Clinical evaluation of bleaching efficacy, sensitivity, and oxygen level of the dental pulp when tooth bleaching with titanium dioxide nanoparticles associated with fluorine and nitrogen

INTERVENTION: This is a randomized, controlled, parallel, blinded clinical trial. Experimental group 1: 24 healthy individuals, with teeth darkened to A2 according to visual scale or darker, will be submitted to tooth bleaching with an experimental gel containing carbomer 940 thickener and titanium dioxide nanoparticles co‐doped with fluorine and nitrogen (NF_TiO2), associated with 6% hydrogen peroxide and violet LED irradiation (20 repetitions of 1min with consecutive intervals of 30 seconds). Experimental group 2: 24 healthy individuals, with teeth darkened to A2 according to visual scale or darker, will be submitted to tooth bleaching with an experimental gel containing hyaluronic acid thickener and titanic dioxide nanoparticles co‐doped with fluorine and nitrogen (NF_TiO2) associated to 6% hydrogen peroxide and violet LED irradiation (20 repetitions of 1min with consecutive intervals of 30 seconds). Control group: 24 healthy individuals, with teeth darkened to A2 according to the visual scale or darker, will be submitted to tooth bleaching with 35% hydrogen peroxide without irradiation with violet LED. In all groups, 3 sessions will be held, that is, 3 consultations, and the gel will be in contact with the dental structure for 30 minutes in each consultation with an interval of 7 days between each consultation. CONDITION: Tooth discoloration PRIMARY OUTCOME: Evaluate promoted color change. It will be verified through a comparison between the tooth color before whitening and the tooth color after whitening. The measurement will be performed using a manual spectrophotometer (Easyshade) and a standardized visual scale ‐ Vita Scale. The color change calculation will be performed using the final‐initial values. Data will be transformed into delta WID and delta E values (CIEDE 2000) SECONDARY OUTCOME: Evaluate pulp oxygenation after bleaching treatments. Method: it will be performed under isolation with a cotton roll and constant suction to ensure the dryness of the dental surfaces involved and in the absence of reflected light. Participants will be placed in a supine position and instructed to remain silent during the vitality test. The sensor with the prefabricated adapter will be placed on the tooth of interest so that the emitted light reaches the middle third of the crown and the emitting diode and the photodetector. Two measurements will be obtained, one in the first minute after placing the sensor on the tooth and the second, 1 minute after the first measurement, and will be averaged. This procedure will be performed before and after each whitening session Evaluate the intensity of sensitivity after bleaching treatments. Method: volunteers will mark the intensity of pain from 0 to 10 on a visual analogical scale (VAS) during the consultation and in the following session they will do the same about the experience during the interval between whitening sessions. The numbers marked on the scale by each patient will be used to quantify the outcome of each group, obtaining an average for values during the session and another average for values between sessions INCLUSION CRITERIA: Provide written and signed consent; Complete the vaccination schedule for COVID‐19; Agree NOT to participate in another clinical trial during the course of the project; Present good general and oral health; Have not undergone dental bleaching in the last 3 years or have undergone it in the last 3 years, but have teeth darker than color A2; Having vital teeth in question (Positive response to the cold sensitivity test, absence of signs or symptoms of pulpal or periapical pathology, absence of radiographic signs of periapical pathology); No edentulous space between the premolars of each arch (upper and lower); Upper incisors must be classified as A2 or darker in color and free of caries and/or restoration; Age (over 18 and under 30); Being in treatment or other activities in FOP, not generating the need for exclusive visits for the research