Study the hardness and temperature changes during tooth bleaching using different Laser Sources


Background: Today, the processes of teeth bleaching by utilizing oxidation chemical components became a public
and important as a cosmetically operative. Particularly the demanding on these processes increased with the
developing in bleaching techniques, where laser light is used as catalyzer agent to increasing the efficiency and
speed of these processes, and the latter known as office bleaching. In this paper, we evaluate the effect of different
laser wavelengths of bleaching on the surface hardness of the tooth and the temperature rise of the pulp due to the
influence of laser light in conjunction with the bleaching gel.
Materials and methods: Three different laser sources (KTP 532nm, LD 810nm and Nd:YAG 1064nm) were used as
accelerator agent in-office bleaching utilizing Hydrogen Peroxide at 37.5%, where the enamel micro hardness
measurements in the teeth (invitro study) pre and post operative was done.
Results: Then by using analysis of variance (ANOVA-Tukey’s test r = 0.05 ) the results shows there are insignificant
effects on tooth hardness due to the changes in the laser wavelengths in both pre and post bleaching.
Conclusion: Thereafter to evaluate the pulp chamber temperature rise induced by three different light sources
employed in this laser-activated tooth bleaching, the pulp chamber temperature was measured during the radiation
processes and the results shows that the minimum temperature rise was seen at the 532nm. So, we can say that the
KTP (SHG) Nd:YAG laser at the wavelength (532 nm) represent the best choice to use in-office bleaching processes.
Keywords: Hardness, Tooth Bleaching, (SHG) Nd:YAG laser, (J Bagh Coll Dentistry 2010;22(4):41-46).