Device for diagnosing periodontal disease

Abstract

A colorimetric assay system for diagnosing periodontal disease utilizes a chromogenic test substance for measuring proteolytic activity in a specimen such as subgingival plaque which may contain suspected periodontopathogenic bacteria. The chromogenic test substance comprises a peptide substrate which is hydrolyzable by proteolytic enzymes in the plaque specimen to release a chromophore. Detection of a color change in the test substance indicates whether such proteolytic activity is present. In a specific illustrative embodiment, the chromogenic test substance comprises N-benzoyl-DL-arginine-2-naphthylamide (BANA) or benzoyl-DL-arginine-p-nitroanilide (BAPNA). In the case of BANA, for example, the chromophore, .beta.-naphthylamide, is detected by the addition of a color developer, such as fast garnet. The development of a red-orange color is interpreted to indicate the presence of periodontal disease associated with anaerobic periodontopathogens, such as B. gingivalis, T. denticola, and B. forsythus, and the development of a yellow color is interpreted to indicate the absence of periodontal disease. The assay method can be carried out with a device having a first region containing on a support carrier a chromogenic test substance hydrolyzable by proteolytic enzymes of periodontopathogenic organisms to release a chromophore and a second region containing on a support carrier a color developer. The first and second regions are arranged so that they can be brought into superposition. The chromophore is released if the periodontopathogenic organisms exceed about 5.times.10.sup.5 colony units.

Dependencies are inferred from the claim text.