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In Europe, denture Base Hot/Cold Cure Acrylics have to be CE-Certified in class IIa and the physical properties are tested in accordance with ISO 20795 (2008); Base Polymers – part 1 Denture base polymers. This international standard replaces the well known ISO 1567 (2001).

There is a complete misunderstanding saying that Hot Cure acrylics are better than Cold Cure acrylics. So it is time to give a full and detailed explanation in this regard.

To keep control of Premium quality, the ISO/TC106 committee specified the limits of Denture base polymers for their application as a denture in the mouth of a patient.

The most important properties to compare materials are:

The flexural strength which actually explains the endurance of a materials in the mouth, tested through three-point bending.

The flexural modulus says something about the capability of the material to absorb forces, in other words the elasticity of materials.

The water sorption says something about the amount of absorbing liquids by the denture for instance coffee or tea.

The water solubility gives an indication about the migration of materials out of the denture for instance rest monomer.

Charpy impact strength is the capability to absorb impact forces (embedding/dropping) on the denture.

Color stability gives an indication about the stability in color of the denture in relation with time for instance by aging of the accelerator systems or discolorisation of the pigments.

Bonding to the acrylic teeth where 5 out of 6 teeth must show no clean bonding surface after having been removed by pulling force.

So let us compare the ISO 20795: type I, class 1 standards for Heat Cured denture base polymers with our Cold Cure Vertex Castavaria properties and the result are amazing:

The flexural strength:
- Physical prop. Acc. ISO20795
at least 65 MPa

- Vertex Castavaria
72 ± 2 MPa

The flexural modulus:
- Physical prop. Acc. ISO20795
at least 2000 MPa

- Vertex Castavaria
2149 ± 47 MPa

The water sorption:
- Physical prop. Acc. ISO20795
no more than 32µg/mm³

- Vertex Castavaria
25.5 ± 0.3µg/mm³

The water solubility:
- Physical prop. Acc. ISO20795
no more than 1.6µg/mm³

- Vertex Castavaria
1.3 ± 0.2µg/mm³

Charpy impact strength: 
- Physical prop. Acc. ISO20795
at least 8 kJ/m² (unnotched) 
- Vertex Castavaria
9.1 ± 1.1 kJ/m²

Color stability:
- Physical prop. Acc. ISO20795
no chance in color
- Vertex Castavaria
comply

The conclusion is that Vertex Castavaria is superior because it reaches all specification limits in accordance with ISO 20795: type I, class 1 for Hot / Heat Cure denture base polymers.

Zeist, 15-09-2010 by Rik Jacobs / Connie Peterse van der Koppel