The Effectiveness of At-home , In-office and Combined Dental Bleaching System ：A Randomized Controlled Clinical Trial

Study Overview
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Brief Summary
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This randomized controlled clinical trial aimed to investigate the effectiveness of at-home , in-office and combined dental bleaching system.

Detailed Description
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The participants with at least one maxillary tooth demonstrating shade A3 or darker will be recruited and randomly allocated into 4 groups according to the different tooth bleaching protocol：at-home bleaching for group 1,in-office bleaching for group 2 ,combined bleaching for group 3 and group 4.Participates in group 1 will receive two weeks of at-home tooth bleaching （Lasts 14 days and at least 8 hours every day ）with 10% Carbamide peroxide(Opalescence PF 10%) , group 2 will receive two sessions （with a 1- week interval ）of in-office tooth bleaching with 40% hydrogen peroxide (Opalescence Boost PF 40%)，group 3 will receive one week of at-home tooth bleaching （Lasts 7 days and at least 8 hours every day ）and then the eighth day receive one session of in-office tooth bleaching , group 4 receive one session of in-office bleaching and lasts 7 days at-home bleaching start on the eighth day . Colour parameters (CIE L*, a*, b*) will be measured with a spectrophotometer (Vita Easyshade Advance 4.0) at baseline (T1), after the first bleaching session (T2), after the second bleaching session (T3), 1 month after the completion of bleaching (T4). CIEDE2000 colour difference (△E00), the Whiteness Index for Dentistry (WID) and Tooth sensitivity (TS) will also be calculated. The data will be statistically analysed through repeated ANOVA and Tukey's test (α = 0.05).

Official Title
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The Effectiveness of At-home , In-office and Combined Dental Bleaching System ：A Randomized Controlled Clinical Trial

Conditions
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Tooth Bleaching

Intervention / Treatment
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* Procedure: different combined of tooth bleaching procedure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients between 18 and 30 years of age, with fully erupted upper and lower incisors and canines without dental or periodontal disease or restorations, and with at least one maxillary tooth presenting color score A3 or darker, as measured with the Vita Classical guide (Vita Zahnfabrik, Bad Sa # ckingen, Germany) ordered by brightness Exclusion Criteria: patients with systemic diseases or oral mucosal disorders, previous bleaching treatment, patients undergoing orthodontic treatment, pregnant or lactating women , people with known allergy to the product ingredients, smokers, and alcohol abusers, had severe internal tooth discoloration (e.g. tetracycline stains), had bruxism or any other pathology that could cause TS (such as gingival recession or dentin exposure).

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: Factorial Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: group 1: have two weeks of at-home tooth bleaching<br>Participants will receive two weeks of at-home tooth bleaching with 10% Carbamide peroxide(Opalescence PF 10%) for the maxillary anterior teeth. | Procedure: different combined of tooth bleaching procedure<br>* The participants will be randomly allocated into 4 groups and receive different kind of tooth bleaching protocol.<br>|
| Experimental: group 2 : have two sessions of in-office tooth bleaching<br>Participants will receive two sessions（with a 1- week interval ） of in-office tooth bleaching with 40% hydrogen peroxide (Opalescence Boost PF 40%)for the maxillary anterior teeth. | Procedure: different combined of tooth bleaching procedure<br>* The participants will be randomly allocated into 4 groups and receive different kind of tooth bleaching protocol.<br>|
| Experimental: group 3 : one week of at-home and then have one session of in-office tooth bleaching<br>Participants will receive one week of at-home tooth bleaching with 10% Carbamide peroxide(Opalescence PF 10%) and then receive one session of in-office tooth bleaching with 40% hydrogen peroxide (Opalescence Boost PF 40%)for the maxillary anterior teeth. | Procedure: different combined of tooth bleaching procedure<br>* The participants will be randomly allocated into 4 groups and receive different kind of tooth bleaching protocol.<br>|
| Experimental: group 4 : one week of in-office and then have one session of at-home tooth bleaching<br>Participants will receive one session of in-office tooth bleaching with 40% hydrogen peroxide (Opalescence Boost PF 40%) and a week later receive one week of at-home tooth bleaching with 10% Carbamide peroxide(Opalescence PF 10%)for the maxillary anterior teeth. | Procedure: different combined of tooth bleaching procedure<br>* The participants will be randomly allocated into 4 groups and receive different kind of tooth bleaching protocol.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in tooth colour | Colour parameters (CIE L*, a*, b*) will be measured with a spectrophotometer (Vita Easyshade Advance 4.0). The color alteration after each session will be given by the differences between the values obtained at the sessions and the baseline (∆E). | six weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tooth sensitivity evaluation | Using the visual analogue scale (VAS) record the Tooth sensitivity (TS) throughout the entire treatment | two weeks |