Objectives: 

Dental decay is a bacterial infectious disease, which results into irreversible localized destruction of dental structures. The aim was to investigate some salivary parameters involved in tooth decay.

Materials: 

There were investigated some salivary factors involved in tooth decay in a group of students aged 20-23 years (35 cases). The subjects were clinically investigated and was noted DMF index (D- decayed, M- missing, F- filled). The students provided stimulated saliva samples before and immediately (5 minutes) after a stressful condition represented by a difficult exam. There were noted salivary volume and salivary flow/minute. The buffer capacity was determined with Dentobuff® Strip kit from VIVA-CARE. From salivary sediment were determined the number of leukocytes, epithelial cells and cell viability with tripan blue dye (under microscope the cells which exclude the dye are viable) expressed as percent. To compare the results t Student test was performed. Were compared the mean values of investigated parameters before and after the exam.

Results: 

The salivary volume (4.1±1.02ml), salivary flow (0.82±0.2 ml/min) and pH (7.1±0.54) were decreased before the exam, probable due to sympathetic stimulation associated with the increase of salivary mucus. The increased salivary flow (1±0.49 ml/min) after the exam was correlated with increased pH (7.6±0.54). The leukocytes number slightly decreased after the exam. The increased number of epithelial cells after the exam (from 128±61.4 /mm3 to 142±14.6 /mm3) was correlated with the decrease of cellular viability (from 86±10.83% to 81.6±10.96%). This can induce a decrease in the function of protective barrier represented by oral epithelium.

Conclusions: 

The increase of salivary flow, pH and cellular viability is a sign that the body responds with a defense reaction to stress. But prolonged stress can produce a decrease of body defense which can exacerbate cariogenic bacterial virulence in oral cavity.