ISO 17304 pdf download

ISO 17304 pdf download Dentistry — Polymerization shrinkage: Method for determination of polymerization shrinkage of polymer-based restorative materials
Scope
This International Standard specifies a test method for the measurement of the polymerizationshrinkage of external energy-activated polymer-based restorative materials such as composites andcore materials.
The method is not suitable for Class 1 (self-curing, see ISO 4049) polymer-based restorative materials.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application, For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies.
SO 1183-1, Plastics — Methods for determining the density of non-cellular plastics — Part 1: lmmersionmethod, liquid pyknometer method and titration method
ISO 1942, Dentistry- Vocabulary
ISO 3696:1987, Water for analytical laboratory use — Specification and test methodsISO 4049,Dentistry – Polymer-based restorative materials
ISO 10650 (all parts), Dentistry – Powered polymerization activators
3 Terms and definitions
For the purposes ofthis document, the terms and definitions in ISO 1183-1,IS 1942,ISO 4049, and thefollowing apply.
31
high-viscosity materialspolymer-based restorative materials having little flow so that they hold their shape on moulding
3.2flowable materials
polymer-based restorative materials having lowviscosity so that they do notholdtheir shape on moulding
4 Test method
4.1 Principle
The polymerization shrinkage of external energy-activated polymer-based restorative materials isdeterminedusing densitydeterminations in accordance with the buoyancymethod (Archimedes’principle)This test method accords with method A (immersion method), described in general terms in ISO 1183-1.
Ensure that test conditions such as temperature, duration of exposure, and distance between light guideand the test specimen are controlled and reproducible, Pre-test storage conditions of the polymer prior to its measurement are also specified to ensure the maximum achievable polymerization in the test conditions so that the most complete possible shrinkage of the materials will be achieved. This way,differences in the rate of polymerization will, to a large extent, be balanced out.
4.2 General
Perform all measurements at a room temperature of (23 ± 2) °C.
Store all specimens at a temperature of (23 ± 2) °C for at least 30 min before the start of measurement.
Perform all measurements of the unpolymerized specimens under yellow light.
NOTE 1 Yellow light may be created by filtering ambient lighting with a suitable filter 1) .
When handling test materials, wear appropriate rubber gloves, e.g. latex or nitrile.
The temperature fluctuation during the measurement of the unpolymerized specimens and the polymerized specimens shall be less than 1,0 °C.
NOTE 2 Measurements can be performed at temperatures between 21 °C and 25 °C. Temperature variations during measurement below 1,0 °C do not significantly influence the results.
Perform the corresponding density measurements for the unpolymerized and the polymerized specimens on the same day.