Assessment of Peroxide Level in Saliva During Teeth Bleaching With 9.5% Hydrogen Peroxide Gel Using a Tray With Reservoir Versus a Tray Without Reservoir. A Randomized Clinical Trial

Patients will be randomly divided into two groups. Alginate impressions of maxillary dental arches of patients will be taken to obtain casts and produce the customized trays. Reservoirs 1 mm thick will be created on the facial surfaces of anterior teeth, including the first premolars in the arches, applying a light-cured resin on the casts. The resin layer thickness will be standardized using a thickness gauge (1.5 mm thickness). Then, customized trays will be fabricated with 0.9-mm-thick vinyl acetate sheets using the thermoforming process. Trays will be precisely trimmed completely involving tooth surface (1 mm incisal or occlusal to gingival margin), and the adaptation will be verified on the casts. The trays will be placed over teeth to verify the adaptation in the patients' mouth.

Alginate impressions of maxillary dental arches of patients will be taken to obtain casts to produce the customized trays. Then, customized trays will be fabricated with no space for reservoir, with 0.9-mm-thick vinyl acetate sheets using the thermoforming process applying a light-cured resin on the casts. Trays will be precisely trimmed completely involving tooth surface (1 mm incisal or occlusal to gingival margin), and the adaptation will be verified on the casts. The trays will be placed over teeth to verify the adaptation in the participants' mouths.