Detection limit of the EPR signal for commercial composites, expressed as the time period needed for disappearance of the signal under the measurements conditions.

<p>The mass of the sample was 30 mg, a typical medium size restoration on an incisor.</p>*<p>detection threshold for the nine-lines signal. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062225#pone-0062225-t008" target="_blank">table 8</a> for nitroxide-like signal threshold.