1. Antibiotics in Dentistry
Iyad Abou Rabii DDS, OMFS, MRes, PhD
QASSIM UNIVERSITY

2. Antibiotics in Dentistry
Iyad Abou Rabii DDS, OMFS, MRes, PhD
Antibiotic is a a chemical substance derivable from a mold or bacterium that can kill
microorganisms and cure bacterial infections
Best use of Antibiotics
Cardinal Rules:
1. Use the right drug.
2. Use the right dose.
3. Use the correct dosing schedule.
4. Correct duration.
5. Use a loading dose to rapidly achieve therapeutic blood levels.
6. Avoid combinations of bacteriostatic and bacteriocidal drugs.
Chose well
1. Narrow Spectrum?
2. Extended/Broad Spectrum?
3. Designer Antibiotics?
4. Anaerobes? Consider if the infection is present > 3days or if no improvement
Know your enemy (bateria)
1. Gram Positive?
2. Gram Negative?
3. Mixed Infection?
4. Anaerobes?
Identify your weapon
1. Specific for the pathogen.
2. Fewer disturbances of non-pathogenic bacteria.
3. Fewer side effects.
4. Rapid response for sensitive organisms. Ex: Pen VK, Pen G, Erythromycin
5. Affects both Gram + and Gram - bacteria, better for mixed infections.
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6. May give up some effectiveness for Gram + to gain effectiveness for Gram
Examples: Amoxicillin, Ampicillin
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Identify you patients
1. Age, allergies, compliance, pregnancy risk
2. Patient function
3. Renal, hepatic, immunosuppresion, route applicability
4. Cost Brand name, length of course, alternatives?
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3. Prophylactic antibiotic
The goal of antibiotic prophylaxis in Odontology is to prevent the onset of
infections through the entrance way
provided by the therapeutic action, therefore it is indicated provided there is a
considerable risk of infection,
either because of the characteristics of the operation itself or the patient’s local
or general condition.
The physician’s criterion for choosing antibiotic prophylaxis or not must be based
on the benefit and the cost of the risk. In the last instance, the prophylaxis
decision is the choice of the physician, who will use the equation:
risk = degree of damage x probability of experiencing it.
To that aim, patients could be classified as:
a)healthy patients,
b) patients with local or systemic infection risk factors, and
c) patients with post-bacteraemia focal infection risk factors.
In healthy subjects, prophylaxis is based exclusively on the risk of the procedure.
Topical Antibiotics
Pharmaceutical Forms
Some topical antibiotics are available without a prescription and are sold in
many forms, including creams, ointments, powders, and sprays. Some widely
used topical antibiotics are bacitracin, neomycin, mupirocin, and polymyxin B.
Among the products that contain one or more of these ingredients are
Bactroban (a prescription item), Neosporin, Polysporin, and Triple Antibiotic
Ointment or Cream.
Antibiotic mouthwash can be prepared by the patient by dissolving the contents
of 250 mg tetracycline capsule in 10 ml of water to give a 2% solution. It may be
more effective to add glycerol to the solution as a demulcent, this must be done
by pharmacist.
Advantages
The value of topical antibiotics overweighs such risks in some cases. Tetracycline
is a useful topical antibiotics. As at 2% solution it’s often effective in reducing
secondary infection (and thus the discomfort) in cases of aphtous stomaitis,
primary herpetic stomaitis, and all oral ulcerative conditions.
Use of topical antibiotics is also seen to be helpful in acute chronic gingivitis
treatment.
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Disadvantages
There are inherent disadvantages associated with the use of topical antibiotics
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because of the possibilities of selection for resistant strains and inducing
hypersensitivity reaction at the patient.
Use of Topical Antibitics
Indication
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4. Topical antibiotics help prevent infections caused by bacteria that get into minor
cuts, scrapes, and burns. Treating minor wounds with antibiotics allows quicker
healing.
They are always used to prevent secondary infection (ulcers)
Duration
The use of topical antibiotics cannot normally be practiced as long- term
treatment, it is better to be reserved for acute episodes. Otherwise, there will be
the risk of overgrowth of resistant organisms, although a candidal infection may
occur. However, in some rare cases a prolonged topical antibiotic treatment is
justified (Patients with severe and persistent oral lesions), in that case a
tetracycline with triamcinolone combination is preferred
Topical antifungal treatment
Antifungal drugs
The polyene antifungal agents, nystatin and amphotericin B, are well
established and relatively free from side-effects when used locally. They are
available in various forms, such as lozenges, pastilles, creams, and suspensions.
Unfortunately, patient compliance is often poor with these preparations, which
may take a while to dissolve in the mouth (for example, pastilles and lozenges)
and have a a distinctive taste.
The newer azoles have very useful properties, although resistance is rather more
commonly met and may be problematic in the future, particularly in the
immunocompromised patient. (C. krusei and and C. glabrata are usually resistant
to fluconazole.) The locally active agent, miconazole is available as an oral gel or
cream.
Pharmaceutical Forms
Conventional
In order to assure topic application of antifungal agents, conventional lozenge,
mouthwash, or gel would be the simplest dosage forms for the delivery of drugs
in the buccal cavity, but these conventional dosage forms had the disadvantage
of an initial burst of salivary concentration followed by a rapid decrease. A
lozenge produced effective salivary drug levels for more than one hour but
repeated administration was restricted due to systemic toxicity coming from the
large quantity of ingested drug. The action of mouthwashes was even more
transient than that of lozenges, and gels/pastes were difficult to retain in the
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mouth .
Sustained Release forms
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In case of oral fungal infections, a prolonged therapy with antifungal agent was
required, and some papers documented prolonged release of antifungal agent
from buccal devices in the form of an adhesive tablets.
I.Abou Rabii et al (2004, France) has developped a Miconazole musoadhesive
tablette which has been given higher concentration of Miconazole in Saliva
(Over the IMC for more than 9h).
Topical antifungal therapy
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5. Pseudomembranous, erythematous hyperplastic candidosis
Amphotericin lozenges (10 mg)
Nystatin pastilles (100 000 units)
Dissolve slowly in mouth, after meals; use 4 times daily;
Candida-associated denture stomatitis
Amphotericin or nystatin (as above) and remove dentures
Miconazole gel applied to palatal surface of denture 4 times daily for 1 to 4
weeks
Chlorhexidine 0.2% rinse, 4 times daily (do not use with nystatin)
Candida-associated angular cheilitis
Nystatin cream; apply to corners of mouth 3 to 4 times daily, until resolution
Miconazole cream (or gel); apply 3 to 4 times daily to angles
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