Free amino acid composition of saliva in patients with healthy periodontium and periodontitis

ObjectivesTo identify and compare the free amino acids in the saliva of periodontitis patients and healthy individuals and to assess their levels in different periodontal disease types.Materials and methodsThere were three groups: healthy individuals (control (C); n = 20), Stage III Grade B generalized periodontitis (GP-B; n = 20), and Stage III Grade C generalized periodontitis (GP-C; n = 20). Clinical periodontal parameters were measured. Amino acid analysis of the saliva was accomplished by liquid chromatography–mass spectrometry (LC MS/MS), taking the mean concentration.ResultsCitrulline and carnosine concentrations were significantly higher in patients with periodontitis than in the control group (p < 0.017). Methionine, glutamic acid, and arginine showed significantly higher concentrations in GP-C, whereas proline and tryptophan showed higher concentrations in the GP-B group (p < 0.017). There was a significant correlation between methionine, citrulline, arginine, and carnosine and clinical periodontal parameters.ConclusionsOur results demonstrate that periodontal status and disease type can result in variations in salivary amino acid (AA) content in correlation with clinical inflammatory signs. The significant correlation of methionine, citrulline, carnosine, and arginine with clinical parameters, regardless of systemic status, suggests that the levels of different salivary free AAs play roles in periodontitis.Clinical relevanceSalivary free AAs may be suggested as a potential diagnostic compound in patients with periodontitis.Clinical trial registrationClinicalTrials.gov NCT04642716