Effect of CO2 laser and fluoride dentifrice on demineralization around orthodontic brackets bonded with an adhesive - an in situ study

Author(s)

Lívia Pagotto Rodrigues

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2013-02-28

Examining board members

Marinês Nobre dos Santos; Juliano Pelim Pessan; Erico Barbosa Lima

• Advisor: Marinês Nobre dos Santos

Abstract

The aim of this study was to verify whether the irradiation of carbon dioxide (CO2) laser with a wavelength of 10.6 ?m and density of 20.0 J/cm2 combined with the use of an orthodontic adhesive could reduce enamel demineralization around orthodontic brackets, subjected to a situation of high cariogenic challenge in the oral environment. For this, 80 human third molars retained were cut into 160 specimens of 5 x 5 x 2 mm, which were divided into the groups. During two phases of 14 days each, 20 volunteers (mean age 24 years) used a device intraoral palatal containing four specimens of human enamel, which were randomly divided into 4 groups: 1- Adhesive + Non Fluoride Toothpaste (NFT) (control), 2- CO2 Laser + Adhesive + Non Fluoride Toothpaste (NFT), 3- Adhesive + Fluoride Toothpaste (FT) and 4- CO2 Laser + Adhesive + Fluoride toothpaste. To simulate a high cariogenic challenge, volunteers dripped on the slabs a 20% sucrose solution eight times a day at predetermined times. After each phase, the biofilm around the brackets was collected and the fluoride concentration in the dry biofilm was analyzed, using an ion specific electrode. The mineral loss around orthodontic brackets was determined by cross-sectional microhardness measurement. The results of the fluoride concentration in dried biofilm were analyzed by Lilliefors and Kruskal-Wallis test followed by the Student Newman-Keuls test (? = 0.05) and the results of the mineral loss were analyzed by Lilliefors test followed by ANOVA. Regarding the fluoride concentration in the dry biofilm, the data showed a significant difference between groups 1 and 2 when compared to groups 3 and 4, and the groups 3 and 4 showed fluoride concentrations in the biofilm higher than those observed for groups 1 and 2. Under the experimental conditions employed in this study, the adhesive system was showed to be effective in reducing demineralization in situ around orthodontic brackets in a high cariogenic challenge situation. Thus, the presence or absence of CO2 laser and fluoride toothpaste showed to have no influence on the enamel mineral loss around orthodontic brackets (AU)

• FAPESP's process: 09/13551-0 - In situ evaluation of the effects of CO2 laser and fluoride toothpastes on enamel demineralization around orthodontic brackets
• Grantee: Lívia Pagotto Rodrigues
• Support Opportunities: Scholarships in Brazil - Master