24 May 2023

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Oral hygiene and bacterial endocarditis

Lara Figini

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Infectious bacterial endocarditis (IE), typically encountered as heart valve infection, is rare in the general population but associated with high morbidity and mortality.

It was first suggested more than 100 years ago that oral bacteremia could cause IE.

In 1955, the first American Heart Association (AHA) guidelines on the prevention of IE recommended that patients at increased risk of IE receive prophylactic antibiotics before undertaking invasive dental procedures.

However, in 2007, the AHA reversed this recommendation for those considered to be at moderate risk for complications from IE, a cohort comprising approximately 90% of people with valvular heart disease, recommending antibiotic prophylaxis only for high-risk individuals undergoing IE.

These recommendations were maintained in the 2021 Cardiology Guidelines from the AHA/American College. Most of the dental plaque involves streptococci (for example, S. mitis) and under healthy conditions the gingival crevice around the teeth is lined with a thin layer of highly permeable non-keratinized epithelium which separates potentially pathogenic organisms from the general circulation.

The accumulation of dental plaque and tartar results in bacterial growth, gingival inflammation, ulceration and increased permeability of the crevicular epithelium which probably lead to an increased frequency of bacteremia.

There is growing evidence in the literature that frequent bacteremia due to plaque and tartar is probably associated with an increased risk of IE.

Materials and methods

In a case control study published in March 2023 in Oral Surgery Oral Medicine Oral Pathology Oral Radiology, the authors determined whether oral hygiene was associated with infective endocarditis (IE) among individuals at moderate risk for IE. In this study, hygiene was investigated in hospitalized patients with IE (cases) as compared with outpatients with valvular heart disease but without IE (controls).

The primary endpoint was the mean dental calculus index. Secondary objectives have included other oral hygiene measures and periodontal disease (e.g., dental plaque, gingivitis). Blood culture categorization of bacterial species was also performed.

Results

The 62 participants in the case group had a mean dental tartar index 53% higher than the 119 participants in the control group (0.84, 0.55, respectively; difference = 0.29, 95% CI: 0.11, 0.48; p = 0.002) and 26% mean index of major dental plaque (0.88, 0.70, respectively; difference = 0.18, 95% CI: 0.01, 0.36; p = 0.043).

Overall, cases reported fewer dental and dental hygiene visits (p = 0.013) and fewer dental visits in the 12 weeks prior to enrollment in the study than controls (p = 0.007).

Common oral bacteria were identified from blood cultures in 27 of 62 cases (44%).

Conclusions

From the data of this study, researchers concluded that in people at risk of bacterial endocarditis, it is possible to reduce the potential sources of bacterial endocarditis related to it by maintaining optimal oral health through regular professional dental care and procedures constant and correct home oral hygiene.

For more information: "Oral hygiene and infective endocarditis: a case control study."