L2 Antimicrobials in periodontology Flashcards
Which microorganisms are associated with periodontal disease?
All gram negative bacteria, mostly anaerobic
- P. gingivalis
- Aggregatibacter actinomycetemcomitans (Facultative)
- Tannerella forsythensis
- Spirochetes of acute NUG
- Prevotella intermedia
- F nucleatum
- T denticola
What would antibiotics in periodontology need to target?
Would need abx effective against gram negative, anaerobic microorganisms and spirochetes.
Name the 4 types of antibiotic used in perio.
- Penicillin
- Nitroimidazoles
- Macrolides
- Tetracyclines
Describe the action of penicillins.
- Used for acute infections from gram +ve and -ve bacteria
- Not effective against aggregatibacter actinomyces
- Inhibit bacterial cell wall synthesis
- Most popular choice is amoxicillin
Describe the action of nitroimidazoles.
- E.g. Metronidazole
- Act by inhibiting DNA synthesis
- Broad spectrum, act against anaerobic cocci, gram +ve and -ve bacilli
- Very effective against anaerobes
- High concentration in GCF (up to twice of serum)
Metronidazole interacts with what drugs?
- Strong interaction with alcohol (pt needs to wait 48 hours after finishing abx to drink)
- Strong interaction with Warfarin, potentiates effects of Warfarin making pt at high risk of severe bleed
Describe the action of macrolides.
- E.g. Azithromycin
- Acts by disrupting protein synthesis
- Conventionally used to treat respiratory tract infections
- Alternative for pts allergic to penicillin
- Some benefits in grade C periodontitis and deeper sites
Name 3 tetracyclines.
- Tetracycline
- Minocycline
- Doxycycline
Describe the action of tetracyclines.
- Inhibit protein synthesis
- Effective against gram positive, spirochetes, anaerobic and falcutative bacteria
- High concentration in GCF
- Most commonly prescribed antibiotic in perio
When should tetracyclines be avoided?
- Children under 12, pregnant women, breastfeeding women (significant tooth staining)
- Patients with kidney disease (can exacerbate renal failure)
What substances decrease the absorption of tetracycline?
- Milk
- Antacids
- Calcium
Compare doxycycline vs tetracycline.
- Similair efficacy and spectrum
- Doxycycline concentration in GCF is higher than tetracycline
- Absorption is less sensitive to presence of food
At what stage of treatment are antimicrobials considered?
- Step 2 therapy
- For a compliant and engaged patient, good OH, low bleeding
Name some local delivery methods for antimicrobials.
- Mouth rinses and toothpastes (hypothetical)
- Subgingival irrigation
- Local delivery of abx
How many times does GCF turn around per hour?
GCF turns around 40 times per hour.
What are the 3 principles Goodson suggested for local delivery of antimicrobials in periodontal treatment?
Goodson principles 1996:
- The drug needs to be efficient in the periodontal pocket
- The drug concentration needed to be high enough
- Duration of the drug needed to be sufficient
What are the advantages of local delivery of antimicrobials?
- Applied directly to target area
- Higher concentrations achieved directly in the perio pocket
- Not reliant on pt compliance
- Reduced systemic side effects
- Reduced risk of resistance
What are the disadvantages of local delivery of antimicrobials?
- Expensive
- Delivery to the base of the pocket is questionable
- May result in failure of pocket closure
- Not active on the mature biofilm (antimicrobials require a clean surface to be effective)
Which 2 antimicrobials are used locally and how?
- Minocycline HCl 1mg (preloaded syringes: Dentomycin or Arestin)
- Chlorhexidine (gelatine discs, PerioChip)
Explain how Minocycline HCl 1mg is used and the treatment outcomes.
- Preloaded syringes (Dentomycin or Arestin)
- Applied every 2 weeks (3 times in total)
- Broad spectrum antibiotic which suppresses rods and spirochetes
- Reduces P.gingivalis and Aa
- 0.4mm clinical gains have been reported
Explain how chlorhexidine is used and the treatment outcomes.
- Hydrolysable gelatine disc placed into perio pocket of 5mm or more
- PerioChip contains 2.5mg chlorhexidine
- Requires 3 applications over 6 months
- Pt must avoid ID cleaning for 10 days after placement
- Maintains GCF concentrations for 7 days
- £20 per chip
What does current evidence suggest regarding the efficacy of local antimicrobials?
- EFP S3 guidance states that locally delivered antibiotics or Chx as an adjunct to subgingival instrumentation in periodontitis pts may be considered
- Grade 0 recommendation
- FGDP does not recommend locally delivered antimicrobials due to low quality evidence
When are local antimicrobials indicated?
- In isolated pockets which have not responded to conventional non-surgical treatment on several occassions
+ - Where there is no detectable calculus at the site and where the pt is maintaining good levels of plaque control
What are the advantages and disadvantages of systemic antimicrobial delivery?
Advantages:
- Cheaper
- Better evidence
Disadvanatges:
- Systemic side effects
- Increased resistance
- Requires good pt compliance
- Ineffective against mature biofilm
- Concentrations in GCF potentially lower than for local delivery
What does current evidence suggest regarding the efficacy of systemic antimicrobials?
- Clinical evidence: abx were found to improve clinical attachment level by 0.4mm, reduce bleeding on probing, increase pocket closure and reduce frequency of residual pockets
EFP S3:
- Not recommended for routine use
- May be considered as an adjunctive therapy in specific cases e.g. generalised stage 3 perio in young pt, severe/progressive perio, uncontrolled diabetes (Grade 0 recommendation)
What does EFP S3 level 0 guidance mean?
Evidence grade 0 = it is a clinical decision to be made based on each individual case
What is Periostat?
- Doxycycline Hyclate 20mg tablet (abx)
- Sub-antimicrobial dose (SDD)
- Inhibits action of MMPs (collagenases) to prevent periodontal tissue damage
- Some evidence to suggest benefits in reducing PPD and CAL
- POOR evidence, NOT RECOMMENDED by the S3 guidance! May lead to elevations in liver enzymes, concerns over resistance.
What is PerioWave?
- An antimicrobial photodynamic therapy
- Photoactivable solution placed in perio pocket, solution activated by light at specific wavelength
- Light activation produces cytotoxic free radicals
- Some evidence to show pocket depth improvement and CA gain short term
- POOR evidence, NOT RECOMMENDED by the S3 guidance
What is the general S3 guidance consensus regarding lasers in periodontics?
- NOT RECOMMENDED
- Some lasers can remove sub-gingival calculus and exert antimicrobial effects, but the side effects and cost effectiveness are not known. further research required
What does the EFP recommend overall regarding adjunctive antibiotics?
- Adjunctive antibiotics are justified in a small number of patients
- Those with many uncontrolled risk factors (e.g. diabetes) and those who are not responding favourably to other treatment approaches in spite of good compliance
- The treatment of such patients should be limited to dentists with adequate training in periodontology
What does the FGDP recommend overall regarding antimicrobial use in perio?
- Gingivitis: not recommended
- Necrotising diseases: recommended as an adjunct to local measures where there is evidence of systemic involvement
- Periodontitis: recommended as an adjunct to OHI, debridement and management of modifiable risk factors in patients aged under 40 with perio stage III or IV and Grade C
For patients with necrotising disease and evidence of systemic involvement, what antimicrobial drugs are recommended?
For patients with stage III/IV grade C periodontitis aged less than 40, what antimicrobial drugs are recommended?
- Complete full mouth RSD in the shortest time possible (7-10 days)
- At the last visit combine Amoxicillin 500mg and Metronidazole 400mg TDS for 5 days (“Perio Pill”)
- If allergic to pencillin, prescribe Azithromycin (500mg OD for 3 days) or Doxycycline (100mg BD for first day and then OD for up to 5 days)
When are antimicrobials recommended for a periodontal abscess?
- Adjunct to defintive treatment (e.g. drainage, extraction etc.) if there is evidence of systemic spread, pyrexia, lymphadenopathy
- Amoxicillin or Metronidazole
Are antimicrobials recommended for peri-implanitis?
Antimicrobials are not recommended as an adjunct to local management of peri-implantitis.
Summarise the antibitotics of choice for each periodontal condition.
