From the Guidelines
Yes, Streptococcus viridans can cause infective endocarditis following dental procedures, particularly in individuals with pre-existing heart conditions such as valve disease, congenital heart defects, or prosthetic heart valves. This occurs when these bacteria, which normally inhabit the mouth, enter the bloodstream during dental work that causes bleeding of the gums or oral tissues. The bacteria can then attach to damaged or abnormal heart valves or other cardiac structures.
Key Points to Consider
- The risk is highest with procedures involving manipulation of gingival tissue or perforation of oral mucosa 1.
- To prevent this potentially serious infection, antibiotic prophylaxis is recommended for high-risk patients before dental procedures, as outlined in the ACC/AHA 2008 guideline update on valvular heart disease 1.
- The standard regimen is amoxicillin 2g orally taken as a single dose 30-60 minutes before the procedure, with alternatives for patients allergic to penicillin including clindamycin 600mg, azithromycin or clarithromycin 500mg, or cephalexin 2g (if not severely allergic to penicillin) 1.
- Good oral hygiene is also crucial for prevention, as it reduces the bacterial load in the mouth and minimizes the risk of bacteremia during routine activities like brushing teeth.
High-Risk Groups
- Patients with a prosthetic heart valve or prosthetic material used for valve repair.
- Patients with a past history of infective endocarditis.
- Patients with cardiac valvulopathy after cardiac transplantation.
- Specific patients with congenital heart disease (CHD).
Prevention Strategies
- Antibiotic prophylaxis for high-risk patients before dental procedures.
- Good oral hygiene practices to reduce bacterial load and risk of bacteremia.
- Regular dental check-ups to identify and treat any oral health issues promptly. The current recommendations reflect a focus on the risk of adverse outcomes after infective endocarditis rather than the lifetime risk of acquisition of infective endocarditis, and emphasize the importance of maintaining optimal oral health and hygiene to reduce the incidence of bacteremia from daily activities 1.
From the Research
Strep Viridans and Endocarditis
- Strep viridans, also known as viridans group streptococci, are a type of bacteria that can be found in the mouth and are known to play a crucial role in the development of endocarditis, especially in patients with underlying cardiac conditions 2.
- Endocarditis is a rare but severe and often fatal inflammatory disease that affects the endocardial surface, native and prosthetic valves, or cardiac devices 2.
Dental Procedures and Endocarditis
- Dental procedures can lead to the transfer of bacteria from the oral cavity into the bloodstream, which can increase the risk of developing endocarditis 2, 3.
- However, the use of antibiotic prophylaxis before dental procedures to prevent endocarditis is a topic of ongoing debate, with some studies suggesting that it may not be effective in preventing endocarditis 3, 4.
Viridans Group Streptococci and Endocarditis
- Viridans group streptococci are responsible for 40-60% of endocarditis cases that occur on normal valves, especially in male patients over 45 years of age 5.
- A case report found that a 22-year-old female patient developed infective endocarditis with Streptococcus viridans associated with a fixed orthodontic appliance, highlighting the importance of maintaining good oral hygiene during orthodontic treatment 5.
Prevention of Endocarditis
- The American Heart Association recommends that antibiotic prophylaxis be used only for patients at highest risk of adverse outcome from endocarditis, and emphasizes the importance of good oral health and regular access to dental care for all patients 4.
- A study found that common high-street mouthwashes were effective in killing viridans group streptococci in vitro, highlighting the importance of maintaining good oral hygiene in patients at risk of endocarditis 6.