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Thomas Library

Honors Thesis Archive

Author Natalie Muir
Title The Effects of HCl, NaOH, and Whitening Products on Human Teeth
Department Chemistry
Advisor Mark Ellison
Year 2005
Honors University Honors
Full Text View Thesis (881 KB) Note: This is a very large file; it may be easier to download the file to your computer and open it from there.
Abstract The effects of hydrochloric acid, sodium hydroxide, Crest Whitestrips®, Colgate Simply White®, Coke®, and Pepsi® on teeth were examined in this study. The teeth were placed in HCl or NaOH for four days, and the whitening products were applied once as suggested on the box. Two teeth remained in deionized water for four days to act as a control in the study. Two teeth were placed in the cola products for three days to investigate the effects of phosphoric acid which is present in Coke® and Pepsi®. Atomic absorption spectrophotometry was used to detect the concentration of calcium ions released from the tooth enamel, and a reflectivity experiment was performed to analyze the whitened teeth before and after whitening treatments. Scanning electron microscopy was used to examine the surface of each tooth before and after the treatment in solution. Results from atomic absorption spectrometry and scanning electron microscopy suggest that hydrochloric acid destructs the enamel structure, releasing calcium ions in solution.

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