Urease activity in saliva and plaque as endogenous protection against dental caries in institutionalized blind children

Background: Urease activity has been proposed to have a significant effect on dental caries, showing reduced caries activity with increased urease levels. Thus, the aim of the study was to evaluate the ureolytic activities of saliva and plaque in caries-active and caries-free institutionalized blind children. Materials and Methods: Fifty-two institutionalized blind children were divided into two equal groups using decayed, missing, and filled Teeth index as Group A – caries free and Group B – caries active. Urease activity was measured by collecting saliva and plaque samples from them. Children were refrained from any oral hygiene procedures during the 12 h preceding the sample collection. Urease enzyme activity was obtained by carrying out biochemical procedures. Mann–Whitney test was used to determine the statistical significance of the data. Results: In saliva, caries-free group had higher mean urease levels of 1.82 ± 0.497 as compared to caries-active group which had mean urease levels of 0.445 ± 0.304. In plaque, caries-active group had lower mean urease levels of 0.877 ± 0.942 as compared to caries-free group which had mean urease levels of 1.570 ± 0.918. The specific urease activity in saliva and plaque was significantly higher in individuals with low caries rates. Conclusion: Caries-free children had a higher ammonia generation activity by urease for both saliva and plaque samples than low caries-active children. High levels of alkali production in the oral environment were related to caries-free children.