Mohammed A. Al-Muharraqi MBChB (Dnd.), BDS (Dnd.), MDSc (Dnd.), MRCS (Glas.), FFD RCS (Irel.), MFDS RCS (Eng.) Consultant OMF Surgeon & Oral Physician - BDF Hospital Senior Lecturer – RCSI Medical University of Bahrain Kingdom of Bahrain [email protected] Pharmacology & Therapeutics in
Learning Outcomes
Medical Conditions and Their Impact on Dental Care.  We are all dealing with an increasing ageing Medical Emergency & Resuscitation in the Dental Practice. population who are retaining their teeth well into old The Special Care Needs Patient. age. A large proportion of this population will be Geriatrics: Oral Medicine and the Ageing Patient. taking one or two medicines to enable them to Management of the Oncologic Patient. continue with their normal daily activities. Oral Soft Tissue Lesions, Temporomandibular Disorders and  Certain drugs are the mainstay of dental practice. Infections, Infectious Diseases and Dentistry. These include antibiotics, analgesics, local anesthetics, Nutrition and Oral Health. Clinical & Applied Pharmacology and Dental therapeutics. and agents to control anxiety. Pharmacology & Therapeutics in

 Many of our patients are medically compromised and this  Antibiotics are chemical substances produced by raises three important issues with respect to the delivery of microorganisms, which have the capacity, in dilute routine dental care: solutions, to inhibit the growth of (bacteriostatic) or to
Can the patients medication cause an adverse reaction in the mouth and associated structures?  They are hugely significant compounds in medical practice Can the drugs that I wish to prescribe interact with their current medication? with lifesaving properties.
What medical emergencies are likely to arise in this population and how should they be dealt with? Antibiotic Therapy in Managing
Odontogenic Infections
 However, they are also the subject of intensive abuse, both  Many new antibiotics/antimicrobials have been developed, but none
have been determined of significant benefit to replace or supplant
the use of penicillins for the management of orofacial infections.
inappropriate reasons. This has led to the worldwide
problem of bacterial resistance.  Sensible use of antibiotics in conjunction with surgical therapy is the
most appropriate method to treat odontogenic infections.  These drugs are used extensively in dentistry for two main
 Using the antibiotic ‘‘du jour,'' many times promoted by pharmaceutical representatives, results in costly and unnecessary 1. to prevent an infection (chemoprophylaxis) and complexity of care. 2. in the treatment of an infection. 3. Their use in the management of periodontal diseases is often as an A return to the basics is indicated for the antibiotic management
adjunct to conventional treatment. of odontogenic infections!
Antibiotic Therapy in Managing
Antibiotic Therapy in Managing
Odontogenic Infections
Odontogenic Infections
Chemotherapy is the use of synthetic, semi-synthetic, and naturally
 The determination as to whether conjunctive antibiotic therapy is
occurring chemicals that selectively inhibit specific organisms causing indicated is based on several factors, including:  host defence mechanisms,  host underlying medical condition,  The term antibiotic means ‘‘against life'' (anti = against and biosis =
 severity of the infection,  magnitude of the extension of the infection, and  expected pathogen.  The clinician must first diagnose the cause of the infection and
 Because of the lack of circulation within dental pulp, the normal
determine the appropriate dental treatment that may include
host defences (inflammation and immunity) are compromised and
multiple modalities: initiation of endodontic therapy and
the root canal system becomes a unique environment to harbour a pulpectomy, odontectomy, or surgical or mechanical disruption
limited group of bacteria. of the infectious environment.
Antibiotic Therapy in Managing
Antibiotic Therapy in Managing
Odontogenic Infections
Odontogenic Infections
Most odontogenic infections are polymicrobial and are composed of
 An abscess, a fibro-collagenous layer of tissue, may form around an
at least two predominating bacteria. accumulation of PMNs in the region of infection, isolating it from
surrounding tissue.  Most bacteria comprising the oral flora are non-pathogenic and have
NOT been shown to proliferate and grow in host tissue .
 Because the host may be unable to resorb the abscess and resolve
the infection, RCT, extraction, or other surgical therapy is needed to
 When the dental pulp is overwhelmed from the bacterial attack, a
remove the cause.
local acute inf lammatory response is seen, followed by
nonspecific and specific immunologic reactions with the presence of
 Recent studies demonstrate that a localized abscess may be an
lymphocytes, plasma cells, and macrophages. inf lammatory/immunologic phenomenon and in some patients
represents a non-bacterial cause for the periapical localized
polymorphonuclear clinical symptoms (Torabinejad M et al, 1994; Kettering JD et al, 1991) chemotactically attracted to the area of damaged tissue.
Antibiotic Therapy in Managing
Antibiotic Therapy in Managing
Odontogenic Infections
Odontogenic Infections
 Oral antibiotic as primary and sole treatment for an
 Many clinicians, however, do treat odontogenic infections infection of odontogenic aetiology is highly
primarily with antibiotics. questionable because of the lack of effective
circulation in a necrotic pulp system and an abscess.  Endorsement of a philosophy of care that antibiotic administration is low risk and potential high yield
be substantiated, especially with the current
 This concept reinforces that surgery of some kind is
concern regarding bacteria that have developed resistance the primary treatment of an infection of
to current antibiotic therapy. odontogenic source, and antibiotic therapy is
Antibiotics should not be prescribed as a substitute for
proper dental treatment!
Mechanism of Action
Mechanism of Action
 Antibiotics have various effects on bacteria based on their
 Metronidazole, indicated in dentistry for anaerobic pharmacologic action. bacterial infections, is a direct-acting agent that binds
 The most commonly used antibiotics in dentistry
and degrades DNA in bacteria.
(penicillins, cephalosporins, and vancomycin) work by attacking the cellular processes necessary for the
 Still other antibiotics (amphotericin B, polymixins) act by bacterial cell wall synthesis while having no effect on
inhibiting cell membrane function.
host cells.
Other commonly used antibiotics in dentistry exert their
 Further development in determining the difference
effect by inhibiting translation needed for bacterial
between host and bacterial protein synthesis may lead
to the development of alternative sensitive and specific aminoglycosides, and chloramphenicol). antibiotic therapeutics. Mechanism of Action
Mechanism of Action
New synthetic antibiotics for potential use in dental-related
 The emergence of resistant bacteria is growing.
infections are the quinolones (cinoxacin, nalidixic acid, and  The microbial ecosystem is engaged in trying to remain methenamine) and the fluoroquinolones (ciprofloxacin, norfloxacin, opportunistic and by mutating and adapting, RESISTANT
 These agents should ONLY be considered when culture results have
revealed that these antibiotics are warranted.
 Specific enzymes can destroy the antibiotic once it has
 They have a broader spectrum of action and inhibit bacterial DNA
entered the bacteria, replication (fluoroquinolones inhibit DNA gyrase that inhibits the
 permeability into the cell wall can become difficult, and uncoiling of DNA for replication).  an alteration of certain targets that the drug attaches to  The limited indication and the high cost of these drugs is a serious
become apparent. consideration before prescribing.  Mutations in any of these functions can result in loss of
sensitivity and specificity to any antibiotics.
They are rarely used in the management of odontogenic infections!
Mechanism of Action
Indications for the Use of Antibiotics
 Bacteria have two major advantages that allow them to
 Clinical effectiveness in treating an infection is based on survive and prosper in the host system.
correct diagnosis.
 They replicate quickly and can produce multiple mutations spontaneously – once a mutation is present, all bacteria  Once the source has been established, dental procedures
offspring generally acquire the new trait. should be used immediately to disrupt the
 Genetic transfer is another process that bacteria possess – microorganisms involved.
it allows families of bacteria to share desirable traits
with a wide range of microbial species.
 Antibiotic therapy should be used as an adjunct to dental
It has recently been found that antibiotic-resistant
treatment and never used alone as the first line of care. genes can be passed among EVERY species of bacteria!
Indications for the Use of Antibiotics
Indications for the Use of Antibiotics
 Antibiotics are indicated when systemic signs of involvement are  The choice of an antibiotic should be based on knowledge of the
usual causative microbe.
eate r NOT
than 38 ° r
C equire antibiotic
The empiric approach usually results in favourable outcomes.
ate greater than 90 beats per minute
≥ 37.7°C (100°F), malaise, lymphadenopathy, or trismus Tachypnea (high respiratory rate), with greater than 20 breaths per
Penicillin is the first choice in managing odontogenic infections
because it is susceptible to gram-positive aerobes and intraoral kPa . ( 3 2 mmHg) anaerobes, organisms found in alveolar abscesses, periodontal
abscesses, and necrotic pulps.
greater than 12,000 cells/mm³ (12 x 109 cells/L); or the presence of indications for which one may prescribe an antibiotic. greater than 10% immature neutrophils (band forms)  Clinic ians should consider consulting a specialist if the
 Patients with compromised host defence systems may indicate
swelling spreads to extraoral spaces or obstructs breathing or
antibiotic therapy in conjunction with their dental treatment –
organ transplant patients and patients with poorly controlled diabetes. Indications for Culturing
Indications for Culturing
Rarely required in managing odontogenic infections, but is necessary
Indications for culturing odontogenic infections:
to resolve a progressive infection. 1. The patient is not responding to the first antibiotic  Culturing methods have improved over the years; however, bias may occur prescribed after 48 hours and appropriate dental
during the isolation and culturing of bacteria. treatment has been completed. 2. The infection is progressing to other facial spaces.  Many anaerobic microbes are killed quickly when exposed to oxygen.
3. The patient is immunocompromised or has a history of  Needle aspiration techniques and transfer under inert gas should be used bacterial endocarditis and is not responding to the
when culturing for aerobic and anaerobic bacteria in the oral cavity.
antibiotic therapy.  Antibiotic treatment should begin immediately even
 The antibiotic is then chosen to treat the predominant microbe found in when a culture is taken because of the rapid spread of oral the culture if empiric therapy has failed.
Antibiotics of Choice
Antibiotics of Choice
Penicillin is still the gold standard in treating dental infections.
 Certain bacteria can develop resistance to the penicillins because of
 Penicillin has contributed to a dramatic decrease in mortality in the B-lactamase enzymes that inactivate the penicillin.
serious odontogenic infections such as Ludwig's angina and diffuse
 A combination antibiotic consisting of a penicillin and clavulanic
orofacial cellulitis. acid, a B-lactamase inhibitor, or the use of clindamycin, an
 Aerobic and anaerobic microorganisms are susceptible to penicillin
antibiotic specific for infections caused by staphylococci, streptococci, (Sabiston CB et al, 1974) pneumococci, and other bacterial species may be necessary in an
infection not responding to penicillin alone.
Pen VK is the obvious choice over Pen G because of the greater oral
absorption by Pen VK. cephalosporin) provide a SLIGHTLY broader antibiotic spectrum,
Pen VK is bactericidal and active against replicating bacteria often
especially in gram-positive organisms are suspected. encountered in odontogenic infections (Smith CM et al, 1992)  The side effect encountered most often in penicillin is hypersensitivity, Cephalosporins beyond the first generation are not indicated in
which is found in roughly 3–5% of the population.
most odontogenic infections!
Antibiotics of Choice
Antibiotics of Choice
 If an antibiotic is warranted, providing adequate blood
 If within 48 hours the patient is not responding to penicillin, one could
consider adding metronidazole.
levels is essential.
 It is prescribed in a 500-mg dose every 8 hours for the duration of the
 A loading dose of 2000 mg Pen VK approximately 1 hour
antibiotic therapy. before beginning surgical therapy followed by 500 mg
 Metronidazole is active only against obligate anaerobic bacteria by every 6 hours for 5–7 days is optimal. penetrating all bacterial cells and inhibiting DNA replication.  If the infectious signs and symptoms continue beyond 5–7  It should NOT be used in pregnant patients or patients with a history of
days, additional antibiotic therapy may be indicated.  If combined with ethyl alcohol can produce nausea and vomiting.
Antibiotics of Choice
Antibiotics of Choice
 Another alternative to treat an infection that is not responding
to penicillin is clindamycin.
Appropriate diagnosis and surgical therapy
 It MAY be used as a first-line antibiotic if the infection is deemed
COUPLED with the empiric use of antibiotics
to be more mature and potentially has spread to bone. and sound clinical judgment in assessing
 Indiscriminate use should be avoided. improvement is the STANDARD of care in the
management of odontogenic infections
 A loading dose of 600 mg may be administered approximately 1
hour before surgical therapy begins, followed with 300 mg every
6 hours for the duration of the infection (5–7 days).
Antibiotic Preparations for
A Step-by-Step Approach for Diagnosing &
Odontogenic Infections
Treating Odontogenic Infections
1. Pen VK 500 mg every 6 hours, tablets: 125 mg, 250 mg,
Listen to the chief complaint of the patient. This is the symptom
that the patient is experiencing and describes in his or her own
Take a comprehensive medical history. Review systemic diseases,
2. Amoxicillin 500 mg every 8 hours, tablets: 250 mg
past surgeries, injuries, and medications the patient is taking. Review any allergic responses a patient may have experienced.
3. Metronidazole 500 mg every 8 hours, tablets: 250 mg
Obtain a thorough dental history of existing problems: When
did the problem begin, is it getting worse or better, and what medications is the patient taking for it? Extraoral and intraoral examination for the presence and extent
4. Clindamycin 150–300 mg every 6 hours, capsules: 75 mg
of pathosis. Percussion, palpation, and pulp vitality testing are indicated to diagnose pulpal and periodontal disease. A Step-by-Step Approach for Diagnosing &
A Step-by-Step Approach for Diagnosing &
Treating Odontogenic Infections
Treating Odontogenic Infections
5. Radiographic examination is an adjunct in determining
7. Designing the appropriate dental treatment should
dental disease. Most pathologic states in pulpal tissue are not
be rendered: emergency and definitive treatment. visible on a radiograph. Only when the cortical plate has been resorbed does the dental radiograph become helpful in 8. Case selection completed and referral to a specialist
identifying disease. if found that the patient's needs are beyond the
6. Treatment planning is discussed with the patient once the
capacity of the clinician's capabilities.
nature of the pathosis has been identified. Determine the
difficulty of the case and whether handling it is within
your comfort level or if the case should be referred
. The
9. Appropriate
clinician should calculate a prognosis for each case including a instructions given.
contingency prognosis if problems are encountered after
treatment has begun.
A Step-by-Step Approach for Diagnosing &
Treating Odontogenic Infections

Antibiotic Myths
10. Selection of an antibiotic if warranted:
 There are many myths that pervade the clinical practice of  Choose the narrowest spectrum antibiotic possible to prevent disturbing the
dentists regarding the diagnosis and management of host's normal microbial flora. odontogenic infections.  Prescribe the medication with the appropriate dose and duration.
Educate the patient about the importance of taking the medication for the proper
 These behaviours have been observed repeatedly in the
length of the time. course of clinical practice.
 Provide adequate analgesic therapy along with antibiotic therapy if the patient is
also experiencing pain.  To dispel the continued improper use of antibiotics in the  Closely monitor the patient and follow up in 48 hours to make sure the dental
dental environment, these myths are exposed in this treatment and antibiotic therapies have reduced the patient's symptoms. If there
has not been a reduction in symptoms, consider adding another antibiotic,
culturing the infection, or referring the patient to a specialist.
Myth #1: Antibiotics are Not Harmful
Myth #1: Antibiotics are Not Harmful
 The unnecessary administration of antibiotics is not without  Various degrees of allergic responses have been reported with the use of risk. The risks for pseudomembranous colitis and allergic
common antibiotics used for odontogenic infections.
reaction must be taken into consideration before prescribing.
 Dermatologic reactions such as rash or hives represent milder reactions,
whereas life-threatening anaphylactoid reactions have occurred.  Many antibiotics can disturb the normal microbial flora of
the gastrointestinal tract, which may cause severe diarrhea
 It has been estimated that 100–300 FATAL allergic reactions to
and potentially fatal pseudomembranous colitis. penicillin occur annually in the USA and UK (Rudolph AH at al, 1973; Turck M,
 These reactions occur more frequently when using oral
For an allergic reaction to have occurred, previous exposure to the
drug is necessary. This may have occurred by the patient receiving the
administration, based on variation of hepatic circulation of the
antibiotic in beef, milk, or poultry products where the uncontrolled use drug associated with the two mechanisms of administration. leaves a residue of the antibiotic in food products. Myth #2: Doses & Duration of Antibiotic Treatment
Should be Nonspecific & Variable for Most Odontogenic

Myth #1: Antibiotics are Not Harmful
 It has been estimated when given amoxicillin that (Bigby M et al, 1986; Saxon A et al 1987; Doern GV et al INAPPROPRIATE DOSING of an antibiotic can result in
INADEQUATE CONCENTRATION of the drug at the site of the
1 in every 10 patients develops a rash,
1 in every 10,000 develops anaphylactic reactions, and
1 in every 100,000 dies from an allergic reaction [12–14].
 This practice can promote recurrence of infections and development of  Two types of allergic reactions can arise.
resistant bacterial strains:
 An acute allergic response or an anaphylactic reaction occurs within 30
As vulnerable microorganisms die, the number of surviving microbes
minutes of receiving the drug and the reactions include bronchoconstriction,
urticaria, angioedema, and shock.
increases, making each successive bacterial generation better equipped
Treatment of this type of reaction involves the administration of epinephrine, antihistamine, and possible corticosteroids.
to resist future antibiotic challenges.
Delayed allergic responses take longer than 2 hours to develop and demonstrate
This selection process accelerates when the drugs are administered in mild skin rashes, glossitis, and local inflammatory reactions. doses small enough to allow stronger bacteria to survive the
antibiotic assault.
Therefore, antibiotic therapy should not be prescribed unless
Eventually, strains of bacteria are created that can resist antibiotic
justification for the need is warranted!
Myth #2: Doses & Duration of Antibiotic Treatment
Myth #2: Doses & Duration of Antibiotic Treatment
Should be Nonspecific & Variable for Most Odontogenic
Should be Nonspecific & Variable for Most Odontogenic
 In an average size patient with an odontogenic infection serious enough to
PATIENT COMPLIANCE is another complication in effective
warrant antibiotic therapy, there is little indication for the use of doses of
penicillin as low as 250 mg.
 The drug may be too expensive or not covered by a third party payer  500 mg of penicillin is the lowest dose that should be prescribed for an
(insurance) or unavailable in Bahrain and the prescription remains  INADEQUATE DURATION of the therapy or overdosing of the antibiotic
Dosing frequency may be complicated.
can also result in damaging the host response and producing toxic effects.
 The compliance issue most often observed is missed doses after
 A rule of thumb when prescribing is that the antibiotic should last for 3 days
clinical symptoms have subsided.
after the patient's symptoms have resolved.
 Another challenge to compliance is the untoward or unexpected
 Treatment of most odontogenic infections requires an average of 5–7 days of
side effects that can occur when taking antibiotics.
therapy; however, treatment of severe infections or immunocompromised
patients' therapy may be of longer duration.
 In all these cases, mutated microbes can flourish and cause serious Myth #3: Antibiotics are Always Indicated When
Myth #3: Antibiotics are Always Indicated When
Treating Dental Pain (Odontalgia)
Treating Dental Pain (Odontalgia)
 Irreversible pulpitis is a result of severe inflammation of
 Pain is often caused by the release of these mediators that lower
the pulp system.
pain thresholds and causes spontaneous firing of sensory nerves.
 Pain of irreversible pulpitis may be sharp, dull, localized, or
 A large quantity of inflammatory mediators and neuro- diffuse, and may last minutes to days. peptides are present, which results in vascular
permeability and elevated capillary pressure.
 Chemo-mechanical removal of the pulpal tissue is the treatment of  Because of the hard tissue in which the pulp is encased
and its low-compliance environment, the pulp is unable
 An old but often popular idea was the use of intra-canal
to neutralize these mediators. medicaments to help alleviate the patient's pain complaint. This
concept can be dismissed as it is useless.

Myth #3: Antibiotics are Always Indicated When
Myth #4: Clindamycin is a First Line
Treating Dental Pain (Odontalgia)
Drug for Infections
Cleaning and shaping of the root canal with the use of sodium
 Clindamycin is an antimicrobial reserved for anaerobic, later
hypochlorite, a dry cotton pellet, and temporization of the access is the stage odontogenic infections.
desired treatment (Hasselgren G et al, 1989)
 It exhibits bacteriostatic activity, thereby inhibiting protein  Odontectomy may be indicated if the tooth is deemed to be non-
Appropriate analgesics may be indicated but antibiotics are not.
Clindamycin should be considered ONLY as the first line of
choice if the patient has had an allergic reaction to penicillin or
 The patient's condition should improve rapidly once the source of the if it can be determined that an osteomyelitis caused by anaerobic infection is eliminated. If the problem persists, consultation with a microbes is present – It is an excellent choice for treating serious specialist may be warranted. intraosseous infections (Sabiston CB at al, 1974) Myth #5: If a Periapical Radiolucency, Sinus
Myth #4: Clindamycin is a First Line
Tract, Fistula, or Localized Abscess is Present,
Drug for Infections
Antibiotics are Always Indicated
 Clindamycin has less antigenic potential than penicillin, but has  A periapical radiolucency, sinus tract, or fistula indicates a NECROTIC
a slightly higher incidence of gastrointestinal adverse effects PULP – a vital pulp cannot exist with any of these objective signs.
caused by the overgrowth of Clostridium difficile. Because there is no significant vascularization to necrotic canals or
abscesses, the effectiveness of antibiotic therapy is highly
 Recent studies show that colitis is a possible adverse effect of
questionable – therapeutic concentrations of an antibiotic at the site of most antibiotics, especially broad-spectrum penicillins and
the infectious process cannot be obtained.
 A localized abscess (swelling) begins from the necrotic debris in the
 This condition is often observed in recently hospitalized elderly root canal and diffuses into the surrounding bone at the apex of the
patients who have had previous abdominal complaints and tooth, resulting in a swelling or sinus tract formation.
received high doses of an antibiotic. Myth #5: If a Periapical Radiolucency, Sinus
Myth #6: Antibiotics Must Be Given for
Tract, Fistula, or Localized Abscess is Present,
Several Days Before Implementation Of
Antibiotics are Always Indicated
Surgical Treatment
Controlled clinical trials using penicillin, placebo, and neither
 The polymicrobial environment of odontogenic infections persists
medication in patients presenting with pulpal necrosis and periapical until the source of the irritation is removed.
pain or localized swelling showed no differences between groups in
the course of recovery or symptoms after debridement of the root
 Dental treatment establishes a favourable environment to the
canal system (Fouad A et al, 1996) host to alleviate the disease.
Local dental treatment is most important in resolving the
 The key to successful resolution of the infection is initial drainage
infection. Root canal treatment or extraction if the tooth is not
of the infection coupled with either thorough chemo-
restorable accomplishes the removal of the irritants and drainage of
mechanical debridement of the root canal system or
the swelling. Incision and drainage is indicated if there is no drainage
extraction of the tooth or as an emergency measure until such time
obtained from the tooth or tooth socket.
that definitive dental therapy can be implemented. Myth #6: Antibiotics Must Be Given for
Myth #6: Antibiotics Must Be Given for
Several Days Before Implementation Of
Several Days Before Implementation Of
Surgical Treatment
Surgical Treatment
 The vast majority of localized odontogenic infections
 It is appropriate however to administer oral antibiotics
can be SUCCESSFULLY treated by appropriate dental
approximately 1 hour before surgical therapy - as it
treatment ALONE.
disrupts vascular supply to the infected area.  Even Medically compromised patients who present with  Any time differential greater than 1 hour between
dental pain, sinus tracts, radio-lucencies, apical
administration of oral antibiotic and surgical therapy is periodontitis, or localized intraoral swellings DO NOT
not warranted.
routinely require antibiotics (Fouad A et al, 1996)
If the antibiotic is administered parenterally, tissue
levels adjacent to the infection are established in much less than 1 hour. Myth #7: Indurated Soft Tissues Means
Myth #7: Indurated Soft Tissues Means
Drainage is Not Indicated
Drainage is Not Indicated
DO NOT wait until a swelling becomes soft or
 If soft tissue swellings (cellulitis) are left untreated,
fluctuant before incising and draining.
infection can spread to adjacent facial spaces resulting in serious consequences such as:  Diffuse fluctuant or indurated soft tissues are a more
 airway compromise, severe manifestation of the localized abscess.
 sepsis, blindness,  mediastinal involvement, and  Surgical therapy (root canal treatment or extraction) is
indicated primarily if the aetiology is a necrotic tooth. If  Fluctuant
adequate drainage is NOT accomplished, soft tissue
immediately when incised, whereas a more indurated
incision and drainage may be indicated.
swelling results in small quantities of blood and serous
Myth #7: Indurated Soft Tissues Means
Myth #8: Over-prescription of Antibiotic
Drainage is Not Indicated
Therapy Does not Occur in Dentistry
 Draining both types of swellings releases pressure from
Overuse and improper use of prescription drugs by dentists has
the area and facilitates good recovery by: been well documented.

 providing oxygen to an anaerobic environment,  The USA national Centres for Disease Control and Prevention estimate  increasing blood circulation, and that approximately one third of all outpatient antibiotic prescriptions  thereby optimizing host defence mechanisms. are unnecessary.  A culture and sensitivity should be obtained when
Nearly $23 billion worldwide has been spent on antibiotics in the last
draining an infection, not to guide the initial antibiotic year (Slavkin H et al, 1997) selection, but to be available should the empiric antibiotic  Approximately 10% of antibiotics are now rendered INEFFECTIVE
therapy used fail. (Slavkin H et al, 1997) Myth #8: Over-prescription of Antibiotic
Therapy Does not Occur in Dentistry

The patient who demands to leave the  Chemoprophylaxis is the use of antimicrobial agents to
prevent an infection.
appointment with a prescription in hand may drive the misuse of antibiotics.  In dentistry, this can arise in two contexts: the prevention of an infection at or near the site of a
The reality is that appropriate dental treatment, surgical operation or analgesic therapy, and education of the patient will at a different site elsewhere in the body.
alleviate the patient's symptoms and build trust in  With respect to the latter, the main issues relate to the the doctor-patient relationship. prevention of infective endocarditis and infection in patients with hip and other joint prostheses. Infective Endocarditis
Infective Endocarditis
Infective endocarditis is a microbial infection of the endocardial
 The overall global incidence of infective endocarditis is difficult to
surfaces usually involving the heart valves.
determine – In the UK, approximately 1,500–1,800 cases are reported annually.
In the USA, there is a reported incident rate of 11.6 per 100,000 person-years
 The infective organisms are usually bacteria, but infective endocarditis can also (Berlin JA et al, 1995) be caused by fungal species. The mortality rate of infective endocarditis, even with antibiotic therapy, is
 Infection on a compromised endocardial surface (especially damaged or
30% (Netzer RO et al, 2000) prosthetic heart valves) gives rise to the formation of vegetations.
 It is interesting to note that the prevalence of infective endocarditis has
remained consistent, even after the introduction of antibiotic prophylaxis in
 These vegetations proliferate and eventually can destroy the valves.
the 1940s (Bayliss R et al, 1983) – Note/ dramatic RISE in the number of patients
receiving artificial heart valves AND in addition to a range of cardiac
 Embolism of fragments of the vegetations can damage organs and tissues
conditions, other risk factors for infective endocarditis include drug abusers, including the brain, lung, and coronary arteries. alcoholics, and patients with poor oral health. Microbiology of Infective Endocarditis
Dental-Induced Bacteremia
 Microorganisms most frequently cited include S. aureus and oral
 Many dental procedures, especially those involving dento-gingival
streptococci (especially α-hemolytic viridans streptococci).
manipulation, will give rise to a bacteremia.
The primary event in the pathogenesis: is bacterial adherence to
 The more inflamed the gingival tissues, the greater the risk and
damaged heart valves. This event is completed within minutes during
magnitude of bacteremia.
transient bacteremia and involves valve tissue and bacterial factors.
 Many oral hygiene procedures and even chewing can result in  The second stage: involves persistence and growth of the bacteria
significant bacteremia of similar magnitude to the occurrence after
within the cardiac lesion and the formation of vegetations. certain dental procedures (Roberts GJ et al, 1999)  After valve colonization, the infecting microorganisms must survive and
Bacteremia arising from dental treatment, oral hygiene practices, or
avoid host defenses. A key event in this process is maturation of the
even chewing are of low-grade intensity (1 × 101 to 2 × 102 colony-
vegetation within which the bacteria can become fully enveloped. forming units ⁄ ml of blood) and of short duration (30–600 seconds).
Dental-Induced Bacteremia
Dental-Induced Bacteremia
 For the dental procedure to be considered then this has to have  Roberts (1999), evaluated the evidence of dental-induced bacteremia been completed or carried out within 14 days of the diagnosis
and infective endocarditis – Three conclusions :
of infective endocarditis.  gingival bleeding is a POOR predictor of dental-induced bacteremia,
 the intensity of bacterial inoculae arising from dental operative
procedures is LOW when compared to the high intensity needed for a
Often dentistry is blamed for infective endocarditis because
90% infective dose in experimental animals. cardiologists just ask patients in whom infective endocarditis is  The procedures most often regarded as requiring antibiotic
suspected whether they have received or visited the dentist prophylaxis DO NOT carry the greatest risk of cumulative bacteremia.
The latter arise from chewing and various oral hygiene practices.
If laws of probability are applied to this data then either patients
 It may well transpire that spontaneous bacteremia may be at risk from infective endocarditis should be on continuous
MORE responsible for infective endocarditis than dental
chemoprophylaxis or the need to provide cover for dental
treatment is grossly overstated!
Chemoprophylaxis and the at Risk
Dental-Induced Bacteremia
 Further evidence to support this finding comes from an analysis of
 There is debate between the various governing bodies as to what
cases whereby dental treatment has been implicated as the cause:
underlying cardiac condition requires chemoprophylaxis.
Oral streptococci cause approximately 50% of all infective endocarditis
 Each country has slightly different guidelines, but many have followed  Similarly, only 15% of patients, where infective endocarditis has been
those issued by the American Heart Association in 1997 and 2007.
diagnosed, report medical or dental treatment within the previous 3  In 2006, the British Society of Antimicrobial Chemotherapy published
 It has been estimated that 4% or less of all infective endocarditis cases are
their guidelines for the prevention of endocarditis and details. related to dental treatment induced bacteremia (Bayliss R, 1983; Guntheroth WG, 1984). Whether such bacteremia arises from dental treatment or is
 There are many similarities between the two sets of guidelines, in spontaneous in nature is not discernible. It has been suggested (Oakley CM,
particular their recommendations for the cardiac conditions that
1986) that if spontaneous random bacteremia cause 96% of all cases of
require antibiotic chemoprophylaxis. Differences do exist with respect
infective endocarditis, then these bacteremia, as opposed to those arising to the dose of amoxicillin.
from dental treatment, may also have caused the remaining 4%.
American Heart Association Guidelines on
American Heart Association Guidelines for
Cardiac Conditions for when
Dental Procedures for which Endocarditis
Chemoprophylaxis for Dental Procedures is
Prophylaxis is Recommended
American Heart Association Regimens
For A Dental Procedure


CHIMIE NOUVELLE N° 117 - décembre 2014 Joséphine K. NTUMBA(1)(2), Kalulu M. TABA(2), Raphaël ROBIETTE(1)*(1) Institut de la Matière Condensée et des Nanosciences (IMCN), Université catholique de Louvain, Place Louis Pasteur 1 bte L4.01.02, B-1348 Louvain-la-Neuve, Belgique. Tel: +32 (0)10 47 91 76, Fax: +32 (0)10 47 42 68, [email protected] Département de Chimie, Université de Kinshasa, P. O. Box 190, Kinshasa


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