Salivary Biomarkers in a Biofilm Overgrowth Model

Abstract

Background The purpose of this study was to determine whether baseline salivary inflammatory biomarkers could discriminate between different clinical levels of disease and/or predict clinical progression over a 3-week stent-induced biofilm overgrowth (SIBO) period. Materials and Methods 168 participants were enrolled in a 21-day experimental gingivitis investigation and grouped according to clinical measures of periodontal status of health and diseased individuals representing each of five biofilm gingival interface (BGI) periodontal groups (H, G, P1, P2, P3). Stents were used to prevent plaque removal during brushing over one maxillary and one mandibular posterior dental sextant for 21 days. Clinical periodontal parameters and unstimulated saliva were collected at screening, baseline, and each week during SIBO. Saliva samples were assessed for levels of 13 different biomarkers by multiplex immunoassay. Results Higher salivary levels of interleukin (IL)-1β, matrix metalloproteinase (MMP)-3, MMP-8, MMP-9, and neutrophil gelatinase-associated lipocalin (NGAL) were found in diseased groups compared to healthy at baseline. Conversely, higher IL-1 receptor antagonist (ra) levels were found in healthy patients at baseline. In addition, during SIBO MMP-1, tissue inhibitor of metalloproteinase (TIMP)-1, and TIMP-2 levels increased across all participant groups. A stepwise linear regression model using all salivary biomarkers demonstrated that at baseline increased IL-1ra (p=0.0044) and IL-6 (p=0.0093) were the two best predictors of change in probing depths during SIBO. Conclusions In summary, this investigation supports salivary levels of IL-1ra and IL-6 as potential indicators for significant probing depth changes during induced gingival inflammation. In addition, participants from BGI-P3 group (severe periodontitis) demonstrated elevated baseline levels of IL-1β, MMP-3, MMP-8, MMP-9, and NGAL compared to other study groups strengthening the relevance of participant's biological phenotype on salivary biomarkers expression

Impact of smoking on experimental gingivitis. A clinical, microbiological and immunological prospective study

“…VPI and GBI were assessed at baseline and at 21 d of undisturbed biofilm accumulation (experimental gingivitis phase) and again 7 d after oral hygiene was resumed in the experimental quadrants (resolution phase). The increases in the biofilm mass (plaque index) and in the gingival index, found in the current investigation, are expected during experimental gingivitis assays, as reported by others . In the present study, VPI scores did not differ significantly between the two groups at any time point.…”

Novel biomarkers of periodontitis and/or obesity in saliva—An exploratory analysis

“…20 Another recent investigation using an experimental gingivitis model in 168 participants reported IL-1ra (in addition to IL-6) to be a potential indicator for pocket depth increase in these participants. 21 Contrary to our result on the negative correlation between periodontitis severity and sCD40L salivary levels, a recent case-control study reported a positive correlation between this marker in GCF and periodontitis severity. 22 To our knowledge, there are no published studies on the correlation of periodontal severity and the expression of the other two biomarkers tested (i.e.…”

Targeted Proteomics Guided by Label-free Quantitative Proteome Analysis in Saliva Reveal Transition Signatures from Health to Periodontal Disease

“…The analysis by STRING reveled that CLUS was one of the center nodes strongly over-connected with RAP1A, MMP-9, and several SERPIN family proteins. MMP-9 has a well-established role in disease, demonstrated also by the higher salivary levels of MMP-9 in periodontitis compared with health (74,75). RAP1A, a unique member of the Ras G protein family, is known to regulate several proteins controling diverse biological functions (76), including inflammation (77) and regulation of osteoclast function and bone resorption (78), consistent with the histopathological traits of periodontitis.…”