1. Role of Antibiotics In Exodontics
Dr.V.RAMKUMAR
CONSULTANT DENTAL &FACIOMAXILLARY SURGEON
REG NO:4118 -TAMILNADU –INDIA( ASIA)
2. History
• Pasteur & joubert ( 1877)
• Modern era (1936) sulfanilamide
• Golden year (1941) penicillin.
3. Definition
• Antibiotics are substances produced by
microorganisms, which suppress the growth
of or kill other microorganisms at very low
concentrations.
4. Classification
1. On the basis of preparation :
i. Naturally occurring, e.g. from fungi, e.g. penicillins, cephalosporins,
erythromycin, tetracycline, chloramphenicol, and aminoglycosides,
etc.
ii. Synthetic, e.g. sulfonamides.
2. On the basis of family:
i. Penicillins
ii. Cephalosporins
iii. Sulfonamides
iv. Tetracyclines
v. Aminoglycosides
vi. Macrolide
5. 3. On the basis of spectrum of activity:
i. Narrow: penicillins
ii. Broad: ampicillins, tetracyclines.
4. On the basis of effect:
i. Bacteriostatic: erythromycine, tetracycline, sulfonamide,
etc.
ii. Bactericidal: penicillins, cephalosporins, etc.
6. 5. On the basis of their effect on Gram-positive or
Gram-negative bacteria:
i. Antibiotics acting on Gram-positive bacteria: penicillins,
cephalosporins, erythromycine, bacterim, tetracycline,
gentamicin, etc.
ii. Antibiotics acting on Gram-negative bacteria: penicillin
acts on gonococci.
7. 6. On the basis of systems:
i. Urinary tract:
– Nalidixic acid: acts on kidney and urinary
bladder
– Furadantin: acts on bladder
i. Skin : Neomycin, bacitracin, polymyxin.
ii. Orally (locally): neomycin, streptomycin.
8. Antimicrobial vs Antibiotic
Confusion regarding antimicrobial
and antibiotic !!
Mechanisms by which antibiotics may
inhibit growth and multiplication :
Alteration of cell membrane permeability
Alteration in synthesis of cellular component
Inhibition of Cellular metabolism
9. Sites of action
Inhibiting formation of the bacterial cell wall
Inhibiting bacterial protein synthesis
Inhibiting nucleic acid synthesis
Altering the permeability of cytoplasmic membranes
10. Factors influencing the efficacy:
Drug binding
Protection of pathogens
Total bacterial load
Effectiveness of host defenses
Pathogens in the periodontal tissues, root canals and other oral
sites not affected by the therapy
Systemic and Topical antibiotics
What to use and Where ??
11. Rationale of antibiotic usage
Microbial etiology
Concept based on the premise….
Patients who do not respond to mechanical therapy
Thus the concept of antibiotic therapy
centers upon the pathogenic microbiota,
the patient and the drug
12. 3 ways : Empirical therapy
Definitive therapy
Prophylactic
-against specific organisms
-high risk
-In general
Uses in dentistry and their side effects
13. Choice of an antibiotic :
Patient factors :
1.Age
2. Dose modification :
3. Local factors : Pus
Hematomas
Ph
Anaerobic environment
4. Drug allergy
5. Impaired host defence
14. Organism related considerations:
• Clinical diagnosis itself directs…
• Choice
Combination therapy
Synergism
To reduce severity or incidence of adverse effects
Prevent resistance
To broaden the spectrum of antibiotic action
“Good decisions improve the chances of successful outcomes”
16. QUINOLONES
• Synthetic
• Having a quinolone structure
• Primarily active against Gm–ve bacteria
• Newer fluorinated compounds also inhibit
Gm+ve ones
• 1stmember
nalidixic acid in mid 1960s
17. Fouoroquinolones
• Quinolones antimicrobials having one or more
fluorine substitution.
• First generation Fouoroquinolones –
• Second generation Fouoroquinolones -
Norofloxacin Ofloxacin
Ciprofloxacin Pefloxacin
Lomefloxacin Levofloxacin
Sparfloxacin Gatifloxacin
Moxifloxacin
18. Beta Lactam Antibiotics
These are antibiotics having a β-lactam ring.
The two major groups are pinicillins and
cephalosporons.
19. PENICILLINS
• Penicillin was the first antibiotic to be used
clinically in 1941. it is a miracle that the
least toxic drug of its kind was the first to
be discovered. It was originally obtained
from the fungus Penicillium notatum, but
the present source is a high yielding mutant
of P.chrysogenum.
20. Semisynthetic Penicillin
Classification –
1. Acid resistant alternative to penicillin G phenoxymethyl
penicillin (Penicillin V).
2. Penicillinase resistant penicillins Methicillin, Oxacillin,
Cloxacillin.
3. Extended spectrum penicillins
a) Aminopenicillins: Ampicillin, Bacampicillin, Amoxicillin.
b) Carboxypenicillins: Carbenicillin, Carbenicillin indanyl,
Carbenicillin phenyl (Carfecillin), Ticarcillin.
c) Ureidopenicillins: Piperacillin, Mezlocillin.
d) Micillinam (Amdinocillin).
β-lactamase inhibitors Clavulanic acid Sulbactam.
21. Cephalosporins
• These are a group of semisynthetic
antibiotics derived form ‘cephalosporin-C’
obtained from a fungus Cephalosporium.
They are chemically related to penicillins;
the nucleus consists of a β-lactam ring fused
to a dihydrothiazine ring.
26. Aminoglycoside Antibiotics
These are a group of natural and semisynthetic antibiotics
having polybasic amino groups linked glycosidically to two or
more aminosugar (streptidine,2-deoxy streptamine, garosamine
residues).
28. MACROLIDE ANTIBIOTICS
• These are antibiotics having a macrocyclic
lactone ring with attached sugar.
Erythromycin has been in use from the
1950s, Roxithromycin, Clarithromycin and
Azithromycin are the recent additions.
32. Principles for choosing ANTIBIOTICS!!!!!
• IDENTIFICATION OF THE CAUSATIVE ORGANISM
• DETERMINATION OF ANTIBIOTIC SENSITIVITY
• SPECIFIC, NARROW SPECTRUM – Ab
• LEAST TOXIC Ab
• Pt’s DRUG HISTORY
• BACTERICIDAL RATHER THAN
BACTERIOSTATIC
• Ab WITH PROVEN HISTORY OF SUCCESS
• COST OF Ab
+
+
+
+
34. Causes of failure
• Inadequate surgical treatment
• Depressed host defence
• Prence of foreign body
• Antibiotic problems
– drug not reaching infection
– Dose not adequate
– Wrong bacterial diagnosis
– Wrong antibiotics
35. Classification of wounds ( CCSC )
Class I (Clean) – Non-Traumatic or surgical
Class II (Clean contaminated) – Fresh
Class III ( Contaminated )
Class IV ( Dirty )
36. Class I – No Antibiotics
Class II – Rarely / depressed host, prosthetic
device infection prolonged surgery
and reduced blood supply.
Class III & IV - Antibiotics
Whento use?????
38. Indications of prophylactic Ab
• Endocarditis
• Valvular heart diseases
• Total joint replacement
• ESR
• Prosthetic valves
• DM
• Leukemia
• COL
• Immunosuppressed patients
39. Prophylactic regimens for dental procedures
Situation Antibiotic Regimen
• Standard general
prophylaxis
Amoxicillin Adults, 2.0 g; children, 50
mg/kg orally one hour
before procedure
• Can not use oral
medications
Ampicillin Adults, 2.0 g IM/IV;
children, 50 mg/kg IM/IV
within 30 minutes before
procedure
40. Contd..
• Allergic to
penicillin
Clindamycin
or
Cephalexin
Cephadroxil
or
Azithromycin
or
Clarithromycin
Adults, 500 mg; children, 20 mg/kg
orally one hour before procedure
Adults, 2.0 g; children, 50 mg/kg
orally one hour before procedure
Adults, 500 mg; children, 15 mg/kg
orally one hour before procedure
• Allergic to
penicillin and
unable to
take oral
medications
Clindamycin
or
Cephazolin
Adults, 600 mg; children, 15 mg/kg IV
one hour before procedure
Adults, 1.0 g; children 25 mg/kg IM/IV
within 30 minutes before procedure
42. Misuse of antibiotics :
Inappropriate antibiotic
Failure to take the entire prescribed course
Saving antibiotics for a future illness
Sharing or using someone else’s medicine
Era of antibiotic on demand
False sense of security
Over the counter availability (self medication)
43. Is antibiotic misuse a serious problem ?
Antibiotic misuse can lead to the development of
antibiotic-resistant bacteria.
Misusing antibiotics means they may not be effective
when needed to treat an infection in the future.
44. Abuses :
Humans have ignored a clear warning that
excessive or abuse of antibiotics would lead to
a world filled with human carriers of bacteria
resistant to known antibiotics
Broad spectrum and long courses of therapy
Prophylactic use for simple surgical procedures
“When in doubt cover”
Well defined limited infections
Pain
“Selective pressure phenomenon”
45. Emerging Antimicrobial Resistant
Organisms: The Global Problem of
Antibiotic Misuse
Adaptations (product of selection)
Acquisition and transmission of antibiotic resistance
(horizontal gene transfer)
Mechanisms:
1. Mutation
2. Destruction or inactivation
3. Efflux
47. How to prevent abuse ??
Sufficient risk of infection morbidity
Bactericidal antibiotics are preferred …
Narrow spectrum antibiotic effective
Dosages should not be reduced.
Aggressive antibiotic protocol in immuno- compromised
patients
Close up follow up of patients with infection
Difficult chronic and sub acute infections
48. How to prevent antibiotic abuse
Most appropriate
Maintain high enough levels of the drug
No “Just in case”
2 or more drugs to be administered
Restrict use of drugs
Strictly regulate the amplification of drug resistance
49. Policy for antibiotic use
Surveillance systems
Educational and Compliance programs
Solutions for bacterial resistance :
Research
Quality control in pharmaceutical production
Other modalities : “Decoy molecules”
