Periodontitis ++

Periodontal germs

It has been proved by numerous scientific studies that a defined bacterial flora plays a part in the etiology of periodontal diseases and the failure of implants. The marker bacteria Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus and Treponema denticola are thought to play a key role, because the exotoxins produced by these bacteria are directly connected with the continuance of the inflammation and the increasing loss of supporting tissue. In order to introduce an antibiotic treatment of the bacteria which are often unavoidable during mechanical treatment, a microbiological diagnosis is necessary. Until now, this has usually been achieved by cultural methods. The detection of amplified bacterial DNA by reverse hybridization is a rapid, sensitive and highly specific alternative.

• The specific and sensitive detection of periodontal pathogenic marker bacteria in subgingival plaque samples allows risk patients to be quickly identified and gives important information for deciding on an efficient form of treatment.
• During periodontal treatment, the test can be used to document the treatment's success and to decide when the treatment should be ended.
• If the test is regularly carried out in recall, it is easier to recognize relapses early on and check for residual pockets.
• Before extensive prosthetic restoration, the test gives information on the risk of implant failure.
• The results can increase the patient's motivation and thus lead to improved oral hygiene.

In contrast to the cultural method of detection, this test, which is carried out on the nucleic acid level, is not dependant on the presence of living bacteria. This means simplified sample-taking and uncomplicated transport. With a detection limit of approx. 10⁴ bacteria, the PeriodontitisPlus test can be vastly superior to the cultural method.

It is advisable not to use the PeriodontitisPlus test for the first examination. The accompanying flora should initially be decreased by a first treatment step. The use of the PeriodontitisPlus test is always recommended when traditional treatment is unsuccessful.

DR4 and Periodontal Disease

A further important genomic factor influencing expression of periodontal disease is the HLA-constitution of the patient. In 1987 Katz and coworkers could show an association between HLA-DR4 and rapidly progressive periodontitis (RPP) when genotyping RPP-patients for HLA-A, HLA-B, HLA-C and HLA-D determinants. Regarding to 38% HLA-DR4 frequency in healthy controls 80% of RPP-patients were found to carry HLA-DR4. These data were confirmed by a further study of HLA-DR4 coding DRB1*04 alleles, in more detail. Bonfil et al. (1999) found a significant higher frequency (42%) of one of the DRB1 subtypes DRB1*0401, *0404, *0405 or *0408 in RPP-patients compared to 7% in healthy controls. It should be noted, that these subtypes are part of the "Shared Epitope" genotype that has been implicated in other inflammatory diseases like rheumatoid arthritis.

Note:
The AID PeriodontitisPlus test only detects the presence or absence of DR4 alleles in general. For a more detailed diagnosis of the DR4 subtypes please use the AID "Shared Epitope"- kit (RDB2035E).