Salivary concentration of free LL-37 in edentulism, chronic periodontitis and healthy periodontium

ObjectiveThe antimicrobial peptide LL-37, a component of innate immunity, has an important role in maintaining oral health. This study aimed to investigate the concentration of free LL-37 in whole saliva of periodontally healthy, edentulous and chronic periodontitis subjects.DesignUnstimulated whole saliva was sampled from 154 subjects (76 periodontally healthy, 20 edentulous, and 58 subjects with chronic periodontitis). All participants were in good general health. The salivary LL-37 was determined by ELISA.ResultsThe median salivary concentrations of free LL-37 were 30.5, 22.5, and 1.8 ng/ml for the healthy, the chronic periodontitis and the edentulous group, respectively. The differences in concentration between the edentulous and the others were statistically significant (Mann–Whitney test, p < 0.001). In the healthy subjects, women displayed significantly higher peptide concentrations compared to men (Mann–Whitney test, p < 0.05). The intra-subject variation in LL-37 concentration was wider for the healthy (range 0.75–285 ng/ml) and chronic periodontitis patients (range 1–207 ng/ml) than for the edentulous subjects (range 0.15–4.4 ng/ml).ConclusionsThe present findings show that edentulism correlates with a substantial decrease in salivary levels of free LL-37, thus indicating the considerable contribution of the gingival tissues in the secretion of the peptide in the oral environment.