Introduction. Many studies focus on significant
differences in the expression of TLRs in periodontitis
and healthy controls. The biological function of TLRs
must have its toll on the host response to opportunistic
bacteria present in the oral cavity and in the gingival
sulcus/periodontal pocket. Aim of the study. To assess
TLR2, TLR4 and TLR9 expression in periodontal tissues
in patients with chronic and aggressive periodontitis.
Also to compare studied TLRs’ expression with clinical
parameters of periodontitis and evaluate clinical
periodontal status among patients with very low and
very high expression of examined TLRs. Material and
methods. The study included 62 patients aged from
17 to 70 years with chronic (CP-34) and aggressive
periodontitis (AgP-28) and 30 healthy controls. From
all participants a fragment of the gingival tissue was
taken to assess the expression of mRNA TLRs. Results.
All patients had significantly higher expression of
TLR4 and TLR9 compared to control. TLR9 expression
was significantly higher in the CP with regard to
AgP. There was no significant correlation between
the expression of TLRs and clinical variables in all
subjects with CP. Patients with AgP exhibited positive
correlations between the expression of all TLRs and the
presence of plaque. This group also showed positive
correlations between the expression of TLR4 and TLR9 and the severity of periodontitis. Substantially
higher values of all periodontal indices and a lower
number of teeth were reported in 15 individuals with
the highest expressions of TLR4. 15 patients with the
highest expressions of TLR9 showed significantly
higher rates only for plaque, severity and extent of
inflammation indices. Conclusions. Regardless of
the clinical diagnosis high TLR4 mRNA expression
in the gingival tissue is associated with the severity,
generalization and progression of periodontitis. High
TLR9 expression is associated mainly with plaque, and
could fulfill the protective function against progression
of periodontitis.