YY/T 1599-2018Dentistry—Test method for polymerization shrinkage of polymer-based restorative materials—Laser ranging method (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

Introduction

Dental polymer-based repair materials, especially photocurable polymer-based repair materials for filling and restoration, have become clinical therapeutic applications The mainstream, one of the hidden dangers of such materials in therapeutic applications that may lead to treatment defects is the polymeric shrinkage properties of the material. Currently, there are more Methods for measuring the polymerization shrinkage of dental polymer-based repair materials include. density method, dilatometer method, image analysis method (Accvol method), electricity Resistance strain gauge method and curved sheet method.

Density method is a method for indirectly measuring the shrinkage rate of a polymer-based repair material before and after polymerization shrinkage.

ISO standards have been formed. However, since the method measures the density of the material itself, it is also necessary to measure the density of the container in which the material is placed.

Degree, and the measurement results are sensitive to ambient temperature; the method also needs to measure the buoyancy of the material sample before and after curing in an aqueous solution.

The polymer-based repair material itself has water absorption characteristics, and the surface is also easy to adsorb bubbles when measured in a liquid, which affects measurement accuracy. because Therefore, this method has many interference factors and is prone to errors.

The dilatometer method is a method for measuring the polymerization shrinkage of a material by using a polymer-based repair material to cause a change in liquid level caused by polymerization shrinkage in a container. law. However, this method is greatly affected by temperature because even a small temperature change can affect the volume change of the liquid itself.

During the test, the test temperature must be carefully maintained to maintain the volume of the liquid medium in the experiment unaffected. This method detects errors in real time The difference is large.

Image analysis (Accvol method) is a projection of hemispherical polymer-based repair material samples based on laser scanning and optical measurement techniques.

The method of real-time measurement of the shape. During the measurement, the change of the hemispherical projection is converted into the change of the hemispherical volume by calculation, and the sample is obtained.

Polymer shrinkage. However, since the light source of the curing light interferes greatly with the optical signal, it cannot monitor the polymerization shrinkage of the sample during photocuring. Dynamic changes.

The resistance strain gauge method uses a biaxial strain gauge to measure the shrinkage of two polymer-based repair materials in two perpendicular directions. shape. However, the resistance strain gauge sensor can only sense the polymerization shrinkage after the elastic modulus of the polymer-based repair material reaches a certain level.

The change does not measure the total polymerization shrinkage of the material.

The bending sheet method (deflecting disc method) is to put a composite resin material in a copper ring placed on a glass plate, and a copper ring cover A thin piece of glass and in contact with the composite resin. The curing light is irradiated upward from the glass plate to cure the composite resin. Thin glass upper surface Contact with the sensor to monitor the change in curing shrinkage of the composite resin. The method obtains the amount of curing shrinkage in the direction of illumination, and the sensing The dimensional change directly measured by the device is the deformation of the thin glass piece, although the deformation of the thin glass piece is caused by the shrinkage of the composite resin, but due to the thin glass The piece is supported on the copper ring, and is bent by the rigidity of the copper ring when it is bent downward. Therefore, the measurement cannot overcome the rigidity constraint of the glass piece at an early stage. Shrink.

The polymerization shrinkage measurement method proposed in this standard is laser ranging method, which uses the principle of laser ranging, non-contact, real-time measurement of dentistry Polymer-based repair materials change from the pre-photopolymerization to the polymerization shrinkage of the material into a solid state.

1 Scope

This standard specifies the test equipment and test methods for the laser ranging method for measuring the polymerization shrinkage properties of dental polymer-based repair materials.

This standard is mainly applicable to photocurable polymer-based repair materials and filling repair materials by photoinitiated polymerization.

This standard does not apply to chemically cured and dual cured (Class I and Class III) polymer based restorative materials.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 9937 Oral Vocabulary (all) (ISO 1942:1989, IDT)

3 Terms and definitions

The following terms and definitions as defined in GB/T 9937 apply to this document.