “ISO 20126 Dentistry - Manual toothbrushes - General requirements and test methods” standard, developed by the International Organization for Standardization (ISO), describes the requirements and test methods to determine the physical properties of manual toothbrushes in order to promote the safety of these products for their intended use.

This standard does not specify any requirements or test methods for the physical properties of toothbrushes whose entire cleaning element in the head is elastomer.

This standard does not apply to manual single-tuft toothbrushes, disposable, interdental and electric oral hygiene devices. Such oral hygiene products are evaluated for their safety in use by appropriate test methods or clinical trials.

Additionally, this standard for filament end-rounding requirements does not apply to certain types of filaments that are very thin (less than 0,1 mm outside diameter) or have no sharp edges (e.g., pointed, feathered, split-ended, or spherical caps), or to non-synthetic filaments for which end-rounding is inappropriate or impossible. Such manual toothbrushes shall be appropriately evaluated for safety in use by appropriate test methods or clinical trials.

For the purposes of this standard, the terms and definitions given in ISO 1942 Dentistry - Vocabulary and ISO 22254 Dentistry - Manual toothbrushes - Resistance of the tufted part to deflection, as well as the following definitions, apply:

• A manual toothbrush is a hand-operated piece of equipment. The working end carries filaments to clean surfaces mainly within the oral cavity.
• The filament is the single wire inside the brush head.
• Tuft removal force is the force required to remove a tuft from the brush head.
• The tuft hole plane is the plane between the base of the tufts at the top of the brush head and the base of the tufts at the bottom of the brush head (where they meet the tuft hole surface).
• The period of oscillation of a pendulum is the period, expressed in seconds, during which a single complete swing of the pendulum oscillates at an average angle of oscillation of less than 5 degrees to either side of the vertical.
• The center of impact is the point on the pendulum at which a perpendicular impact in the plane of oscillation does not cause reaction forces in the axis of rotation of the pendulum.
• The pendulum length is the distance between the axis of rotation of the pendulum and its center of impact. It is equal to the equivalent theoretical pendulum mass concentrated at the point that gives the same period of oscillation as the real pendulum.
• The stroke length is the distance between the axis of rotation of the pendulum and the striking edge of the pendulum.
• Tip rounding is a manufacturing procedure for toothbrushes to eliminate the sharp edge at the free end of the filaments.

The pass-fail criteria, excluding filament end rounding, are as follows: Eight manual toothbrushes are tested. If none of them fail, the sample set passes. If one sample does not meet the minimum requirement, eight more manual toothbrushes are tested. If no more samples fail, the toothbrush passes. If two or more of the 16 samples fail, the toothbrush fails.

The pass-fail criteria for filament tip rounding are as follows: All filaments from three strands of three randomly selected toothbrushes are used for this test. If the brush head contains two or more filament types, all filaments from three strands of each type are tested. If none of the three toothbrushes fail, the sample set passes. If one sample fails the minimum requirement, the other three toothbrushes are tested. If no other sample fails, the toothbrush passes. If two or more of the six samples fail, the toothbrush fails.

In physical examination, the toothbrush should be intact and free from visible contamination and sharp or rough surfaces when examined according to the standard. The hair removal force should be at least 15 N. In terms of handle impact resistance, the handle should not break when tested according to this standard. However, if the handle breaks, the minimum absorbed energy at the moment of breakage should be 0,8 J.

In terms of fatigue resistance, it must complete 75.000 cycles without breaking when tested. The toothbrush must demonstrate the expected resistance after being subjected to chemical challenge.

Filament The percentage of filaments without sharp geometries at their tips must be at least 50 percent to ensure a level of safety in use for oral soft tissues. This requirement does not apply to certain types of filaments that are very fine (less than 0,1 mm outside diameter) or have no sharp edges (e.g. tapered, feathered, split-tipped or spherical caps), or to non-synthetic filaments for which tip rounding is inconvenient or impossible. Such manual toothbrushes must be appropriately evaluated for safety in use.

For testing, toothbrushes are taken as manufactured and not modified in any way other than those specified in this standard. Tests are carried out using dry toothbrushes at a temperature of 23 degrees plus/minus 5 degrees and a relative humidity of 50 percent plus/minus 10 percent.

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 20126 Dentistry - Manual toothbrushes - General requirements and test methods" standard.