[Urea and ammonia in the saliva of patients with kidney diseases].

Blood and salivary urea, salivary ammonia were measured in 39 patients: 11 with chronic renal failure stage I-II (group 1), 12 with chronic renal failure stage III (group 2), control subjects without renal diseases (control group of 16 patients). The findings indicated higher levels of salivary urea in group 1 and 2. Salivary and blood urea concentrations correlated, the proportions being 68%, 40.8% and 61% for group 1, 2 and controls, respectively. The treatment of group 1 and 2 patients resulted in parallel changes in blood and salivary urea. In group 2 salivary ammonia reached the amount 5.7 mmol/l against control values 3.0 +/- 0.5 mmol/l. Salivary urea levels reflect the progression of renal dysfunction and may serve a diagnostic criterium.