Systemic antimicrobials in periodontics Flashcards
What are the different stages?
1: Initial periodontitis
2: Moderate
3: Severe with potential for additional tooth loss
4: Severe with potential for loss of dentition
What is the extent and distribution?
Localised, generalised or MIP (molar incisor pattern)
What are the different grades?
A - slow rate
B- moderate rate
C - rapid rate
What are antibiotics?
Drugs that kill or halt the multiplication of bacterial cells at concentrations relatively harmless to host tissues, can be used to treat infections caused by bacteria.
what are the classifications of antibiotics?
Beta lactams - penicillin (beta lactamase inhibitors - co amoxiclav) Aminoglycosides - gentamycin Sulphonamides - sulfa group Tetracyclines - doxy, mino Azoles - metronidazole Quinolones - ciprofloxacin Macrolides - erythromycin, azithromycin
what are antibiotics classified by?
Narrow spectrum - acts on a few organisms
Broad - acts on a lot
What are antibiotics mode of action?
Inhibition of cell wall synthesis
Inhibition of cytoplasmic membrane function
Inhibition of nucleic acid synthesis
Inhibition of ribosomal function and protein synthesis
Inhibition of folate metabolism
How does amoxycillin work?
Beta lactams
Inhibits cell wall synthesis - bactericidal
How does metronidazole work?
Inhibits nucleic acid synthesis by breaking down DNA strands - bactericidal
How do tetracyclines and macrolides work?
Inhibit protein synthesis - bacteriostatic
Disadvantages of antibiotics
Hypersensitivity
Gastrointestinal disturbances
Alterations in commensal flora - oral candidosis
Drug interations - no alcohol with metronidazole
Avoid during pregnancy
Bacterial resistance
How are we reducing use of antibiotics?
Evidence based standards for prescribing
Ensure competency for prescribing
Auditing impact
Optimising outcomes for patients prescribed
What are factors affecting efficacy?
Binding of drug to tissue
Protection of key organisms by non target organisms binding
Bacterial tissue invasion
Previous drug therapy
Non pocket infected sites - dorsum of tongue
Choice of bacteriacidal/bacteriostatic
What can bacteria produce that stops beta lactam drugs (amoxycillin)
Beta lactamase - use clavulanic acid which inhibits this
What are reasons for failure?
Lack of culture and sensitivity Failure of drainage Non bacterial cause Incorrect drug duration or dose lack of compliance defective host response Smoking - interferes with healing Inability of drug to bind to tissue Resistance
When do we use culture and sensitivity (PCR, elisa…)
Only if clinically demanding
Indications
Not for chronic gingivitis and periodontitis
Maybe for aggressive - stage 3/4 in younger patients
Necrotising periodontal diseases
Perio endo lesions with systemic involvement
Sometimes periodontitis as a manifestation of systemic disease - diabetic patients
Pericoronitis with evidence of systemic spread
WHat to prescribe for aggressive periodontitis?
Penicillins
Tetracyclines
Macrolides
Metronidazole
How much to prescribe?
Check allergies
Prescribe on last day of RSD complete within a week
500mg amoxycillin
400mg metronidazole
Penicillin allergy 500mg azithromycin 3 days compliance may be better
What is necrotising ulcerative gingivitis?
Bacterial infection by spirochaetes, fusiform
Treatment: RSD, metronidazole
Chlorhexidine mouth rinse
What is chronic periodontitis>
Prevalent in adults
Slow to moderate progression
Plaque aetiology
Destruction consistent with local factors
Treat with initial, corrective, supportive
What is aggressive periodontitis?
Patient healthy no contributive medical history
Rapid attachment loss and bone destruction
Family history
Clinical presentation of AgP
MIP
CAL
Deep pockets
Gingival inflammation
Alveolar bone loss - angular defects incisors and vertical bone loss
Arc shaped bone loss distal of second molar to mesial of first
Amount of plaque not consistent with amount of periodontal destruction present
Features of AgP
Elevated proportions of aggregatibacter actinomyceomitans and p gingivalis
Phagocyte abnormalities
Hyper responsive macrophage phenotype elevated levels of prostaglandins
Interproximal attachment loss on at least two permanent teeth one a first molar and involving no more than two teeth other than first molars/incisors
What are necrotising periodontal diseases?
Necrotising gingivitis
Necrotising periodontitis
Necrotising stomatitis
