Changes in the proteomic profile of acquired enamel pellicles formed in vivo for different times, after exposure to hydrochloric acid

• Autor(a) principal: Éven Akemi Taira
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://doi.org/10.11606/D.25.2017.tde-28062018-182748

Saliva it is an important factor against enamel and dentin damages. When the saliva enter in contact with the dental surface, results in a selective adsorption of salivary proteins, glycoproteins and lipids. This adsorption formed an organic free-bacterial film, which when formed in the enamel, is denominated acquired enamel pellicle. The presence of this proteins covering the enamel tissues, has the function of lubrication, buffering and remineralization capabilities, making it an important factor against dental erosion. The objective of this study was detected changes in the protein profile of acquired enamel pellicles (AEP) formed in vivo for different times, after application of hydrochloric acid (HCl). The experimental was realized in 12 consecutive days. On each day, nine subjects, (aged 18 to 35 years, non-smokers, with good general and oral health) were submitted to dental prophylaxis with pumice. After 3 or 120 min, time of formation of the acquired pellicle, the teeth were isolated with cotton rolls and, submitted for a 3 different procedures, one procedure of each day, 50 L of 0.1 M HCl (pH = 1.0), 0.01 M HCl (pH = 2.0) or deionized water were applied on the buccal surface of the teeth for 10 s. The application of HCl was in all teethes from the superior and lower arch, in vestibular surface. In sequence the AEP was collected using an electrode filter paper pre-soaked in 3% citric acid. This procedures was repeted for one more day. After protein extraction, the samples were submitted to reverse phase liquid chromatography coupled to mass spectrometry (nLC-ESI-MS/MS). Label-free quantification was performed (Protein Lynx Global Service software). A total of 180 proteins were successfully identified in the AEP samples. The number of identified proteins increased with the time of pellicle formation. Only 4 proteins were present in all the groups (isoforms of IgA, Serum Albumin and Statherin). The greatest number of proteins identified uniquely in one of the groups was obtained for the groups treated with HCl after 2 h of pellicle formation (~ 50 proteins). Conclusion: Proteins resistant to removal by HCl, such as Serum Albumin and Statherin, were identified even in the short-term AEP. In addition, 120-min pellicle present many proteins that are resistant to removal by HCl. This suggests an increase in the protection against intrinsic acids along the time of pellicle formation, which should be evaluated in future studies.