Differences in saliva composition in patients with gastroesophageal reflux disease with and without dental erosion: proteomic study

• Grant number: 17/21709-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2017
• End date: November 30, 2018
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: Rebeca Do Vale Placa
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

Dental erosion is loss of dental hard tissue provoked by non-bacterial acids. These acids can have extrinsic (diet, mainly) or intrinsic (host) origin. A common gastrointestinal disease that contributes to dental erosion is gastroesophageal reflux disease (GERD). About 24-48% of patients with GERD have dental erosion caused by the low pH (1 to 3) of regurgitated gastric contents. The objective of this study is to compare the protein profile of unstimulated and stimulated saliva among patients with GERD and erosive lesions, patients with GERD without erosive lesions and control patients (without GERD and erosive lesions). A total of 27 volunteers will be divided into 3 groups: (a) patients with GERD and dental erosion (BEWE e 9 or grade 3 in the upper anterior sextant (with all incisors affected); patients with GERD without dental erosion (BEWE =0); C) control patients (without GERD and BEWE = 0). The patients (n = 9 per group) will initially be submitted to non-stimulated saliva collection for 5 min. After this time the collected saliva will be stored. The stimulated saliva will be collected while chewing parafilm for 5 min. After this time, saliva will be stored. After protein extraction, samples will be submitted to reverse phase liquid chromatography coupled to mass spectrometry (nLC-ESI-MS/MS). Label-free proteomic quantification will be performed using Protein Lynx Global Service(PLGS) software considering 1-p>0.95 and p<0.05 for upregulated and downregulated proteins, respectively. (AU)