{'fraction_non_alphanumeric': 0.01759014951627089, 'fraction_numerical': 0.003518029903254178, 'mean_word_length': 5.322222222222222, '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}}
Effect of bleaching products on the collagen of teeth

Americans spend an estimated 1.4 billion dollars on over‐the‐counter bleaching products which whiten teeth. The active ingredient is hydrogen peroxide which can damage proteins. The dentin contains an estimated 90% of its protein in the form of collagen and the effect of bleaching on collagen has not been determined. In this project, the non‐collagen proteins from teeth were extracted with EDTA and the remains of the teeth were dialyzed against water and then pulverized with liquid nitrogen. The resulting powder was re‐suspended and treated with pepsin to produce fragments. The protein level of these fragments was tested using the Lowry assay and individual fragments were separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). Individual fragments were removed and hydrolyzed to produce amino acids which were separated and identified using reverse phase high performance liquid chromatography. This was done on untreated teeth as well as teeth that had received either one or three rounds of tooth whitening with an over‐the‐counter product.