Periodontal disease is a chronic infection of the gums characterised by a loss of attachment between the tooth and bone, and bone loss. C-reactive protein (CRP) elevation is a part of the acute phase response to acute and chronic inflammation. Many epidemiological studies have shown that serum CRP levels were elevated in patients with chronic periodontitis. CRP levels increase to hundreds of μg/ml within hours following infection. It out-performs erythrocyte sedimentation rate (ESR) in terms of responsiveness and specificity for inflammation. While CRP elevation is suggestive of inflammation or infection in the appropriate clinical context, it can also occur with obesity and renal dysfunction. Conversely, a lack of CRP elevation in inflammation may be seen with hepatic failure, as well as during flares of conditions such as systemic lupus erythematosus.