See discussions, st ats, and author pr ofiles f or this public ation at : https:www .researchgate.ne tpublic ation238081510 [614926]

See discussions, st ats, and author pr ofiles f or this public ation at : https://www .researchgate.ne t/public ation/238081510
Antibiotic resistance and antibiotics in endodontics
Article · Januar y 2003
CITATIONS
4READS
222
3 author s, including:
Scott Mc clanahan
Univ ersity of Minnesot a Twin Cities
45 PUBLICA TIONS    1,433 CITATIONS    
SEE PROFILE
All c ontent f ollo wing this p age was uplo aded b y Scott Mc clanahan on 29 May 2014.
The user has r equest ed enhanc ement of the do wnlo aded file.

23

Vol. 25, No. 12 December 2003
Antibiotic resistance and antibiotics in endodontics
Lieutenant Brent. J. Crumpton, DC, USNR, Ca ptain Scott B. McClanahan, DC, USN

Antibiotic resistance has been called one of the world's most
pressing public health problems (1). Antibiotic resistance is not a
new problem. Resistant disease strains began emerging not long
after the discovery of a ntibiotics more than 50 years ago. Penicillin
and other antibiotics, which were initially viewed as miracle drugs
for their ability to cure such serious and often life -threatening
diseases as bacterial meningitis, typhoid fever, and rheumatic fever,
soon were challenged by some defiant strains (2). Antibiotic
resistance is a major contributor to the disease, death, and costs
resulting from hospital -acquired infections. One report placed the
annual cost of antimicrobial resistance among a single pathogen
(Staphylococcus aureus ) at $122 million (3). Antibiotic resistance
has made potential killers out of bacteria that previously posed little
threat to mankind. The indiscriminate and reckless use of antibiotics
has led to a fast – approaching crisis in which human dominance of
the planet is threatened by single, elementary cells of the microbial
world (4). Reasons for the development of antimicrobial resistance
fall into two broad categories: over -prescription by health -care
providers and improper use by pat ients. Although physician over –
prescription for upper respiratory infections is the single largest
reason for the development of resistant microbial strains (5), over –
prescription for dental problems and/or dental pain is emerging as a
growing threat. Th e purpose of this clinical update is to review the
Centers for Disease Control and Prevention (CDC) recommendations
regarding antibiotic use and to review the literature regarding
antibiotic use in endodontics.
How resistance occurs
The ability of antibio tics to stop an infection depends on killing or
halting the growth of harmful bacteria. Some bacteria have
developed a natural resistance to antibiotics, long before the
development of commercial antibiotics. If they are not naturally
resistant, bacteria can become resistant to drugs in a number of
ways. They may develop resistance to certain drugs spontaneously
through mutation. Mutations are changes that occur in the genetic
material, or DNA, of the bacteria. These changes allow the bacteria
to fight or inactivate the antibiotic (6).
Bacteria also can acquire resistant genes through exchanging genes
with other already resistant bacteria. The bacteria reproduce rapidly,
allowing resistant traits to quickly spread to future generations of
bacteria. Th is means that resistance can spread from one species of
bacteria to other species, enabling them to develop resistance to
multiple classes of antibiotics (6).

The emergence of a resistant population of bacteria in a patient as a
result of antibiotic use g enerally occurs through a process termed
"selective pressure." Studies using special culture techniques show
that healthy persons normally harbor small numbers of bacteria that
are intrinsically resistant to antibiotics. The larger numbers of
antibiotic -susceptible organisms usually keep resistant bacteria in
check. The use of any antibiotics eliminates organisms susceptible
to that drug at the site of infection and at all sites in the body into
which the drug penetrates in adequate concentrations. Selecti ve pressure occurs when the administration of an antibiotic decreases
the numbers of normal flora, allowing resistant bacteria to proliferate
(5).
Recommendations for the prudent use of antibiotics
Misuse of antibiotics increases the chances of superinfec tions,
mutations, genetic transfer, and the development of multi -drug
resistant strains of bacteria (7). The CDC estimates that about 100
million courses of antibiotics are prescribed by office -based
physicians each year, and that approximately one half o f those
prescriptions are unnecessary (5). To curb the widespread overuse
of antibiotics, the CDC has published broad guidelines regarding the
prescription of antimicrobials.
CDC’s recommendations for appropriate antibiotic use for health
care providers (1):
• Only prescribe antibiotic therapy when likely to be beneficial to
the patient
• Use an agent targeting the likely pathogens
• Use the antibiotic for the appropriate dose and duration
It is up to health -care providers to educate patients on the risks and
benefits of proper antibiotic use. Clinicians should explain to
patients that antibiotics are potentially harmful in the following
ways:
• Increased colonization and infection with resistant pathogens in
patients with prior antibiotic therapy
• Increased an timicrobial resistance in the community
• Unwanted allergic reactions and adverse effects of antibiotics
• Cost of unnecessary therapy

Empathize with patients about the effect of symptoms on their daily
activities, provide them with educational materials a nd prescribe
therapies to alleviate their symptoms.

Other educational points to covey to patients include:
• Don't demand an antibiotic when the health -care provider
determines one isn't appropriate.
• Finish each prescription. Even when the symptoms of a n illness
have disappeared, some bacteria may still survive and
reproduce if the patient doesn't complete the course of
treatment.
• Don't take leftover antibiotics or antibiotics prescribed for
someone else. These antibiotics may be inappropriate for the
current infection, and taking the wrong medicine could delay
getting appropriate treatment and allow bacteria to multiply.

Indications for antibiotic therapy in endodontics
The first point to consider is that antibiotics should only be used as
an adjunct t o definitive non -surgical or surgical endodontic therapy.
Removal of the etiology is ultimately the goal of treatment. Pulpal
debridement and/or surgical access are the primary treatment for all
endodontic infections. Even then, the rationale for antibi otic
therapy is a severe infection in which the organism is not known and Clinical Update Naval Postgraduate Dental School
National Naval Dental Center
8901 Wisconsin Ave
Bethesda, Maryland 20889 -5602

24 major consequences would ensue if therapy is not initiated before
culture and sensitivity tests are available.

Accordingly, the primary indications for antibiotic use are:
• Compro mised host resistance
• Systemic involvement
• Fascial space involvement
• Inadequate surgical drainage
Other indications for the use of antibiotics include the prophylactic
treatment for preventing endocarditis and prosthetic joint infection,
as well as prophy lactic coverage following a sodium hypochlorite
accident (8). If multiple appointments are planned for patients
requiring antibiotic prophylaxis, scheduling should allow for a
minimum of 10 days between appointments in order to minimize the
odds that bact erial strains will develop resistance (9). When
multiple appointments in succession are needed, changing the class
of antibiotic (i.e. from amoxicillin to clindamycin) will help curb the
risk of bacterial resistance (10).
Proper antibiotic selection is c ritical. An antibiotic with a broad
enough spectrum to cover the bacterial etiology is essential, but not
too broad in which to kill beneficial normal flora. Hence, penicillin is
still the drug of choice in endodontic infections. A recently
published st udy reported that penicillin V was effective in 81% of
acute endodontic infections. The same study found that
metronidazole was effective in 88%, and clindamycin in 89% of
infections. When penicillin V and metronidazole were combined the
effectiveness in creased to 93.2% (11).
After drug selection, the next important step is selection of the
appropriate dose and duration. Studies within the past few years
have shown that up to 40% of providers are using inappropriate
adult doses (12,13). The proper adul t dosages for commonly
prescribed antibiotics are as follows (without renal impairment):
• Penicillin V 500mg
Sig: 2 p.o. STAT; then 1 p.o. every 6 hours for 7 days
• Metronidazole 500mg
Sig: 1 p.o. every 6 – 8 hours for 7 days
• Clindamycin 150 -300mg
Sig: 1 p.o. every 6 hours for 7 days
In a year 2000 survey of members of the American Association of
Endodontists (AAE), a loading dose of penicillin was reported by
85% of providers; hence, its inclusion in the above
recommendations (14).
When not to presc ribe antibiotics
Endodontic diagnoses in which the prescription of antibiotics are
not warranted include irreversible pulpitis with or without acute
periradicular periodontitis, necrotic pulp with or without acute
periradicular periodontitis, necrotic pulp with a draining sinus tract,
and a necrotic pulp with chronic periradicular periodontitis without
swelling. Research has shown that penicillin does not reduce pain,
percussion sensitivity, or the amount of analgesics required in
untreated teeth diagnosed with irreversible pulpitis; and therefore,
should not be prescribed in cases of irreversible pulpitis (15). The
reason is that irreversible pulpitis is an immune system mediated
event, which is most often not due to a bacterial infection, but rather
is a result of inflammatory mediators overcoming the host defenses
(16). The prophylactic use of antibiotics to prevent potential flare –
ups has also been shown to have no effect on their occurrence, and cannot be recommended as routine protocol in the treatme nt of
asymptomatic necrotic teeth (17) .
Nearly all groups of practitioners are guilty of over -prescribing. In
the AAE survey mentioned above, for cases of irreversible pulpitis,
16.76% of responders prescribed antibiotics. In cases of a necrotic
pulp, a cute apical periodontitis, and no swelling, 53.93% prescribed
antibiotics. Nearly 12% prescribed antibiotics for necrotic pulps
with chronic apical periodontitis and a sinus tract (14).
Conclusions
Antimicrobial therapy is an invaluable and sometimes l ife-saving
adjunctive therapy. Inappropriate and indiscriminate use, has led to
wide -spread antibiotic resistance, which if not curbed, will lead to
bacteria that are resistant to all present antibiotics (18). Prudent
usage of antibiotics rests upon prov iders. Meeting this
responsibility will ultimately help to determine whether we have
effective antimicrobials in the future.
References :
1. http://www.cdc.gov/drugresistance/community/ CDC Background on
Antibiotic Resistance. 2003.
2. Nordenberg T. Mira cle Drugs vs. Superbugs. FDA Consumer Magazine,
1998 Nov -Dec 32(6):22 -5.
3. www.cdc.gov/ncidod/HIP/aresist/am_res.htm , Antimicrobial resistance: A
growing threat to public health. 1999.
4. Harrison JW, Svec TA. The beginning of the end of the antibiotic era?
Part II. Proposed solutions to antibiotic abuse. Quintessence Int. 1998
Apr;29(4):223 -9.
5. Colgan R, Powers JH. Appropriate antimicrobial prescribing: Approaches
that limit antibiotic re sistance Am Fam Physician. 2001 Sep 15;64(6):999 –
1004.
6. Bren L. Battle of the bugs: fighting antibiotic resistance. FDA Consum.
2002 Jul -Aug;36(4):28 -34.
7. Harrison JW, Baumgartner JC, Svec TA. Incidence of pain associated with
clinical factors during a nd after root canal therapy. Part 1. Interappointment
pain. J Endod. 1983 Sep;9(9):384 -7.
8. Hales JJ, Jackson CR, Everett AP, Moore SH. Treatment protocol for the
management of a sodium hypochlorite accident during endodontic therapy.
Gen Dent. 2001 May -Jun;49(3):278 -81.
9. Leviner E, Tzukert AA, Benoliel R, Baram O, Sela MV. Development of
resistant oral viridans streptococci after administration of prophylactic
antibiotics: time management in the dental treatment of patients susceptible to
infective en docarditis. Oral Surg Oral Med Oral Pathol . 1987 Oct;64(4):417 –
20.
10. Dajani AS, Taubert KA, Wilson W, Bolger AF, Bayer A, Ferrieri P, et al .
Prevention of bacterial endocarditis. Recommendations by the American Heart
Association. Clin Infect Dis. 1997 De c;25(6):1448 -58.
11. Khemaleelakul S, Baumgartner JC, Pruksakorn S. Identification of bacteria
in acute endodontic infections and their antimicrobial susceptibility. Oral Surg
Oral Med Oral Pathol Oral Radiol Endod. 2002 Dec;94(6):746 -55.
12. Epstein JB, Chong S, Le ND. A survey of antibiotic use in dentistry. J Am
Dent Assoc. 2000 Nov;131(11):1600 -9.
13. Roy K, Bagg J. Antibiotic prescribing by general dental practitioners in the
greater Glasgow Health Board Scotland. Br Dent J. 2000 Jun 24;188(12):674 –
6.
14. Yingling NM, Byrne BE, Hartwell GR. Antibiotic use by members of the
American Association of Endodontists in the year 2000: report of a national
survey. J Endod. 2002 May;28(5):396 -404.
15. Nagle D, Reader A, Beck M, Weaver J. Effect of systemic penic illin on
pain in untreated irreversible pulpitis. Oral Surg Oral Med Oral Pathol Oral
Radiol Endod. 2000 Nov;90(5):636 -40.
16. Bergenholtz G. Pathogenic mechanisms in pulpal disease. J Endod. 1990
Feb;16(2):98 -101.
17. Pickenpaugh L, Reader A, Beck M, Meye rs WJ, Peterson LJ. Effect of
prophylactic amoxicillin on endodontic flare -up in asymptomatic necrotic
teeth. J Endod. 2001 Jan;27(1):53 -6.

25 18. Slavkin HC. Benefit -to-risk ratio: the challenge of antibiotic drug
resistance. J Am Dent Assoc. 1997 Oct;128(10 ):1447 -51.

Lieutenant Crumpton is a second -year resident in the Endodontics
Department. Captain McClanahan is the Chairman of the Endodontics
Department at the Naval Postgraduate Dental School.

The opinions and assertions contained in this article are t he private ones of
the authors and are not to be construed as official or reflecting the views of the
Department of the Navy.

Note: The mention of any brand names in this Clinical Update does not
imply recommendation or endorsement by the Department of the Navy,
Department of Defense, or the U.S. Government.
View publication statsView publication stats