ISO 10477 Dentistry - Polymer-Based Crown and Veneer Materials

The standard "ISO 10477 Dentistry - Polymer-based crowns and veneers," published by the International Organization for Standardization (ISO), classifies polymer-based crowns and veneers used in dentistry and describes the requirements. It also describes the test methods to determine compliance with these requirements. This standard applies to polymer-based crowns and veneers for laboratory-produced permanent veneers or crowns. It also applies to polymer-based dental crowns and veneers where the manufacturer claims adhesion to the substructure without macromechanical retention such as beads or wires.

For the purposes of this standard, the following definitions apply in addition to the terms and definitions given in ISO 1942:

• Polymer-based crown and veneer materials refer to a powder, liquid, or paste composition that may contain monomers, inorganic, or polymeric fillers and, once polymerized, is suitable for use as permanent dental veneers or crowns. Polymerization is achieved by mixing initiators and activators. Polymer-based crown and veneer materials for laboratory-produced permanent veneers or crowns may or may not be bonded to a substrate.
• Dentin resin is a pigmented and slightly translucent polymer-based crown and veneer material that mimics the appearance of natural dentin.
• Enamel resin is a translucent and lightly pigmented polymer-based crown and veneer material that is packed as a layer over dentin resin and mimics the appearance of natural enamel.
• Cervical resin is a densely pigmented and slightly translucent polymer-based crown and veneer material that mimics the natural appearance of dentin in the cervical region of the tooth.
• Opaque resin is a heavily pigmented polymer-based crown and veneer material applied in thin layers to completely mask and bond to the underlying material.

Polymer-based crown and veneer materials described in this standard should be classified according to their activation system for polymerization.

• Type 1: Polymer-based crown and veneer materials (self-curing materials) that are hardened by mixing initiators and activators.
• Type 2: Polymer-based crown and veneer materials that are hardened by the application of energy from an external source such as heat or radiation (visible or UV range).
  • Class 1: Polymer-based crown and veneer materials that do not contain photopolymerization initiators.
  • Class 2: Polymer-based crown and veneer materials containing photopolymerization initiators.
• Type 3: Polymer-based crown and veneer materials (dual cure materials) whose curing is achieved by mixing initiators and activators and applying energy from an external source.

The tests required for a crown and veneer material depend on its classification by type and grade.

For all tests, the test sample consists of one or more packages of a shade selected in accordance with the purpose of the test and contains sufficient material (approximately 20 ml) to perform the specified tests, plus an allowance for the necessary test repetitions.

For shade consistency testing the sample should consist of the shade as above (approximately 1ml) but from another batch.

For color stability testing, the sample should consist of two additional shades of the material. The shade of the resin sample should consist of three different shades (approximately 1 ml per shade), each corresponding to a representative shade of enamel resin, dentin resin, and cervical resin. If different color components are used, the color components should be selected with consideration.

The ISO 10477 standard outlines various test methods for evaluating the mechanical, physical, and chemical properties of polymer-based dental materials. These methods are used to assess the suitability of the material for clinical use. The main test methods are:

• Flexural strength test: This test is performed to evaluate the material's resistance to bending. A three-point bending test, described in the ISO 4049 standard, is used. The minimum flexural strength (typically 80 MPa for permanent crown and bridge materials) is
• Water absorption and solubility: This test is used to measure the stability and resistance to degradation of a material in the oral environment. It uses the test method defined in the ISO 4049 standard. Defined maximum limits for water absorption and solubility are established.
• Degree of conversion (if applicable to polymerized materials): This test is used to determine the extent to which monomers have completely converted to polymer, particularly for materials polymerized in the mouth. It is usually measured indirectly via infrared spectroscopy (FTIR) or based on elution monomer tests.
• Color stability: This test is performed to ensure that the material maintains its aesthetics over time. Materials are exposed to staining agents or light aging, and color changes are measured spectrophotometrically.
• Bond strength (for coating materials): This test is used to test the adhesion between the core and coating materials. Shear or tensile bond tests are performed.
• Thermal cycling (optional for durability assessment): This test simulates the oral environment by cycling between hot and cold baths to evaluate fatigue and deterioration.
• Biocompatibility: Based on the ISO 10993 set of standards for biocompatibility testing, including cytotoxicity, sensitization and genotoxicity.

The IOS 10477 standard also defines test conditions (e.g. temperature, humidity), sample preparation, and test times.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the "ISO 10477 Dentistry - Polymer-based crown and veneer materials" standard.