Study of concentration and activity of carbonic anhydrase VI in saliva and biofilm of children in school age and its relation to tooth decay

Author(s)

Daniele de Cassia Rodrigues Picco

• Document type: Doctoral Thesis
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2016-02-18

Examining board members

Marinês Nobre dos Santos; Lidiany Karla Azevedo Rodrigues; Juliano Pelim Pessan; Alan Roger dos Santos Silva; Carolina Steiner Oliveira Alarcon

• Advisor: Marinês Nobre dos Santos

Abstract

The carbonic anhydrase VI (CA VI) is the main enzyme responsible for maintaining the buffer capacity in the oral environment. There are no reports in the literature on the relationship between the activity of this isoenzyme, pH, flow and buffering capacity and the prevalence of caries, and if the activity of CA VI can be employed as caries risk indicator. The objectives of this thesis were: 1) Conduct a systematic review of the literature 2) Determine the concentration and activity of CA VI in saliva and dental plaque of children with caries (C) and caries-free (CF) and the salivary flow, pH and buffering capacity; and 3) To investigate the relationship between these variables in saliva and dental plaque and tooth decay. For this, 74 students aged 7 to 9 years old were divided into 2 groups. It performed clinical examination, saliva collection and biofilm. The assays of the concentration of CA VI was performed by Elisa. The analysis of the CA VI activity by zymography. The salivary flow rate was expressed in ml/min. The salivary pH was determined by a portable pHmeter and the plaque pH with a selective electrode. The buffering capacity of saliva was measured eletrometrically. Data were subjected to Student's t test and Mann-Whitney, besides the Pearson and Spearman correlation analysis (? = 0.05). A bivariate analysis was performed in order to verify associations between the dependent and independent variables. In multivariate modeling, associations between the dependent and independent variables were expressed as odds ratios with 95% confidence intervals. The results showed significantly higher values of flow, salivar pH and buffering capacity in the CF group. The pH of the biofilm was also higher in the CF group. The concentration of CA VI in saliva and plaque were significantly higher in the LC group. The activity of CA VI was significantly higher in group C in saliva and plaque. There was a negative correlation between salivary buffering capacity and tooth decay. Moreover, a positive correlation was observed between the concentration and activity of CA VI in saliva and a negative correlation between the buffer capacity and isoenzyme activity in group C. In the CF group there was a negative correlation between pH and concentration of CA VI. A minor salivary flow and increased isoenzyme activity were significantly associated with caries. For dental plaque, it was observed negative correlation between activity and concentration of CA VI and between pH and activity of CA VI in the LC group. In the C group there was a negative correlation between pH and concentration of the CA VI. It concludes that the CA VI proved to be more active in saliva and dental plaque of children with active decay. Greater concentration of CA VI in saliva and dental plaque of caries-free children suggests that they are less exposed to cariogenic challenges, the system carbonate would be less active. The CA VI in saliva and dental plaque can be considered an anti-caries protein, as well as a biomarker for dental caries (AU)

• FAPESP's process: 12/02886-3 - Analysis of concentration and activity of carbonic anhydrase VI (CA VI) in saliva and dental plaque in children of school age.
• Grantee: Daniele de Cassia Rodrigues Picco
• Support Opportunities: Scholarships in Brazil - Doctorate