Adjunctive Therapies, antimicrobial chemotherapy, host modulation Flashcards
What is a general concept about the use of antibiotics and mechanical debridement in terms of plaque biofilm removal?
- you would need an antibiotic strength 500 times greater than the systemic therapeutic dose to effectively target bacteria in plaque biofilms
- therefore you need to physically disrupt the biofilm first so that the antibiotic can get access to the pathogens and inhibit biofilm formation
- antimicrobial agents are never used in the absence of mechanical debridement
What are a few examples (7) of indications for adjunctive antimicrobial therapies during phase 1 (non surgical) treatment?
- localized aggressive periodontitis
- generalized aggressive periodontitis
- necrotizing gingivitis and periodontitis
- periodontitis associated with or aggravated by systemic disease (i.e. poorly controlled diabetes)
- periodontitis refractory to treatment
- periodontal abscess with fever, malaise, etc.
What oral antiseptic is the gold standard anti-plaque and anti-gingivities agent?
Chlorhexidine gluconate (CHX) (0.12-0.2%)
- no systemic toxicitiy, rare HSN
- active against most bacteria and fungi, some viruses as well
- no microbial resistance reported
- side effects: taste and tooth discoloration
- i.e. extrinsic brown discoloration of teeth rinsing 2x a day for 3 weeks. removable with prophy paste.
What is the mechanism of action of Chlorhexidine?
- cationic, binds to negatively charged bacteria cell membranes
- at lower concentrations, membrane binding leads to increased permeability and leakage.
- at higher concentrations, membrane leakage leads to cytoplasmic entry and precipitation of cytoplasmic content, microbial cell death
- cationic nature contributes to high substantivity once it binds to salivary pellicle: slow release from tooth surfaces over 12 hours
Give 4 reasons why we prescribe CHX rinse
- adjunct to regular oral hygiene methods during phase 1 therapy (SRP) in high risk individuals (systemically compromised, refractory cases)
- mentally or phyiscally handicapped patients with low manual dexterity
- jaw fixation
- 1st wekk post oral surgery
When do we use local antimicrobial drug delivery? (3) i.e. subgingical delivery of 10% doxycycline (atridox) gel
- always as adjunct to SRP, never stand alone therapy
- residual isolated pockets greater than or equal to 5 mm, not responding well to initial SRP, especially if BOP present at reevaluation
- periimplantitis not responsive to SRP
What is the clinical benefit of local antimicrobial delivery as adjunct to SRP?
- in tx of periimplantitis, probing depth reductions may be > 1mm
- insignificant in mean probing depths
- most studies have shown reduction in “red complex” bacteria and shift to “healthier” bugs - questionable sustainability
Tetracycline
- bacteriostatic or bactericidal?
- actions
- highly effective against
- side effect
bacteriostatic
highly effective against A. actinomycetemcomitans
antimicrobial, anti-colagenolytic effects (inhibits CT destruction and promotes repair)
photosensitivity - severe skin burns
Alternative to Pencillin?
Clindamycin
Penicillin (Amoxicillin and Augmentin)
- spectrum / bacteriostatic or cidal?
- used in combo with?
- alternatives if allergic
- broad spectrum bactericidal
- used in combination with metronidazole
- if allergic: ciprofloxacin or clindamycin
most powerful antibiotic therapy for targeting both anaerobes and facultative bacteria
metronidazole with amoxicillin or cipro
What is periostat?
mechanism of action?
- sub-antimicrobial dose doxycycline (20 mg), bid for up to 9 months
- interferes with osteoclasts
currently the only FDA approved host modifier as adjunct to SRP, but can’t use as stand alone therapy
-potential benefit in high risk populations: aggressive diseases, refractory diseases, smokers
this antibiotic has been documented to produce favorable clinical and microbiological results in aggressive forms of periodontitis
tetracycline
