Polymer composite fillings of root-canal treated teeth can fail over time. Scientists led by the Charité University in Berlin (Germany) have found that this is not because of the dentist’s lack of skills but rather because of stresses that build up and deform the biomaterial just after it is placed. The results are published in Acta Biomaterialia.
It is one of the most peculiar images that can come to mind: a dentist restoring severely destroyed teeth and placing fillings on a beamline at a synchrotron. It is, however, exactly what happened on beamline ID19 a while back, when a team from the Charité and TU Universities in Berlin and the ESRF examined how well composite fillings adapt to cavities in the tooth root canal orifice.
To treat cavities in teeth, dentists expose solid tooth tissue prior to “filling” the volume of missing structure with rigid biomaterials that sustain chewing forces. In the past, dentists used metals such as amalgam or gold, but today they mostly use composite materials, made of polymer and glass. Such materials, which are well resistant to damage and highly aesthetic, allow rapid recovery of tooth function. However, composites tend to fail in the long run, especially in root-canal filled teeth.
Read more on the ESRF website
Image: Kerstin Bitter placing a filling on a tooth on ID19’s experimental hutch.
Credit: P. Zaslansky.