Método para avaliação clínica da capacidade tamponante salivar A method for the clinical evaluation of salivary buffer capacity

O presente estudo teve por objetivo o desenvolvimento e a padronização de um método colorimétrico para avaliar a capacidade tamponante salivar média de nossa população. As amostras de saliva estimulada foram tituladas sem eliminação do CO2. Estudos foram realizados para verificar a influência da perda de CO2 das amostras durante o período necessário para a realização das titulações e para a padronização do tempo de leitura do pH. A partir das titulações realizadas nas amostras de saliva de 206 indivíduos de ambos os sexos na faixa etária de 5 a 50 anos, na proporção de 0,77:1:0,44, respectivamente para crianças, jovens e adultos, foram feitas as distribuições de freqüências dos casos, a determinação média do pH inicial, do pKa, microequivalentes relativos ao final da titulação, pH final da titulação e uma estimativa da porcentagem da saliva titulada em pH 5. Com base nestas variáveis foi estabelecida uma classificação dos indivíduos quanto à capacidade tamponante. Análise dos resultados utilizando-se 11, 12 ou 13 microequivalentes de H+/ml indicam que o valor de 11 microequivalentes/ml de saliva é o mais apropriado para a avaliação da capacidade tamponante salivar em nossa população.<br>The present study aimed to develop and standardize a colorimetric method for assessing salivary buffer capacity adapted to the features of the Brazilian population. Samples of stimulated saliva were titrated without CO2 elimination. The assessment was carried out to study the influence of the loss of CO2 from the samples during the few minutes necessary for titration, and to standardize the instants for measuring pH. Saliva samples were titrated from 206 individuals from both genders, between 5 and 50 years of age, and in a proportion of 0.77 : 1 : 0.44, respectively of children, youngsters, and adults. Case frequency distribution; determination of average values of initial pH, pKa, µ equivalents related to titration end point and final pH; and estimate of the percentage of saliva titrated at a pH of 5.0 were calculated based on the data collected. The results were used to classify individuals according to their salivary buffer capacity by colorimetric pH determinations using 11,12, and 13 µ equivalents of H+/ml saliva, and were compared to case frequency distribution obtained from saliva titration data. The results indicate that 11 µ equivalents H+/ml of saliva is the most appropriate for clinically evaluating the salivary buffer capacity of our population

Salivary parameters and teeth erosions in patients with gastroesophageal reflux disease

CONTEXT: In the gastroesophageal reflux disease (GERD), a highly prevalent digestive disorder, gastric content may return to the esophagus and reach the mouth, thus leading to a small number of carious lesions and high incidence of dental erosion. Since saliva plays a major role in oral homeostasis, evaluating salivary parameters is necessary in attempting to explain such outcome. OBJECTIVES: This study aimed at analyzing salivary parameters (salivary flow, pH and buffering capacity), bacterial count, caries index and dental erosion in patients with GERD. MATERIALS: Sixty patients were studied, and of these, 30 had GERD (group 1), and 30 were controls (group 2). Gastroesophageal reflux disease diagnosis confirmation was achieved by means of endoscopy, manometry and pH metric esophageal monitoring. The above mentioned salivary parameters were evaluated in patients from groups 1 and 2. RESULTS: The number of erosions in patients with GERD (group 1) was larger than in controls (P<0.001). The number of carious teeth was smaller in group 1 than in group 2 (P<0.001). Salivary flow (non-stimulated and stimulated) and pH did not show differences between the 2 groups (P = 0.49; P = 0.80 and P = 0.85, respectively). Salivary buffering capacity in patients with GERD showed lower values in controls (P = 0.018). The number of bacteria (Lactobacilli and Streptococci) was smaller in patients with gastroesophageal reflux disease than in controls (P = 0.0067 and P = 0.0017, respectively). CONCLUSION: It was concluded that the large number of erosions must be a result of GERD patients reduced salivary buffering capacity. The reduced number of caries of patients in group 1 can be explained by the low prevalence of bacteria (Lactobacilli and Streptococci), observed in the saliva of patients with chronic reflux