Introduction: TLR4 act as the principal sensors of innate immune responses, especially for the Lipopolysaccharide leading to the unregulated inflammatory response, which would otherwise cause tissue destruction. This is regulated by Radio protective 105 (RP105) a TLR4 protein homologue.

Objective: To investigate the expression of RP105 in chronic and aggressive periodontitis patients.

Material and methods: 60 subjects, 20 periodontally healthy controls, 20 chronic periodontitis and 20 aggressive periodontitis were included. Gingival index, oral hygiene index–simplified, probing depth and clinical attachment loss were recorded followed by immunohistochemical evaluation of RP105 expression in the gingival tissue samples and the results were statistically evaluated through 1–way ANOVA and Mann–Whitney U test.

Results: Significant expression of RP105 in gingival connective tissue of three groups (P=0.0000*). The expression of RP105 in gingival connective tissue of healthy group was higher in comparison to chronic periodontitis subjects and was statistically significant (P = 0.0082*).

Conclusion: The present study demonstrated weak RP105 expression in the gingival epithelium owing to the fact that RP105 is an anti–inflammatory marker.