Infection Theory In Periodontitis

For patients who are due to undergo heart valve replacement surgery, odontogenic infections and cariotic teeth are treated by dental surgeons prior to surgery. This removes the potential source of infection that could result in bacterial or infective endocarditis.

In the late 1980s a series of publications proposed a possible link between periodontitis and atherosclerosis. This could be considered as a return to the “focal infection theory” (Barnet, 2006).

The following two reports renewed interest in this century old hypothesis. Mattila KJ et al (1989) reported higher levels of caries and periodontitis, which are markers of oral infection and these were found to occur more frequently in patients with myocardial infarction than in the control group of patients. Syrajen et al (1989) observed poor oral health in patients who had a recent stroke compared with control group of patients who had not had a stroke. Following this there has been numerous publications on periodontitis and atherosclerosis (Lockhart et al, 2012).

Other epidemiological studies have suggested an association between chronic periodontitis and several other diseases such as respiratory diseases, diabetes, osteoporosis (Kuo et al, 2008), preterm low birth weight (Offenbacher et al, 1996), pancreatic cancer (Michaud et al, 2007), metabolic syndrome (Li et al, 2009) , chronic kidney disease (Craig , 2008) and rheumatoid arthritis (Bartoid et al, 2005).

It is beyond the scope of this dissertation to review the evidence for all these diseases and so this review will concentrate only on the relationship between oral health and atherosclerosis.

In order to better understand the published studies periodontal anatomy, oral pathogens and the development of atherosc...

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... also present in the gingival sulcus providing a nutrient rich environment for multiplication of different pathogenic bacteria.

The bacterial composition of the dental plaque varies according to the location. The oral cavity is not a single uniform environment. Different organisms are found in different sites (Lockhart et al, 2012). Bacteria are found on the mucosal surfaces, such as the cheek, tongue, gingival and also the mineralised surfaces of the tooth. The bacteria in these areas, which are far from the gingival crevice and periodontal pockets, are also important because the periodontal pathogens can spread and proliferate to reach these areas (Kolenbrander & London, 1993). The factors that favour different patterns of growth include surface receptors for bacterial adherence, oxygen tension, pH and redox potential. Bacterial composition is influenced by diet,