Use of violet LED and argon plasma in dentin bleaching: effect on chromatic change, adhesive strength and temperature variation

• Grant number: 21/11788-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): January 01, 2022
• Effective date (End): December 31, 2022
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: André Luiz Fraga Briso
• Grantee: Camila Ferro Clemente
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The search for alternatives that promote a satisfactory bleaching treatment and that do not cause injuries to dental tissues has been growing, thus new therapies such as the use of violet LED and Argon Plasma are being implemented. This study will aim to evaluate in vitro the use of violet LED and argon plasma associated or not with oxygen in dentin bleaching, temperature variation, and bond strength. Therefore, 200 cylindrical dental blocks will be initially selected, taking into account the specimen's initial color (E value). After pigmentation with black tea, tooth enamel will be removed, resulting in 2mm thick dentin discs. These will be again evaluated at the top and bottom, with 75 discs selected with standardization of the initial color and pigmentation, which will be allocated into 5 groups (n=15): GI- Control group (without any bleaching therapy); GII- Argon Plasma (at 1 cm from the specimen for 10 minutes); GIII- 4% Argon + Oxygen Plasma (at 1 cm from the specimen for 10 minutes); GIV- Violet LED (3 irradiations of 20 minutes each); GV- Hydrogen peroxide (45 minutes with gel change every 15 min). Two bleaching sessions will be held with an interval of 7 days between them. During the first bleaching session, the samples will be connected to a type K thermocouple, and the temperature variation will be analyzed. After 24 hours, the samples will be re-evaluated in a portable spectrophotometer, and the chromatic alteration (”E) and the whitening index (WID) will be analyzed. Then, the samples will be polished, submitted to the second bleaching session, and immediately restored with composite resin, for the study of bond strength. The samples will be sectioned in orthogonal directions, obtaining eight sticks, four intended for the immediate microtensile test and four after thermocycling. After data collection, they will be submitted to the appropriate statistical tests for each analysis (p < 0.05).(AU)