Salivary flow rate, total protein and pH in caries-free children and adolescents aged between 5 and 18 years

Abstract

Introduction. Data regarding salivary flow and the levels of salivary components in developmental age are scarce and not fully consistent. Aim. The aim of the study was to compare unstimulated mixed saliva flow rate, pH and total protein in children aged between 5 and 18 years to obtain information on the functional maturation of salivary glands during the developmental period. Material and methods. A total of 90 children and adolescents (both sexes) aged between 5 and 18 years were examined. All subjects were caries-free (ICDA II score zero). Unstimulated mixed saliva was sampled from all patients to assess pH, total protein and flow rate. The subjects were divided into age groups 5-6, 13-14 and 18 years. The study was approved by the Bioethics Committee of the University (No. Nr KB-335/2013). Results. Significantly lower salivary flow rates were observed in 5-6 year olds vs. 13-14 and 18-year-olds. In contrast, pH values were significantly higher in the youngest group compared to older age groups. Total protein was the lowest in 5-6 year olds, higher in 13-14 year olds and the highest at the age of 18 years (significant difference between age groups of 5-6 and 18 years). A decreasing trend in pH values and an increasing one in protein levels were observed between the age groups. Considering the entire group of subjects, a positive correlation between age and salivary flow rate and protein levels, and a negative correlation with pH were found. Moreover, pH and protein levels decreased with increasing salivary flow. Conclusions. Unstimulated mixed saliva flow rate and total protein increase, while pH levels decrease between the ages of 5 to 18 years.