Download Sheet #7 / Dr.Ibraheem Abu Tahoun / Mahmoud

Mahmoud Hussien
Cons Sheet #7
Endodontic Pharmacology
-Starting with the discovery of Pencilline by Fleming which start the era of antibiotic which are
the tools for control infection in medicine and dentistry.
-We should be able to recognize the bacteria which cause the infection to determine the most
appropriate treatment to overcome this infection successfully.
-Except in immunocompromised patient, antibiotics don’t cure patients, patients cure
themselves .So antibiotic will control the infection while the body begin to heal itself.
-Dentistry is a part of international antibiotic problem, so we need a clear advice on how to
match pharmacology to microbiology, so we find confusion on prescribing the antibiotic.
-It seems that habits, beliefs and clinical impressions play an important role in prescribing the
antibiotic, so we aren’t based on the science regarding prescribing antibiotics.
-We have a problem regarding endodontic infection and its complications, as in the presence
of infection or inflammation the ability of the antibiotics to reach bacteria in therapeutic
concentration will be diminished, as the inflammatory environment will diminish the efficacy of
the antibiotic, because this environment will not allow the antibiotic to reach infection site in a
concentration which is sufficient to cure the patient.
-As a general role Debridement (which includes mechanical instrumentation and disinfection)
is a prerequisite for wound repair.
-Pain and swelling are the side effects and complications of pulpal infections, so we aim to
eliminate the causative agent and zones of infections which found inside the root canal and the
microbes that continue apically within root canal.
-Up to 60% of human infections resolve spontaneously by host defense alone without any
antibiotic cover once the causative factors are removed and this implied to pulpal infection, so
the majority of endodontic infections will resolve without antibiotic intervention if the
infection is properly managed, as a result, endodontic therapy alone is usually sufficient to
relieve the pulpal infection if done properly.
Mahmoud Hussien
Cons Sheet #7
-Conclusion: antibiotics cannot effect bacteria confined to necrotic pulp tissue within root
canal system nor can systemically administered antimicrobial reach the reservoir of bacteria
confined within periapical abscess.
-Antibiotics aren’t indicated to treat pain related to:
1- Pulpits
2- Uncomplicated edema:
* Draining sinus tract
* Localized intraoral swelling
* Symptomatic apical periodontites.
-so its important to manage the symptoms and disease before prescribing the antibiotic, and
for pulpal infection this is achieved by Drainage and Debridement.
-Benefits of Drainage:
1- It stimulates healing
2- Improves the circulation
3- Eliminates bacteria
4- Relives the pressure
-There is no definite positive correlation between bacterial strains or their by products and any
specific endodontic disease or symptoms as in the root canal we have a mud of bacteria ( up to
90 types of bacteria cause the pulpal infection, so its polymicrobial infection) and this make
previous disease more resistant to antibiotic therapy, but its possible that certain combinations
of microbial interact with the host to produce certain pathological state.
- Types of microbial strains that are resistant to antiseptics in the root canal:
1- Streptococaus faecalis
2- Staphylcocaus aureus
3- Peptostrepto coccus
Mahmoud Hussien
Cons Sheet #7
-Its recommended to do antibiotic susceptibility test (which will reflect the cause of infection
in the patient) to be a guide for prescribing the appropriate drug therapy as not all infectious
cases caused by the same types of bacteria, so its important that the treatment should be
based on the particular facts of the case and the true microbial status of disease.
- However, culturing the root canal tissues rarely recommended in the endodontic infection,
and even we do culturing, antibiotic cover should begin immediately.
- The root canal can act as a pathway for the host sensitization, which mean that many of the
clinically disrupted reaction (that observed during the endodontic therapy) may be a result of
an allergic of hypersensitivity reaction which means if the allergen, that cause endodontic
infection, isn’t bacteria then the antibiotics aren’t the choice for treatment because the cause
of infection is the immune response not bacteria. So what histologically appears as an
inflammatory response will exclude the use of antibiotics.
-Occasional pain or discomfort which usually appears following endodontic infections will
resolves spontaneously few days after treatment (assuming that you did a proper root canal
treatment ) so the treatment in this case in No treatment just we reassure the patient to gain
his confidence and to break the psychological component of the pain.
- Retreatment is indicated in persistent painful cases if there is inadequate root canal
treatment.
-When to use antibiotics?
Generally there is no rule when to prescribe the antibiotic, but usually the choice depends on
clinical experience, the suspected bacteria pathogen, allergic reactions and the choice of
bactericidal or bacteriostatic agent.
-Antibiotics are indicated in the following states:
1- Acute pulpal alveolar cellulites
2- Active progressive infection
3- Immunocommpromised patients
-Main possible etiological factors for Cellulites:
1- Gram negative microbes
2- Extra radicular biofilm
Mahmoud Hussien
Cons Sheet #7
3- Pencillinase-producing microbes
4- Obligate and aerobic microbes
So in case of patient with diffuse cellulites we should follow the following steps:
1-Debridement of pulp space ( complete debridement which include the whole pulp space
and length)
2-Placement of calcium hydroxide
3-Surgical incision for drainage
4-Prescribing the appropriate antibiotic (whether IV,IM or Systematically antibiotics)
Note: If the initial antibiotic treatment is ineffective, and after about 24-72 hours the patient
state deteriorate, in this case we add Metronidazole to the original prescribed antibiotic, this
will be more effective as Metronidazole will enhance the affectivity of the original antibiotic.
- If the patient, who has cellulites, appears with signs of toxemia, we should consider the
following for treatment:
1-Hospitalization
2-IV + IM injections
3-Culture (to determine the exact cause of toxemia)
(2% of the patient with cellulites might require hospitalization)
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-Based on antibiotic culturing data we can determine the appropriateness of the antibiotic
-Types of antibiotic that might be required in case of endodontic infections:
1-Pencillin VK:
* First line of antibiotics for endodontic infection and most of dental infection
*Dose:
-Loading dose= 1000 mg (equals to Two tablets of the drug)
Mahmoud Hussien
Cons Sheet #7
-Maintenance dose= 500 mg (1 tablet every 6 hours)
*Side effects:
2% of the patients might have allergy toward Penicillin VK (fear of anaphylaxis)
2-Clindamycin:
*Usually used in patient with allergy to pencillin.
*Dose:
-loading dose= 600 mg
-Maintenance dose= 300 mg = 1 tablet every 12 hours (in patient with deteriorated state, it
can be given every 8 hours for 2-3 days after the treatment)
*Side effects:
Pseudomembranous colitis (inflammation of colon that occurs in some patient taking certain
types of antibiotics)
3-Augmentin:(amoxicillin clavulanate)
*The most effective antibiotic in recent tests.
*It should be reserved for sever infectious state
*Dose:
1 tablet of 625 mg every 8 hours
4-Metronidazole:
*Can't be used alone, usually used with the original antibiotic
*Dose:
-Loading dose=1000 mg
-Maintenance dose= 500 mg every 6 hours
Mahmoud Hussien
Cons Sheet #7
-Patient monitoring:
* Most oral infections are treated successfully and clinically without identification of the
causative factors.
*It is the responsibility of dentist to monitor clinical progress of the oral infection
*If the response and recovery are slow, all aspects of the treatment should be examined.
-Dosage of antibiotic:
All the prescribed antibiotics should start with the loading dose which is 2 times higher than
the maintenance dose
(Loading dose: is the initial higher dose of the drug that is given at the beginning of the course
of treatment -to achieve rapid increase and high level of drug in the blood- before dropping
down to a lower maintenance dose )
-Timing
* When antibiotic is indicated so timing is very important, so antibiotic should attack microbes
:
1-During contamination
2-Before colonization
3-Before invasion
After that it becomes more difficult to control spread of bacteria and becomes more difficult to
control the infection.
-Duration of using:
In the past they thought that patient should take the whole course of antibiotic because of the
fear of rebound infection but at 2012 American Association of Endodontisits said that (orofacial
infection don’t rebound if the source of the infection is properly eradicated, so once the
infection resolved antibiotic therapy should be terminated)
Mahmoud Hussien
Cons Sheet #7
-Antibiotic as a prophylaxis:
* Antibiotics might be used as a prophylaxis for medically at risk patient, so to prevent
infective endocarditis under dental treatment it is reasonable to prescribe antibiotic course to
be in the safe side.
*For medically at risk patient its important to preconsult the doctor of that patient to ensure
that patient really in need to take antibiotic as a prophylaxis especially with those having
prosthesis.
-The new dangerous issue is the overuse of antibiotics which produce what is called Superbug
infection (which produces bacteria that more resistant to antibiotic) this make infections
harder to be treated.
-Topical use of antibiotic:
This means that we use antibiotic directly inside root canal, being superior to antiseptic in
disinfection , so they used poly antibiotics (especially penicillin in liquid form) and this were
widely used in endodontics, after that this method avoided because of adverse allergic
reaction and because polyantibiotcs lose the effectiveness very quickly this make their use less
important, but nowadays they re-use the antibiotics but in a different way by using Triple
Antibiotic (Metronidazole,Ciprofloxacin,Minocycline) they put them inside root canal to
achieve disinfection and revascularization.
The most important question, do the root canal need to be sterilized?
-Primarily the answer is No, as every time we do obturation we leave bacteria behind as we
never can achieve complete sterility of canals, so we usually aim to reduce the bacterial
account to a level that can be attack by the host defense system.
-Many of the endodontist use explosive chemicals (such as potassium) to sterilize the root
canal but actually we don’t need this at all.
- During seventies Sodium Hypochlorite was used as irrigant for root canal ( it the best
intracanal irrigant ever used)
-The only intracanal medicament that is permitted to be used in case of multiple endodontic
visits is Calcium Hydroxide, other antiseptics their effectiveness under clinical usage is doubt.
Good luck
Mahmoud Hussien
Cons Sheet #7