efficacy of laser application in dental bleaching

Conditions: Tooth Discoloration

Summary: objective: to establish the efficacy of laser application with chemical treatment in dental bleaching compared to chemical treatment alone. methods: the investigators conducted a randomized controlled trial (rct), single blind (evaluator), in 24 patients randomized to laser and chemical intervention (12) or chemical intervention aloe (12). the commercial products used were whiteness hp 35% hydrogen peroxide and the laser of dcm equipments. the trial outcome measures were obtained using the vita easyshade spectrophotometer and the international cielch system. to stablish differences before vs. after treatments and between groups, the t test and chi2 tests were applied.

new technologies continue to be launched in the field of dental esthetics, especially for whitening, and many products advertise their efficacy. one new approach is the use of laser technology which has been purported to be the most powerful font light for bleaching diverse studies by different designs find different efficacies for laser whitening randomized clinical trials (rct) are needed for the most rigorous confirmation of efficacy. rct are able to control for characteristics that can cause bias, including factors related to dental care such as diet and cleaning behavior after the bleaching procedure. the investigators therefore conducted an rct to make a side by side comparison of a laser whitening technique with chemical bleaching versus chemical bleaching without laser. intervention: after the patient was informed and sign the consent; a dental prophylaxis was done. three days later the bleaching procedure started following the same protocol regarding to the time and product used (35% hydrogen peroxide whitening hp, 40 minutes divided in two phases of 20 minutes each one) from premolar to premolar in superior and inferior teeth. the difference was that one of the intervention groups used the laser for ten minutes (starting at the minute 5) and the other did not.. the laser used was the whitening lase ii (dcm equipments). the measure of the color was done to the superior canines by just one evaluator in three stages: before bleaching (baseline), 15 minutes after bleaching, and three days after. it was done with the vita easyshade spectrophotometer. the dental sensitivity also was asked at the three time points; however, as an exclusion criterion the level had to be 0 to be entered into the study. all the patients received verbal and written instructions about eating and cleaning behavior. cleaning materials for the three days after procedure were given. as the clinical endpoint, the difference in color was calculated using the international accepted system cielch (11,18-19). the formula is ∆e\* = \[(∆l\*)2 + (∆c\*)2 + (∆h\*)2\] ½; were l is luminosity, c is chroma and h is hue. a verbal numeric scale was used to determine the dental sensitivity with values from 0 to 3. the evaluator used the water and air from the dental chair syringe. the patient reports 0 for no sensitivity; 1 for slight sensitivity, 2 for moderate sensitivity, and 3 for severe sensitivity.

Eligibility criteria:
inclusion criteria: * patients who wanted to bleach or whiten their teeth. exclusion criteria: * patients who have a color less than a2 according to the vita scale * patients with dental sensitivity * caries or restorations * periodontal disease * dental abfraction or attrition * pregnant women, smokers * patients with orthodontics * nauseous reflects * patients who did not wish to sign the consent.

Keywords: bleaching laser cielch