Comparison the effect of visible and invisible laser irradiation on sensitivity and color of teeth after bleaching in patients with discolored teeth: A randomized clinical trial

Our main objectives are evaluation the effect of low power visible and invisible laser irradiation on the sensitivity and color of teeth after bleaching. This is a randomized, single blind and placebo-controlled study. Patients who agree to participate in the study will be chosen. Patients with six healthy sound maxillary anterior teeth will be included in the study and patients with tooth sensitivity before bleaching treatment and severe tooth discoloration will be excluded from the study. Patients will be divided into 3 groups randomly. Randomization will be performed by choosing sealed envelopes containing different treatment protocols. After isolation, the anterior maxillary teeth will be bleached with Hydrogen Peroxide 35% gel according to manufacturer’s instruction. After the end of bleaching procedure, in experimental groups, the low power diode laser; “Thor” (with 660 or 810 nm wavelength, power density 800 mW/cm2, energy density 12 J/cm2, output power 200 mW) will be used on the cervical third of each tooth in contact mode with surface area of 0.25 cm2 for 15 seconds. To consider the placebo effect in control group turned-off laser will be used in the same manner as experimental groups. For each patient two bleaching sessions with one week interval will be done. The pain intensity will be measured based on visual analogue scale immediately, 24 and 48 hours after the end of the bleaching procedure. The color change will be evaluated 30 days after the end of the bleaching procedure with optical and instrumental methods.

Vice Chancellor for Research, Mashhad University of Medical Sciences