Control of microorganisms by antibiotics
1 / 32

Control of Microorganisms by Antibiotics - PowerPoint PPT Presentation

  • Updated On :

Control of Microorganisms by Antibiotics. Weinberg, chapter 11. Properties of an Ideal Antibiotic. Bacterial specificity Should not produce resistant strains Does not cause allergy or toxicity Does not cause other side effects Does not eliminate normal oral flora Cost effective

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Control of Microorganisms by Antibiotics' - idana

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Properties of an ideal antibiotic l.jpg
Properties of an Ideal Antibiotic

  • Bacterial specificity

  • Should not produce resistant strains

  • Does not cause allergy or toxicity

  • Does not cause other side effects

  • Does not eliminate normal oral flora

  • Cost effective

  • Hence the ideal has not been found!

Antibiotic adjunctive therapies l.jpg
Antibiotic Adjunctive Therapies

  • Treatment of aggressive periodontal diseases, chronic periodontitis, refractory periodontitis

    • Initial identification of pathogens

    • Appropriate antibiotic selection

    • Debridement should be carried out first

  • Systemic antibiotics commonly prescribed:

    • tetracyclines, metronidazole

    • amoxicillin, Augmentin, ampicillin

    • ciprofloxacin, clindamycin

    • Periostat (doxycycline)

Systemic use concerns l.jpg

Common side effects:

Nausea, GI upset



Resistant bacteria

Poor client compliance

May be to broad spectrum

Common oral manifestations:

Black hairy tongue

Oral candidiasis

Systemic Use – Concerns

Controlled release agents l.jpg
Controlled Release Agents

  • Work by suppressing destructive enzymes produced during inflammatory process or suppressing microbes

  • Considered for localized periodontal sites

  • Systems available include:

    • Actisite (tetracycline fiber)

    • Atridox (doxycycline gel)

    • Arestin (minocycline microsphere)

Advantages of controlled release agents l.jpg
Advantages of Controlled Release Agents

  • Client compliance not an issue

  • GCF concentration greater than serum levels

  • Delivery is localized – reduces systemic effects

  • Reduced side effects

Tetracycline l.jpg

  • Clinical Use:

    • Refractory periodontitis

    • Localized aggressive periodontitis

    • Growing trend to use combination therapies – more effective

    • Systemic & local delivery systems

Tetracycline8 l.jpg

  • Mechanism of action:

    • Bacteriostatic, broad spectrum

    • More effective against gram-positive bacteria

    • However, A.a. highly susceptible

    • Non-antibacterial properties:

      • Inhibits production & secretion of collagenase

      • Inhibits bone resorption

Tetracycline9 l.jpg

  • Mechanism of action:

    • Antibacterial properties:

      • Inhibits growth & multiplication of bacteria

  • Dosage:

    • 250 mg for 2 weeks

Tetracycline side effects l.jpg

Intrinsic tooth staining

GI upset, abdominal pain

Diarrhea, vomiting

Fungal overgrowth

Resistant bacterial strains

Interferes with bactericidal activity of penicillin's & cephalosporins

Reduces effect of BCP

Tetracycline – Side Effects

Actisite periodontal fiber l.jpg
Actisite Periodontal Fiber

  • Clinical use:

    • Pockets measuring  5 mm, bleed on probing

    • Localized treatment for sites that have not responded to previous mechanical therapy

  • How supplied:

    • Cartons of 4 or 10 fibers

    • 23 cm in length

    • 12.7 mg tetracycline hydrochloride

    • Stored at room temperature

Actisite l.jpg

  • Application:

    • Treat one quadrant or one side of mouth at a time

    • Client may request anaesthesia

    • Fiber inserted into pocket (circumferential or not)

      • Takes about 10 minutes/tooth

    • Some control of saliva

    • Should contact pocket base

Actisite13 l.jpg

  • Application:

    • Sealed in place with adhesive

      • Apply in thin even line along gingival margin

      • Surgical dressing not necessary but has been used

    • Removed 7-10 days after placement

      • Curette and/or cotton pliers

      • Fiber comes out in mass or pieces

      • Debride areas as necessary

    • Tissue may appear red following removal

Actisite14 l.jpg

  • Adverse effects:

    • Discomfort

    • Local erythema

    • Little systemic reaction

    • Used with caution in client with history of candidiasis

    • Application around 12+ teeth may result in oral candidiasis

Actisite15 l.jpg

  • Client instructions:

    • Avoid brushing & flossing

    • Use antimicrobial rinse

      • Use of CHX may have syngerstic effect

    • Avoid hard or crunch foods, stick foods, chewing gum

Actisite16 l.jpg

  • Clinical Efficacy:

    • Reduction in bleeding on probing and pocket depth

      • More significant reductions in deeper pockets

    • Reduction in periodontal pathogens

    • Effects of fiber on bone loss, tooth mobility or tooth loss not established

Metronidazole l.jpg

  • Clinical use:

    • Refractory periodontitis (when combined with amoxicillin or Augmentin)

    • Necrotizing ulcerative gingivitis

    • Moderate – severe periodontitis

    • Aggressive periodontitis (LAP) when combined with amoxicillin or Augmentin

    • Following perio surgery if barrier membranes in place – suppresses P.g.

Metronidazole18 l.jpg

  • Mechanism of action:

    • Bactericidal antimicrobial

    • Disrupts DNA synthesis leading to cell death

    • Selectively kills bacterial associated with periodontal disease

    • Susceptible bacteria include:

      • Fusobacterium, Bacteroides

      • Peptostreptococcus

      • Treponema, Campylobacter

      • Veillonella

Metronidazole side effects l.jpg

GI disturbances


Dry mouth

Candida infections

Metallic taste

Nausea, diarrhea


Avoid alcohol when taking: acute nausea, headache, vomiting

May decrease effects of BCP

Metronidazole – Side Effects

Metronidazole20 l.jpg

  • Clinical Considerations:

    • GCF concentrations > blood serum levels

    • When combined with oral hygiene & debridement = beneficial effect on periodontitis

      • Periodontal surgery may not be necessary

    • Doxycycline may be substituted for metronidazole

      • If client can’t abstain from alcohol

Before aftertreatment with metronidazole l.jpg

Probing depth of 6 mm

Tissue shrinkage & recession

Before & AfterTreatment with Metronidazole

Before after treatment with metronidazole l.jpg

6 mm probing depths

Surgery has not been required

Before & After Treatment with Metronidazole

Metronidazole23 l.jpg

  • Some evidence of bone gain – client 2.5 years after initial debridement and use of metronidazole

Metronidazole24 l.jpg

  • Dosage:

    • 250 mg tid for 7-10 days

    • 500 mg bid for 1-2 weeks

  • Doxycycline

    • 100 mg per day or BID

  • Metronidazole and amoxicillin or Augmentin

    • 250 mg (of each) TID for 7-10 days

Arestin l.jpg

  • Clinical use:

    • Periodontitis with pockets  5 mm

  • How supplied:

    • Box containing 2 trays each containing 12 cartridges

    • Cartridge contains 1 mg of minocycline (semisynthetic tetracycline derivative) microencapsulated in Poly dry powder

    • Cartridge inserted into a cartridge handle

Arestin26 l.jpg

  • Preparing for Arestin

Premeasured, premixed, no refrigeration necessary

Arestin27 l.jpg

  • Mechanism of action:

    • Broad spectrum

    • Bacteriostatic

    • GCF levels maintained at high levels for at least 14 days

Arestin28 l.jpg

  • Application:

    • Insert tip to base of periodontal pocket

    • Expel powder into pocket

    • Bioadhesive microspheres activate & adhere on contact with moisture

    • Cartridge contains enough Arestin for one periodontal pocket

    • Clinical trials: 30 sites treated in less than 10 minutes

    • Dressings or adhesives not required

Arestin29 l.jpg

  • Adverse effects:

    • Headache

    • Pain

    • Mouth ulceration

    • Slu syndrome

    • Stomatitis

Arestin30 l.jpg

  • Client instructions:

    • Do not eat hard or sticky foods for 1 week

    • Postpone brushing for 12 hours

    • Do not use interproximal cleaning aids for 10 days

Arestin31 l.jpg

  • Clinical efficacy:

    • 27,000 sites treated, n=748

Arestin32 l.jpg

  • Clinical efficacy:

    • Arestin with debridement demonstrated 27% greater pocket reduction in molars compared to debridement alone

      • Mean reduction of 2 mm (pockets 7 mm +)

    • Effective in furcations