The case for bacterial specificity in periodontal disease was made using the bacterial cultural approach, which relies on the ability to grow, under an anaerobic atmosphere, the germs on agar media containing an abundant supply of nutrients. In recent years molecular techniques involving DNA probes have confirmed the importance of anaerobic species such as P. gingivalis, T. denticola and T. forsythensis (shorter names for the germs cited in the preceding paragraph). But these are laboratory procedures and are not useful in the dental office, except possibly as a means of guidance in cases that prove to be non-responsive to treatment.

Microcsopic Examination of Plaques. The germs in the dental plaque can be seen under the microscope, as Leeuvenhoek described in the 17^th century when inventing the light microscope. One group of germs, known as spirochetes, look and move like thin worms when watched through a microscope. We and others have used a microscopic examination of the plaque to identify spirochetes, including T. denticola. as being almost always present, or  at high levels in the plaques found when on periodontally diseased teeth. Also prominent in plaques removed from sites of inflammation are white blood cells. Paul Keyes in the late 1970s reignited interest in the chair-side microscope as a means of diagnosing, and monitoring the treatment of periodontal disease when he added a television camera to the microscope. This allowed both clinicians and patients to see the frantic germ movement innate to an infected plaque on a TV monitor, and then to see it “quiet down” after treatment.

The BANA test. Taxonomic studies of the germs found in diseased plaques revealed that P. gingivalis, T. denticola and T. forsythensis possessed an enzyme that is capable of hydrolyzing the synthetic substrate benzoyl-DL-arginine-naphthylamide, or BANA.  Over 60 other types of germs did not have the BANA enzyme, indicating that if we could find BANA activity in dental plaques, this might be a simple way of diagnosing an anaerobic periodontal infection. Subsequently we developed the BANA test to identify these germs in plaque samples at chair-side, and showed that the BANA test is as reliable as DNA probes in identifying these bacteria.  We diagnose an anaerobic periodontal infection, when there is a BANA positive reaction in at least three of four plaque samples taken from teeth with the most inflamed clinical sites. The BANA test is available to professionals from OraTec Corp (www.oratec.net).

BIOSKETCHES | EDUCATION | PUBLICATIONS | LINKS | QUESTIONS | EMAIL | HOME