Local & Systemic Antimicrobials Flashcards
2 different classifications of bacteria?
bacteriocidal- activley kills bacteria
Bacteriostatic- prevent bacteria from reproducing allows the immune system to take over.
2 classified modes of action of bacteria?
Broad spectrum – active against a large number of organisms e.g. Penicillin, Tetracycline.
Narrow spectrum – only effective against a small range of bacteria e.g. Metronidazole, Erythromycin.
what is local delivery of anti- microbals?
Placed into pockets to kill bacteria and aid in healing of periodontal disease
Contain antibiotics and other antimicrobial drugs
advantages of local delivery of anti-microbals?
Delivered directly to the site of disease activity
Gives enough concentration of drug to reduce pathogenic organisms
Drug levels maintained without high systemic exposure to the drug
Less need for patient compliance
Unlike systemic antimicrobials e.g. 20mg Doxycycline ‘Periostat’ 2x daily for 3mths
A number of pathogenic bacteria remain in the pocket following scaling and root planing why?
because access for instrumentation can be limited
what are the 2 types of local delivery?
Sustained release
Provides drug delivery for less than 24hrs
Controlled release
Provides drug release for greater than 24 hours
types of of topical antimicrobials?
Minocycline gel – ‘Dentomycin’- Bio-absorbable gel
can reduce pocket depths by up to 42%.”
Resorbable (1 day)
3-4 applications at fortnightly intervals
Delivered in a syringe with a blunt cannula
Disadvantage – tends to be washed out by gingival crevicular fluid, requires multiple applications
Metronidazole gel - ‘Elyzol’- 25% metronidazole
Sustained release delivery system, over 24 – 36 hours
Bio-absorbable in 3 days
Several applications needed with syringe and blunt cannula
Initially liquid, becomes solid in pocket
Disposable applicator, enough for 20 teeth
2 applications at weekly intervals
Chlorhexidine chip – ‘Perio chip’ 2.5.mg Chlorhexidine in a biodegradable film of hydrolysed gelatin
Delivers chlorhexidine for at least 7 days (controlled release)
Not associated with the side effects of chlorhexidine e.g. stain/taste disturbance
Cannot be used in pockets less 5mm deep
Isolate the periodontal pocket and dry surrounding area
Hold periochip with a pair of tweezers, so that the rounded end point away from the tweezers
Technique sensitive – temperature of mouth makes chip malleable
Insert into maximum depth of the pocket (flat plastic)
Self-retentive
Resorbable (8 days)
May need to be repeated in 3 months
Doxycycline gel – ‘Atridox’- Atridox
Doxycycline in a bio-absorbable polymer gel
Gel hardens in the pocket
Controlled – release
Released in pocket for a period of 7 – 10 days
8.8% doxycycline
Mixed chairside (liquid polymer and powdered doxycycline), shelf-life is 1 day
Introduce cannula to base of pocket, gradually withdrawn, filling pocket
Injected as a gel that solidifies in contact with moisture
Controlled delivery (retained in the pocket for approx. 10 days)
Tetracycline fibre – ‘Actisite’ Non-resorbable - 25% Tetracycline
Must be secured by sealing pocket orifice with adhesive – Medical grade tissue glue, ie PerioAcryl90
Clinical uses of topical antimicrobials on which patients?
Localised recurrent pockets in a patient during supportive treatment
Non-responding sites following non surgical therapy
Peri-implantitis
Localised suppurating pockets
When to decide to use topical antimicrobials them?
First
Root Surface Instrumentation
Then
Isolated deep pockets greater than 5mm
Well motivated patients with good oral hygiene
advantages and disadvantages of topical antimicrobials?
adv
Minimal side-effects
Avoiding drug resistance/hypersensitivity
Higher concentrations in the periodontal pocket (bactericidal)
Reduced total drug dose
dis adv
Time consuming
Expensive
SYSTEMIC ANTIMICROBIALS
Typically the Antibiotics used as an adjunct to RSD are Amoxicillin and Metronidazole
A typical dosage could be:
Amoxicillin 500mg 3 x day for 7 days + Metronidazole 200mg 3 x day for 7 days- usually for FMD (will follow in later lecture)
