Effect of acidulated phosphate fluoride application on the protein composition of salivary enamel pellicle

Author(s)

Nádia Masson

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2012-12-14

Examining board members

Adriana Franco Paes Leme; Cinthia Pereira Machado Tabchoury; Severino Matias de Alencar

• Advisor: Adriana Franco Paes Leme

Abstract

The acquired pellicle is a protein film resulting from the selective adsorption of proteins present in whole saliva onto tooth surfaces. Because of its contact with enamel surfaces, the enamel pellicle plays an important role in the initial stages of plaque formation by modulating bacterial attachment. High concentrated fluoride product treatment of enamel has been reported to result in the formation of a layer of a CaF2-like material ("CaF2") on the enamel surface. Protein adsorption to enamel is a specific process dependent on the nature of the surface, and little is known about the influence of this "CaF2" layer on pellicle composition. The purpose of this investigation was to gain further insights into the in vitro pellicle components when APF application is performed. Bovine enamel blocks were randomly divided in 3 groups. Each block was exposed to distilled water (negative control), or phosphoric acid (active control - 0.1 M H3PO4 pH 3.5) or acidulated phosphate fluoride (APF) (0.5 M NaF in 0.1 M H3PO4 pH 3.5) solution for 4 minutes. Blocks were then washed, dried and immersed in human saliva for 2 hours for enamel pellicle formation. AEP from each group was collected, subjected to trypsin digestion protocol and the peptides generated were analyzed by reverse-phase liquid chromatography coupled with nanoelectrospray ionization in a LTQ Velos Orbitrap mass spectrometer. After analyses of the data by Proteome Discoverer e ScaffoldQ+ programs 56 proteins were identified. Each treatment group presented a similar amount of total identified protein and 17.8% of total proteins were present in all four groups. Twelve proteins were exclusively in the group treated with water, 11 proteins were exclusively in the group treated with phosphoric acid and another 12 proteins were only present in the discs treated with APF solution. Relative proteomic quantification showed that the abundance of some proteins decreases with APF application, such as histatin-1. However, the concentration of S100 - A9, confirmed by immunoblotting analyses, increases when enamel surface was treated with APF solution. These data suggest that the modification caused on enamel surface by APF application influences the composition of AEP and may have an impact on initial bacterial attachment (AU)

• FAPESP's process: 09/12368-7 - Proteomic analysis of acquired enamel/dentine pellicle treated with fluoride
• Grantee: Nádia Masson
• Support Opportunities: Scholarships in Brazil - Master