Effect of two artificial aging protocols on direct veneer retreatment using different removal methods

• Grant number: 22/10741-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2023
• End date: December 31, 2023
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Ticiane Cestari Fagundes
• Grantee: Yasmine Parischi Musa Ali
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

During the retreatment of direct veneers, the dentists find difficulties to remove all restorativematerial without unnecessary wear of the healthy tooth structure or the permanence of remnantsof the restorative material. The consumption of food colorants, aging and cigarette smokingchanges the color and fluorescence of the composite resin, negatively interfering with its removalwhen an ultraviolet light (UV) device is used. Thus, the objective of this study will be to evaluatethe effect of pigmentation and artificial aging of composite resin in the retreatment of directveneers using different removal methods, in relation to dimensional alterations. Ninety bovineincisors will be selected, the dimensions of their crowns will be reduced to 10 x 8 mm and thecolor of the specimens will be standardized to the A3 shade. All specimens will receive the initialscan (T0). Then, they will receive the direct veneer preparation, they will be scanned again (T1)and distributed into 6 groups according to the removal method (conventional high rotation andhigh rotation with UV light), and the type of artificial aging of the specimens (pigmentation withcoffee and cigarette smoke exposure). The veneers will be made with an adhesive system andcomposite resin. The two artificial aging protocols will be: 12 days of immersion in solublecoffee and 20 cigarettes a day for 5 days. The veneers removal will be carried out according tothe established removal methods. Then, the specimens will receive a new scan (T2) and theareas of dental wear, areas of presence of composite resin residues and the average betweenwear and presence of residue between T2 and T1 will be evaluated. The data will be submittedto the statistical test of normality and homogeneity. If the results pass the tests, the dimensionalchange data between T2 and T1 will be analyzed using parametric tests, namely: two-wayANOVA and Tukey's post-test. All analyzes will be performed with a significance level of 5%.