Endocarditis.
Endocarditis is a very serious-potentially lethal infection. It occurs when bacteria is introduced into the blood stream and infects the heart valves. If any of the valves are damaged, platelets and fibrin gather over the site - this is known as nonbacterial thrombotic endocarditis. It is these sterile formations that can become readily infected by bacteria that enter the body infective endocarditis.
This infection is affected by two major factors; bacteraemias and cardiac lesions where there is turbulent blood flow. The main type of bacterium involved with this infection is Viridans streptococci (found in large numbers in the mouth, especially abundant with poor oral hygiene) Strep. Mutans and S.sanguis - causing 50% of cases, and Staphylococcus aureus.
Viridans streptococci can be released into the bloodstream during dental treatment such as tooth extraction and scale and polishes. However it can also enter the blood stream during home oral care such as flossing and brushing. In the majority of cases this causes no harm and no infection of the heart occurs however there are a variety of factors that increase the chances of acquiring infective endocarditis;
The number of the bacteria that are entering the blood stream.
Valvular diseases and cardiovascular diseases that are suffered.
How well the bacteria adhere to the endocardium.
If prosthetic heart valves are present.
As it is very rare for the occurrence of infective endocarditis (1 in 3000 patients will acquire it from a tooth extraction) antibiotic protection is not necessary for most cases such as brushing. Obviously chances of infection are however increased in people suffering certain cardiovascular diseases High Risk include; chronic rheumatic heart disease, Prosthetic heart valves, and people who have previously suffered with infective endocarditis. The most common areas of infection in the heart are;
Mitral Valve 28-45%.
Aortic Valve 5-36%.
Tricuspid Valve 0-35%.
Someone suffering from infective endocarditis typically will not show symptoms until around 3 or 4 weeks after dental treatment. The symptoms include; mild fever, tiredness, breathlessness, joint pains, anaemia, blood in the urine and a skin rash. Eventually it will cause damage to the heart and vital organs and cause strokes leading to death in 30% of cases.
The main form of treatment for this disease is Penicillin and gentamicin, given
intravenously when the patient is admitted to hospital. If given quickly enough it will lessen any damage to the heart. If the patient has prosthetic valves, the valves need to be removed as quickly as possible and replaced.
When carrying out dental work, antibiotics should be given to patients who are at
intermediate or high risk of infective endocarditis. Ideally those patients that are at greater risk of contracting infective endocarditis should be given rigorous preventative dental care, so as to minimize the need for any invasive dental treatments.
Antibiotic cover is necessary with any tooth extraction, implant surgery, probing, scaling, intraligamental local anaesthesia and endodontics beyond the root apex. The two normal options for cover include Amoxicillin and Clindamycin, both given one hour before treatment. It is vital that the patient who is at risk of infective endocarditis is told to report back immediately if they suffer any symptoms which can appear as late as two months after treatment. If multiple treatments are required for a susceptible patient, then they should be at intervals of nine to fourteen days, this is necessary so as the bacteria does not become resistant to the antibiotics.
As a dentist is it vital to review medical history with a patient every time they are seen. However, patients do not always remember their medication or diseases that they suffer from. There are also many people that do not even know that they are suffering with a heart condition. Therefore, it is always going to be possible for a patient to develop infective endocarditis even with a safe medical history. In fact 40% of cases of infective endocarditis are from patients with unsuspected defects or even a healthy heart!