Estimation of volume density of interdental papilla components in patients with chronic periodontitis and interleukin‑6 (‑174G/C) gene polymorphisms

Abstract

Background: The association between interleukin‑6 (IL‑6) (‑174G/C) gene polymorphisms and

level of tissue breakdown and periodontal disease progression is unknown. The present study

investigated quantitative parameters of interdental papilla in chronic periodontitis (CP) patients

with IL‑6 (‑174G/C) gene polymorphisms.

Materials and Methods: Sixty gingival samples were studied. After determination of

IL‑6 (‑174G/C) gene polymorphisms using a tetra‑primer amplification refractory mutation

system‑polymerase chain reaction (T‑ARMS‑PCR) technique, 45 gingival tissue samples of CP patients

(GG and GC+CC genotypes) were considered as case groups. Fifteen control samples were also

collected from healthy individuals. After tissue processing, interdental gingival tissues were exhaustively

sectioned into 4 μm‑thick sections. Ten to thirteen sections were sampled by systematic uniform

random sampling and stained with Masson trichrome, and the volume density (Vv) of the gingival

components was estimated using Cavalier’s point counting method. Statistical analysis was performed

by Student t‑test to compare differences between groups. The significance level was set at P < 0.05.

Results: There were statistically significant differences in the Vv of epithelium, connective

tissue, collagenous and non‑collagenous matrix, and blood vessels between the control and CP

groups (P < 0.0001). There were no statistically significant differences in the Vv of epithelium,

connective tissue of gingiva, collagenous and non‑collagenous matrix, and blood vessels among GG,

GC, and CC genotypes in CP patients (P > 0.05).

Conclusion: Results of the current study showed that there was no association between

IL‑6 (‑174G/C) gene polymorphisms and quantitative parameters of interdental papilla in CP patients.

Key Words: Chronic periodontitis, genes, gingiva, interleukin‑6, polymorphism