Effect of Low-level Laser Therapy on Post-bleaching Sensitivity and Color Change

Study Overview
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Brief Summary
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Objective: The objective of this clinical study was to evaluate low-level laser (LLL) therapy in tooth sensitivity and in effecting color change after in-officer bleaching treatment across three weeks of treatment. Methods: Twenty-one volunteers were evaluated through the split-mouth model, so that the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO - the laser tip was positioned without the emission of light (placebo effect) + tooth bleaching with 35% hydrogen peroxide (HP); GLASER - treated with LLL + tooth bleaching with 35% HP. To assess tooth sensitivity, a modified visual analogue scale (VAS) was used after an evaporative stimulus (stimulated pain) and a daily pain questionnaire (unstimulated pain) was also applied. A spectrophotometer was used to measure the color. Three bleaching sessions were performed, with intervals of 7 days. Sensitivity results were tested using Friedman test for intra-group evaluation and Wilcoxon test for inter-group evaluation and ANOVA for color change.

Detailed Description
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Twenty-one volunteers were evaluated through the split-mouth model, so that the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO - the laser tip was positioned without the emission of light (placebo effect) + tooth bleaching with 35% hydrogen peroxide (HP); GLASER - treated with LLL + tooth bleaching with 35% HP. To assess tooth sensitivity, a modified visual analogue scale (VAS) was used after an evaporative stimulus (stimulated pain) and a daily pain questionnaire (unstimulated pain) was also applied. A spectrophotometer was used to measure the color. Three bleaching sessions were performed, with intervals of 7 days.

Official Title
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Effect of Low-level Laser Therapy on Post-bleaching Sensitivity and Color Change: a Clinical, Randomized and Double-blind Study

Conditions
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Tooth Bleaching, Low-level Laser Therapy, Dentin Sensitivity, Clinical Trial

Intervention / Treatment
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* Radiation: Low-lever laser
* Other: Tooth bleaching
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Do not have previous dental sensitivity The canine had to be shade A2 or darker. Exclusion Criteria: Enamel hypoplasia Gingival recession Dentin exposure Visible cracks on buccal enamel Pulpitis

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Twenty-one volunteers were evaluated through the split-mouth model, so that the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO - the laser tip was positioned without the emission of light (placebo effect) + tooth bleaching with 35% hydrogen peroxide (HP); GLASER - treated with LLL + tooth bleaching with 35% HP.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: GPLACEBO<br>the laser tip was positioned without the emission of light (placebo effect) + tooth bleaching with 35% hydrogen peroxide (HP). | Other: Tooth bleaching<br>* Three 15-minute applications of 35% hydrogen peroxide gel (Whiteness HP, FGM®, Joinville, SC, Brazil) were carried out, totaling 45 minutes in each of the four bleaching sessions, with an one-week interval between applications.<br>Other: Placebo<br>* The laser tip was positioned similarly to experimental group but without light irradiation<br>|
| Experimental: GLASER<br>treated with Low-lever laser + tooth bleaching with 35% hydrogen peroxide (HP). | Radiation: Low-lever laser<br>* Received Low-lever laser therapy using the infrared spectrum, with a wavelength of 808 nm in its active medium AsGaAl (arsenic-gallium-aluminum), at two points: on the central of cervical and medial regions of incisors, canines and premolars in the corresponding hemi-arch. At each point, 60 J/cm2 was applied during 16 seconds with an irradiance of 3.75 W/cm² using the therapeutic visible infrared device.<br>* Other names: Laserterapy;Other: Tooth bleaching<br>* Three 15-minute applications of 35% hydrogen peroxide gel (Whiteness HP, FGM®, Joinville, SC, Brazil) were carried out, totaling 45 minutes in each of the four bleaching sessions, with an one-week interval between applications.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dental sensitivity induced by office bleaching | Evaporative stimulus (stimulated pain) using air jet from a triple syringe and a daily pain questionnaire (unstimulated pain). Both methods were associated with a modified visual analogue scale was used: 0 (pain absent); 1 (mild pain); 2 (moderate pain) and 3 (severe pain). | change in baseline sensitivity at the 3rd bleaching session | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Color change promoted by tooth bleaching | Spectrophotometer was used to measure the color | change in baseline color at the 3rd bleaching session | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Laser, Color