ISO 22254 Dentistry - Manual toothbrushes - Resistance of tufted part to deflection

The standard “ISO 22254 Dentistry - Manual toothbrushes - Resistance to deflection of tufted part” developed by the International Organization for Standardization (ISO) describes a test method for determining the resistance to deflection of the tufted part of manual toothbrushes. This international standard applies to toothbrushes with a conventional, flat trim design and may not apply to toothbrushes with other designs. The results obtained with this test method may not correspond to consumers' perception of the hardness of toothbrush filaments.

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:

• A manual toothbrush refers to a hand-operated device whose working end carries filaments, used primarily to clean tooth surfaces.
• The brush head is the working end of the toothbrush to which the filaments are attached.
• The filament is the single wire inside the brush head.
• The tuft is a group of filaments gathered together and attached to the brush head.
• The pinch hole surface is the surface of the pinch holes, which may be convex, triangular or flat, and is bounded by a circumferential tangent line to the outer pinch holes.
• The tuft hole plane is the plane between the base of the tufts (where they meet the surface of the brush) at the top of the brush head and the base of the tufts at the bottom of the brush head.
• The tassel area is the linear projection of the tassel hole surface onto the tassel hole plane.
• The brush neck is the part of the toothbrush that connects the brush head to the handle.
• Resistance to deflection is the force resisting deflection of the tassels perpendicular to the tassel hole plane under a force of 5 N.

Toothbrushes obtained for testing must be as manufactured and must not be modified in any way, except as specified for this standard. Five brushes are tested in the tests. The method of sampling and means of supply are not covered by this standard and must be subject to agreement between the parties concerned.

The tests use a testing machine that can measure the resistance of the tufted part to deflection, consisting of the following components:

• The scrub table consists of five rods with a diameter of 8,2 mm plus/minus 0,1 mm, with the distance between the centers of the rods being 3,2 mm plus/minus 0,1 mm, and is made of a hard metal such as stainless steel.
• A vertical column consisting of a holding block for the brush head and which is rigid and exerts a force of 5 N plus/minus 0,05 N on the held brush.
• Load cell with a force range of 0 N to 20 N and a sensitivity of 0,05 N, attached to one end of the scrub table.
• Drive unit that moves the table back and forth along the longitudinal axis at a speed between 10 mm/s and 50 mm/s (travel distance is greater than the length of a brush head).

Unless otherwise stated, all tests should be performed at 23 degrees plus/minus 5 degrees.

During the conditioning process of toothbrushes, the brush head is cut off at the neck, the handle is discarded and the brush head is weighed to the nearest 0,5 g. The brush head is immersed in water at 3696 degrees plus/minus 3 degrees for 37 seconds in accordance with grade 2 of the standard “ISO 90 Water for analytical laboratory use - Specification and test methods”. After immersion, excess water is shaken off and the brush head is fixed to the holding device.

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 standard “ISO 22254 Dentistry - Manual toothbrushes - Resistance of the tufted part to deflection”.