{'fraction_non_alphanumeric': 0.009746588693957114, 'fraction_numerical': 0.0, 'mean_word_length': 5.119047619047619, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Wear of Human Enamel and Dentin

The wear of human tooth enamel and dentin has been studied and compared using a repetitive constant load scratch test. Depth sensing indentation with spherical tip was used for measurement of hardness and reduced modulus. An analysis of residual wear tracks was performed with scanning laser confocal microscopy. A procedure for evaluation of repetitive scratch test was proposed. Results showed that the microtribological behavior of enamel differs obviously from that of dentin.