Thesis (M.Sc.) - Cairo University - National Institute of Laser Enhanced Sciences - Department of Laser Application in Dentistry

This study was made to evaluate and compare the efficacy of 532 nm and 980 nm diode lasers when used with tooth bleaching. One hundred Twenty anterior teeth were taken. Before subjecting to bleaching agent the color of each specimen is measured using spectrophotometer, and morphological evaluation of the enamel surface by using scanning Electron microscope The 120 teeth were divided into three equal groups, as follows: - Group A (980 nm diode laser group): 40 teeth bleached with bleaching agent and diode laser 980 nm. - Group B (532 nm diode laser group): 40 teeth bleached with bleaching agent and diode laser 532 nm. - Group C (chemical agent group): as a Control group it is 40 teeth bleached with bleaching agent only. Then the color of each specimen is measured by using spectrophotometer, and morphological evaluation of the enamel surface of the all teeth was observed at 1500X magnification and At 3000X magnification by using SEM. This indicated that successful bleaching was achieved in all three groups. Specimens in the 532 nm diode laser group gave the greatest total color difference value (xE). This study showed significant difference in the changes of surfaces between the three groups, and showed that group A (980nm diode laser) treatments seems to have no significant effect on roughness of enamel surface, The laser treatments with (532nm diode laser) group B resulted in an increase in roughness of enamel surface, group C (Chemical) treatment lead to the process of drilling and formation of pores and this indicates the selective destruction of one of the components of the sample more than the other

Issued also as CD