Etiopathology of periodontitis is complex and various risk factors are known :
- Bacterial factors: major risk factor. Although the presence of periodontopathogen
bacteria is necessary for the onset of periodontitis, these microorganisms are not
sufficient for progression of all periodontal disease.
- Immune factor: host immune response modulates the disease evolution to destruction or
recovery. The most studied cytokine in periodontology is IL-1 that induces various
immune reactions and bone resorption directly or indirectly through the stimulation of
prostaglandin E2 (PGE2) release. PGE2 activates the matrix metalloproteinases that are
responsible of the degradation of bone extracellular matrix.
Cytokine production, especially TNFα, IL-1β, IL-6 and IL-8, by some immune cells is modulated
by new identified molecules such as Triggering Receptor Expressed on Myeloid cells (TREM)
whose role in periodontitis is unknown.
The purpose of this study is to compare concentrations of soluble TREM-1 and TREM-2 markers
in infected sites and in healthy sites in patients affected by periodontitis.
Other purposes are
1. Comparison of soluble TREM-1 and TREM-2 concentrations in healthy sites in patients
affected by periodontitis and in healthy patients
2. Comparison of soluble TREM-1 and TREM-2 concentrations before and after etiologic
3. Estimation of the correlation between soluble TREM-1 and TREM-2 concentrations and
clinical signs of periodontitis
4. Description of soluble TREM-1/TREM-2 ratio before and after etiologic treatment
5. Description of presence of some bacteria in sites analyzed for soluble TREM-1 and TREM-2
6. Search for the most observed bacteria in presence of high concentrations of soluble
TREM-1 and TREM-2 before and after etiologic treatment
7. Evaluation of the impact of psychological stress measured through salivary cortisol
level in saliva on TREM-1 and -2 expression
8. Evaluation of the impact of psychological stress through stress and anxiety
auto-questionnaires (Spielberger and Cohen) on soluble TREM-1 and TREM-2 concentrations
in crevicular fluid of healthy and pathologic teeth.