Date of Graduation

2001

Document Type

Thesis

Degree Type

MS

Committee Chair

Peter Ngan

Abstract

Decalcification around orthodontic appliances is an ongoing problem during orthodontic treatment. Argon laser irradiation has been shown to decrease the solubility of enamel. The objectives of this study were to: 1) determine the length of time necessary to create lesions of adequate depth, an intact surface zone, and a distinct body of the lesion zone; 2) determine if different wavelengths of argon laser irradiation (457-501nm or 457 514nm) of non-pumiced and non-etched enamel provided different levels of resistance to demineralization; 3) determine if different wavelengths of argon laser irradiation (457 501nm or 457-514nm) of pumiced and etched enamel provided different levels of resistance to demineralization. Time periods of 48 and 60 hours were investigated to determine which would produce the previously specified lesion criterion. Samples were suspended in Ten Cate’s solution for the appropriate time periods, thinned to 100µm, and examined under polarized light microscopy. Results show that 48 hours of exposure to buffered acidic solution (Ten Cate’s) was adequate to produce lesions with all the previously stated criterion. Two different lasers were used to determine if the wavelength of the laser made a difference in resistance of pumiced and etched enamel and non pumiced and non-etched enamel to acidic attack. One laser provided a 457-501nm wavelength and the other provided a 457-514nm wavelength. Samples were exposed to Ten Cate’s buffered acidic solution for 48 hours, thinned, and examined under polarized microscopy. Results of this study showed that different wavelengths of argon laser irradiation did not provide different levels of protection against acidic attack to pumiced and etched enamel when compared to non-pumiced and non-etched enamel.

Download

Share

COinS