A major reason for the prophylactic use of antibiotics with certain
dental procedures is the prevention of bacterial endocarditis, a
serious infection of the heart's inner lining and/or the heart's
valves. I've gathered some data that will help to provide an overview
of this subject (for copyright reasons, I am posting only brief
excerpts from this material; more information in depth may be found by
reading the complete articles linked below.)
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"Why do some people take antibiotics before some dental procedures?
Any time there is bleeding in the mouth, oral bacteria can enter the
bloodstream. The body's immune system usually then destroys the
bacteria.
In people who have certain heart diseases or deformities, however, the
bacteria may settle on abnormal heart valves or heart muscle tissue
that has been weakened by an existing heart problem or heart surgery.
In these cases, the bacteria can cause a serious inflammation of the
heart valves or tissues called bacterial endocarditis.
To reduce the risk of bacterial endocarditis, people with certain
heart conditions will be given one dose of an antibiotic to take
approximately one hour before dental procedures that are likely to
cause oral bleeding."
American Dental Association: Your Oral Health and Overall Health
http://www.ada.org/public/faq/health.html
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"Bacterial endocarditis occurs when bacteria in the bloodstream
(bacteremia) lodge on abnormal heart valves or other damaged heart
tissue. Certain bacteria normally live on parts of your body, such as
the mouth and upper respiratory system, the intestinal and urinary
tracts, and the skin. Some surgical and dental procedures cause a
brief bacteremia. Bacteremia is common after many invasive procedures,
but only certain bacteria commonly cause endocarditis."
American Heart Association: Bacterial Endocarditis
http://www.americanheart.org/presenter.jhtml?identifier=4436
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"Certain heart conditions and structural defects increase the risk of
developing endocarditis (a heart valve infection) following dental
procedures. Bacterial Endocarditis means infection in the heart,
specifically the heart valves (bacteria = germs; endo = inside;
carditis = heart inflammation). It occurs when bacteria spread through
the bloodstream and land inside the heart and grow there. Usually, if
there are bacteria circulating in the bloodstream, they don't stick to
the inside of the heart: the blood flows smoothly. If the heart is
abnormal due to certain types of surgery or other defects, there may
be rough surfaces causing turbulent blood flow (known as a murmur) to
which bacteria can attach and cause infection. Antibiotics are used to
try to prevent this dangerous infection in some cases. The decision
whether to take antibiotics depends on two major factors: first, is
the procedure likely to cause a significant number of bacteria to
enter the bloodstream; and second, is the heart particularly subject
to infection. Some dental procedures are more likely to cause
bacteremia (bacter = bacteria, and emia = in the blood) than others."
University of Manitoba: Dental Work and the Risk of Bacterial
Endocarditis
http://home.cc.umanitoba.ca/~soninr/DentalWork.pdf
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Below are some of the American Heart Association's guidelines for the
use of antibiotic prophylaxis in dentistry. (Note: "Prophylaxis" means
"prevention of disease").
"Antibiotic prophylaxis is RECOMMENDED for the following:
High-risk category
Prosthetic cardiac valves,including bioprosthetic and homograft valves
Previous bacterial endocarditis
Complex cyanotic congenital heart disease (e.g., single ventricle
states, transposition of the great arteries, tetralogy of Fallot)
Surgically constructed systemic pulmonary shunts or conduits
Moderate-risk category
Most other congenital cardiac malformations (other than above and
below)
Acquired valvar dysfunction (e.g., rheumatic heart disease)
Hypertrophic cardiomyopathy
Mitral valve prolapse with valvar regurgitation and/or thickened
leaflets"
Dr. Rajiv Khosla: Antibiotics & Dentistry
http://members.rediff.com/drkhosla/antibiotics.html
"Antibiotic prophylaxis is NOT RECOMMENDED for the following:
Negligible-risk category (no greater risk than the general population)
Isolated secundum atrial septal defect
Surgical repair of atrial septal defect, ventricular septal defect, or
patent ductus arteriosus
Previous coronary artery bypass graft surgery
Mitral valve prolapse without valvar regurgitation
Physiologic, functional, or innocent heart murmurs
Previous Kawasaki disease without valvar dysfunction
Previous rheumatic fever without valvar dysfunction
Cardiac pacemakers (intravascular and epicardial) and implanted
defibrillators"
Dental Gentle Care: Antibiotic Guidelines for Dental Treatment
http://www.dentalgentlecare.com/new_page_1.htm
"If you identify with a condition in the high or moderate risk groups,
then antibiotic prophylaxis is recommended for the following dental
procedures:
Dental extractions
Periodontal procedures including surgery, scaling and root planing,
probing, and recall maintenance
Dental implant placement and reimplantation of avulsed teeth
Endodontic (root canal) instrumentation or surgery only beyond the
apex
Subgingival placement of antibiotic fibers or strips
Initial placement of orthodontic bands but not brackets
Intraligamentary local anesthetic injections
Prophylactic cleaning of teeth or implants where bleeding is
anticipated
Antibiotic prophylaxis is not recommended for the following dental
procedures:
Restorative dentistry (operative and prosthodontic) with or without
retraction cord
Local anesthetic injections (nonintraligamentary)
Intracanal endodontic treatment; post placement and buildup
Placement of rubber dams, postoperative suture removal, taking of oral
impressions, and fluoride treatments
Placement of removable prosthodontic or orthodontic appliances and
orthodontic appliance adjustment
Taking of oral radiographs
Shedding of primary teeth"
Quality Dentistry: Antibiotic Prophylaxis Guidelines
http://www.qualitydentistry.com/dental/information/abiotic.html
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Much more information may be found in these articles:
Heart Center Online: Dental Care & Your Heart
http://www.heartcenteronline.com/myheartdr/common/artprn_rev.cfm?filename=&ARTID=391
American Dental Association: Prevention of Bacterial Endocarditis: A
Statement for the Dental Profession
http://www.ada.org/prof/pubs/jada/reports/endo/ada.html
American Dental Association: JADA Special Report
http://www.ada.org/prof/pubs/jada/reports/endo/report/sect-1.html
Affinity Laboratory Technologies: Focal Infection
http://www.altcorp.com/AffinityLaboratory/focalinfect.htm
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You pose an interesting question: "If the immune system is always
working to gain the upper hand, fighting off bacteria and viruses, why
might antibiotics be recommended anyway." Antibiotics are often
recommended as a preventive measure to ensure that complications such
as bacterial endocarditis will not occur. While it's true that, in
many cases, a person's own immune system might be able to handle the
problem, the seriousness of the worst-case scenario is weighed against
the relative safety and small expense of antibiotic treatment. The old
saying "Better safe than sorry" may be applied here. Even if there is
no certainty that a dental procedure will lead to endocarditis, the
fact is that there is a significant risk (for certain patients, at
least). The prophylactic use of antibiotics can greatly reduce that
risk, which benefits both the patient (who avoids incurring permanent
heart damage) and the practitioner (who avoids a potentially
disastrous lawsuit).
It should be noted that this matter is not without controversy. There
has been much debate on the subject, and there is no universal
agreement on precise guidelines for the use of antibiotics in
dentistry:
"In recent years there has been an increasing tendency to reduce the
widespread use of antibiotics for prophylactic and therapeutic
purposes. This is based, both on increasing scientific evidence and
enhanced professional experience. The development of resistant
strains of micro-organisms, doubt on the efficacy of the proposed
prohylactic regimens, possible toxic and adverse reactions to
antibiotics and poor compliance by patients and dentists raised
questions about risks and benefits.
There clearly is a trend towards covering only a limited number of
invasive dental procedures and this in fewer and more specific medical
conditions.
Today there is no clear consensus among experts on the use of
antibiotics in dentistry. This is because scientific evidence for the
indications is often lacking."
European Academy of Paediatric Dentistry: Guidelines on the use of
antibiotics in Paediatric Dentistry
http://www.eapd.gr/Guidelines/Guidelines_Antibiotics.htm
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Google search strategy:
Google Web Search: "antibiotics" + "dental" + "endocarditis"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=antibiotics+dental+endocarditis
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I hope this information is helpful. Please keep in mind that Google
Answers is not a source of authoritative medical advice; the material
I've presented here is for informational purposes, and is not a
substitute for the services of a qualified medical professional.
If anything is unclear, or if a link does not function, please request
clarification; I'll be glad to offer further assistance before you
rate my answer.
Best wishes,
pinkfreud |
