A systematic approach to standardize artificial aging of resin composite cements

Objective. The aim of the investigation was to contribute to the ongoing discussion at the international standardization committee on how to artificially age dental resin composite cements. Methods. Indirect tensile strength (n=30) of a dual-cured resin composite cement (Panavia F2.0) was measured to evaluate the effect of water storage at 37 degrees C or thermal cycling (5 degrees C/55 degrees C/1 mm) for up to 64 days. The influence of water temperature (5-65 degrees C) after 16 days and the effect of 1 day water storage at 37 degrees C prior to aging were assessed. Storage in air at 37 degrees C served as control. Results. Thermal cycling affected the indirect tensile strength most, followed by water storage at 55 degrees C, whereas water storage at 37 degrees C had only little influence. Major deterioration occurred before day 4 cycles). A 1-day pre-treatment by water storage at 37 degrees C prior to thermal cycling attenuated the effect of aging. Signcance. For the material investigated, thermal cycling for 4 days is the most efficient aging procedure. A 1-day water storage at 37 C prior to thermal cycling is recommended to allow complete polymerization. A 4-day water storage at 55 degrees C may be considered as a viable alternative to thermal cycling. (C) 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.