Orogranulocyte peroxidase activity as a measure of inflammatory periodontal disease.

Benzidine dihydrochloride in the presence of dimethylsulfoxide reacts with myeloperoxidase contained within the granules of polymorphonuclear leukocytes obtained from the oral cavity. A blue meriquinoid oxidation product is formed in the presence of hydrogen peroxide, which can be extracted from the granules with a combination of methyl alcohol and dimethylsulfoxide. A stable yellow-brown pigment is formed which can be measured spectrophotometrically. The values are expressed in optical density units and correlate with the Orogranulocytic Migratory Rate units obtained by other means. Consequently, the spectrophotometric method is an additional non-subjective technique available for the evaluation, monitoring, and indexing the inflammatory periodontal disease.