Reyes, EvelynMartin, JavierMoncada, GustavoNeira, MiguelPalma, PatriciaGordan, ValeriaOyarzo, Juan FernandoYévenes, Ismael2016-07-042016-07-042014J. Appl. Oral Sci. vol.22 no.3 Bauru May./June 20141678-7757http://dx.doi.org/10.1590/1678-775720130591http://repositorio.unab.cl/xmlui/handle/ria/947Indexación: Web of Science; Scielo.Objectives: This study investigated the relationship between urease and arginine deiminase system (ADS) activities and dental caries through a cross-sectional study. Material and Methods: Urease and ADS activities were measured in saliva and plaque samples from 10 caries-free subjects and 13 caries-active. Urease activity was obtained from the ammonia produced by incubation of plaque and saliva samples in urea. ADS activity was obtained from the ammonia generated by the arginine-HCl and Tris-maleate buffer. Specific activity was defined as micromoles of ammonia per minute per milligram of protein. Shapiro-Wilk statistical test was used to analyze the distribution of the data, and Mann-Whitney test was used to determine the significance of the data. Results: The specific urease activity in saliva and plaque was significantly higher in individuals with low DMFT scores. ADS activity in saliva (6.050 vs 1.350, p=0.0154) and plaque (8.830 vs 1.210, p=0.025) was also higher in individuals with low DMFT scores. Conclusions: Caries-free subjects had a higher ammonia generation activity by urease and arginine deiminase system for both saliva and plaque samples than low caries-active subjects. High levels of alkali production in oral environment were related to caries-free subjects.enAlkaliArginineDental plaqueSalivaUreaseDental cariesArtículo