Young Bui
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 EFORE
TREATING patients, we should always take a good medical history.
Always go over the questions with the patients to make certain that they
understand the technical terms. Be sure to ask whether they have
had a disease or medical problem that is not listed on the history form.
Investigate further about systemic diseases that they mark and ask what
medications they are taking. Certain patients will need to be pre-medicated
before treatment to prevent systemic bacterial endocarditis (SBE).
Endocarditis occurs when bacteria enter the bloodstream and infect
damaged endocardium or endothelial tissue located near high-flow shunts.
The dentist’s goal is to prevent endocarditis from occurring in susceptible
dental patients. Any dental procedure that causes injury to the soft
tissue or bone, resulting in bleeding, can produce a transient bacteremia.
Below is a list of the frequency of bacteremia associated with various
dental procedures and oral manipulations based on Bender in 1984 and Pallasch
in 1989.
| Periodontal surgery |
88 % |
| Extractions |
51-85 % |
| Periodontal scaling |
8-80 % |
| Chewing |
17-51 % |
| Dental prophylaxis |
0-40 % |
| Toothbrushing |
0-40 % |
| Endodontic therapy (non-vital) |
0 % |
Consider antibiotic prophylaxis (AP) for dental
work to minimize effects of bacteremia. Besides the usual heart conditions
that require AP, such as rheumatic fever, heart murmur, mitral valve prolapse
with regurgitation, and congenital heart disease, many other conditions
that require prophylaxis may be overlooked. One example is HIV.
We seldom ask patients if they are HIV+ because we don’t want to embarrass
patients or because we take universal precautions against HIV. Not
asking may be harmful to the patient. A patient who contracted HIV
from sharing needles is very likely to have had SBE previously, due to
injecting bacteria directly into the bloodstream. Infective endocarditis
must be prevented in these patients. AP is best avoided in AIDS patients
unless severe neutropenia is present (<500 cells per mm3). Under
those conditions, the patient will require antibiotic prophylaxis.
Patients who had surgically corrected cardiovascular
lesions should be given AP up to six months postoperatively. Six
months after surgery, most patients are no longer susceptible unless foreign
material was used or if they have artificial heart valves. AP is required
in patients with the latter two conditions. In patients with pacemakers,
a medical consultation is needed to determine whether AP is necessary.
It is not recommended by AHA, but some physicians may suggest it.
Patients on hemodialysis should be off the dialysis machine for at least
four hours before a dental procedure because of heparin, and AP should
be considered. In patients with joint prosthesis, AP is not necessary
unless they are in the “high risk” category, such as those with rheumatoid
arthritis, diabetes, immuno-suppressed conditions, or previous infection.
The following bleeding disorders may cause
the patient to have post-operative infection and therefore AP should be
considered in surgical cases: thrombocytopenia, systemic lupus erythematosus,
vascular wall alterations, hemophilia, von Willebrand’s disease, liver
disease, and leukemia.
July-August 2001
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