285 - Nitrate Reductase Activity in Dental Plaque of Children and Adolescents

Purpose: Nitrate reductase (NR) of oral bacteria metabolizes dietary nitrate to nitrite, which is further reduced to nitric oxide by gut bacteria and absorbed into blood, thus lowering blood pressure and benefiting cardiovascular health. Limited information is available on NR activity in children. The null hypothesis is that there is a difference in NR activity in dental plaque between children with primary dentition and children with permanent dentition. This study evaluates and compares dental plaque NR activity between children with complete primary dentition and children with complete permanent dentition.

Methods: Forty-two healthy participants (3-15 years old) with primary (N=21) and permanent (N=21) dentitions were enrolled in the study according to specified criteria. One investigator completed dental examination for all participants and collected supragingival plaque from buccal and lingual surfaces of maxillary and mandibular first and second (primary/permanent) molars. Participants’ body mass index (BMI) were recorded. NR activity in plaque samples was assayed using the Griess reagent. Comparison of NR activity between the two groups was performed using the Mann Whiteney U-test.

Results: NR activity was detected in dental plaque samples of all participants. There was a statistically significant difference in NR activity between the primary dentition and permanent dentition groups (P <.001). BMI was found to be weakly associated with nitrate reductase activity (R=.384; P=0.027.).

Conclusion: While the health benefit of nitrate reductase in children’s oral cavity is not clear, NR activity was detected in children’s dental plaque and higher activity observed in children with permanent dentition. Studies regarding the association and contribution of specific microflora and NR activity are warranted.