Systemic antimicrobials in periodontics

Question 1

What are the different stages?

Answer 1

1: Initial periodontitis
2: Moderate
3: Severe with potential for additional tooth loss
4: Severe with potential for loss of dentition

Question 2

What is the extent and distribution?

Answer 2

Localised, generalised or MIP (molar incisor pattern)

Question 3

What are the different grades?

Answer 3

A - slow rate
B- moderate rate
C - rapid rate

Question 4

What are antibiotics?

Answer 4

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.

Question 5

what are the classifications of antibiotics?

Answer 5

Beta lactams - penicillin (beta lactamase inhibitors - co amoxiclav)
Aminoglycosides - gentamycin
Sulphonamides - sulfa group
Tetracyclines - doxy, mino
Azoles - metronidazole
Quinolones - ciprofloxacin
Macrolides - erythromycin, azithromycin

Question 6

what are antibiotics classified by?

Answer 6

Narrow spectrum - acts on a few organisms

Broad - acts on a lot

Question 7

What are antibiotics mode of action?

Answer 7

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

Question 8

How does amoxycillin work?

Answer 8

Beta lactams

Inhibits cell wall synthesis - bactericidal

Question 9

How does metronidazole work?

Answer 9

Inhibits nucleic acid synthesis by breaking down DNA strands - bactericidal

Question 10

How do tetracyclines and macrolides work?

Answer 10

Inhibit protein synthesis - bacteriostatic

Question 11

Disadvantages of antibiotics

Answer 11

Hypersensitivity
Gastrointestinal disturbances
Alterations in commensal flora - oral candidosis
Drug interations - no alcohol with metronidazole
Avoid during pregnancy
Bacterial resistance

Question 12

How are we reducing use of antibiotics?

Answer 12

Evidence based standards for prescribing
Ensure competency for prescribing
Auditing impact
Optimising outcomes for patients prescribed

Question 13

What are factors affecting efficacy?

Answer 13

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

Question 14

What can bacteria produce that stops beta lactam drugs (amoxycillin)

Answer 14

Beta lactamase - use clavulanic acid which inhibits this

Question 15

What are reasons for failure?

Answer 15

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

Question 16

When do we use culture and sensitivity (PCR, elisa…)

Answer 16

Only if clinically demanding

Question 17

Indications

Answer 17

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

Question 18

WHat to prescribe for aggressive periodontitis?

Answer 18

Penicillins
Tetracyclines
Macrolides
Metronidazole

Question 19

How much to prescribe?

Answer 19

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

Question 20

What is necrotising ulcerative gingivitis?

Answer 20

Bacterial infection by spirochaetes, fusiform
Treatment: RSD, metronidazole
Chlorhexidine mouth rinse

Question 21

What is chronic periodontitis>

Answer 21

Prevalent in adults
Slow to moderate progression
Plaque aetiology
Destruction consistent with local factors
Treat with initial, corrective, supportive

Question 22

What is aggressive periodontitis?

Answer 22

Patient healthy no contributive medical history
Rapid attachment loss and bone destruction
Family history

Question 23

Clinical presentation of AgP

Answer 23

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

Question 24

Features of AgP

Answer 24

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

Question 25

What are necrotising periodontal diseases?

Answer 25

Necrotising gingivitis
Necrotising periodontitis
Necrotising stomatitis