New model to explain tooth wear with implications for microwear formation and diet reconstruction

Dental microwear is among the most common proxies paleontologists use for diet reconstruction. Recent models have suggested that while quartz grit adherent to food produces wear of tooth enamel, softer particles, such as silica phytoliths found in many plants, do not. Some have therefore suggested that microwear patterns better reflect habitat than diet. This is important to paleobiologists because reconstructions of species from the earliest vertebrates to human ancestors have relied on dental microwear as a proxy for diet. Here we present an in vitro study demonstrating that softer particles produce microwear under conditions mimicking chewing. Enamel wear occurs not because an abrasive is hard but because it exceeds the binding force of proteins that hold together hydroxyapatite crystallites.