Reporter Volume 25, No.26 April 28, 1994

DENTAL SCHOOL
Test to find antigens effective, UB study shows
A five-minute test designed for use in the dentist's office to
determine the presence of antigens from three major bacteria found in
localized juvenile periodontitis gets high marks for accuracy,
according to a study by researchers at  UB.
	The EVALUSITE Periodontal Test also could be used to detect
bacteria prevalent in the adult form of the disease, says Sara G.
Grossi, assistant professor of oral biology and principal investigator
on the study.
	Grossi presented the findings of her research on the EVALUSITE
Test March 11 at the general meeting of the International Association
for Dental Research in Seattle.
	The EVALUSITE Test measures the antigens for Actinomyces
actinomycetemcomitans, Porphyromonas gingivalis and Prevotella
intermedia, the three major bacteria present in localized juvenile
periodontitis. EVALUSITE is the only chairside test available. The
presence of antigens previously was determined through culture.
	In the UB study, measurements of the pocket depth at 16 gum
sites and samples of subgingival plaque were take from 16 patients
ages 10 to 25.
	Sites with a pocket depth of 5 mm or greater were labeled
diseased; those of 4 mm or less were labeled healthy.  Loss of
attachment (LOA) of tooth-supporting tissue also was measured, with a
LOA of 3 mm or less rated as healthy and a LOA of 4 mm or greater
labeled diseased.
	 Researchers found a marked difference in the presence of
antigens for the three bacteria in healthy vs. diseased areas when
using the EVALUSITE Test. The test showed that the higher the numbers
for the bacterial antigens, the deeper the pockets and the greater the
LOA.
	The prevalence of A. actinomycetemcomitans was found to be
12.5 percent for diseased areas compared to 3.4 percent for healthy
areas. The incidence of P. gingivalis was 27.5 percent for diseased
areas compared to 11.8 percent in healthy areas. And the prevalence of
P. intermedia was 37.5 percent for diseased areas vs. 14.3 percent for
healthy.
	The EVALUSITE Test is currently marketed in Canada and some
European countries, but is not yet available in the United States. It
has been used in more than 300 patients, with more than 4,000 samples
being collected.
	In addition to Grossi, other members of the research team are
Brian Snyder, research scientist, and Carol Ryerson,  director of
clinical trials, both at Eastman Kodak Co.; Robert Dunford, a UB
biostatistician, and Robert J. Genco, chair and distinguished
professor in the UB Department of Oral Biology. The study was funded
by the U.S. Public Health Service and Eastman Kodak Co.
Selective antibiotics can save dental implants
Penicillin G and amoxicillin appear more effective than either
tetracycline or erythromycin in preventing and treating bacterial
infections that can undermine dental implants, a team of Italian and
UB researchers has found.
	More than a dozen antibiotics are used routinely as adjunct
treatment for bacterial infections that destroy bone and lead to tooth
loss. These same microorganisms are related to infection of bone
surrounding dental implants. Often the only treatment is to remove the
implant.
	But according to the findings of the UB study presented March
12 at the International Association for Dental Research meeting,
selective antibiotic therapy, tailored to the specific organisms
cultured from tissue surrounding the implants, can help preserve them.
	In the study, two subgingival samples from each of 19 failed
implants from 13 patients were cultured in the laboratory. Three
bacteria were found to have contributed to the implant failures:
Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium
nucleatum, all of which are associated with periodontal disease.
	Penicillin G and amoxicillin, as well as
amoxicillin-clavulanate and amoxicillin-metronidazole, were found to
be significantly more effective against the three bacteria than
tetracycline, erythromycin, metronidazole or clindamycin.
	But because penicillin G and amoxicillin also are commonly
used for non-oral infections, they should not be used continually or
indiscriminately since they could interfere with treatment of systemic
infections, warned Sebastiano Andreana, clinical investigator in the
UB Department of Oral Biology who presented the study results.
	"Implant recipients cannot be given the medications as a
long-term preventive measure," Andreana emphasized. "But with regular
follow-up and proper oral hygiene, dentists can begin the therapy on a
short-term basis to increase the longevity of the implants."
	Ludovico Sbordone, professor and director of the Dental School
of Reggio Calabria in Italy, headed the study.