Periodontics › Treatment
Antimicrobials & Local Drug Delivery
High-yield revision notes with linked practice questions, written for dental students and candidates preparing for the ADC and other licensing examinations.
High-yield notes
Antibiotics are only an adjuncts to scaling and root planing.
Antibiotic of strength 500 times greater than the usual therapeutic dose may be needed to be effective against bacteria arranged in biofilms.
Metronidazole should not be administered along with warfarin, lithium & alcohol (disulfiram like reaction).
The most widely used antibiotics are penicillins. They inhibit bacterial cell wall production.
Clindamycin has shown efficacy in patients with periodontitis refractory to tetracycline therapy. It is used in patients allergic to penicillin. The most common side effect is pseudomembranous colitis
CMT stands for chemically modified tetracycline.
Scaling and root planing are mechanical modes of anti-infective therapy.
The amount of bone destruction by host's immunologic response against bacteria (indirect bone loss) is greater than that of the bone loss induced by the bacteria itself.
No single antibiotic at concentrations achieved in body fluids inhibits all putative periodontal pathogens.
Tetracyclines
- used in treating refractory periodontitis, including localized aggressive periodontitis (LAP)
- Tetracyclines have the ability to concentrate in the periodontal tissues (GCF: 2-10 times than blood) and inhibit the growth of Aggregatibacter actinomycetemcomitans.
- In addition, tetracyclines exert an anticollagenase effect that can inhibit tissue destruction and may aid bone regeneration.
- bacteriostatic and are effective against rapidly multiplying bacteria
- tooth discoloration occurs when administered to children up to age 12 years.
- Minocycline is the only tetracycline that can discolor permanently erupted teeth and gingival tissue when administered orally.
- the most photosensitizing agent in the tetracycline category is doxycycline
Practice questions
Select an option to check your answer. Answers are shown below each question.
Not true about doxycycline
- Arecommended dosage when used as an antiinfective agent is 100 mg bid the first day, then 100 mg once a day
- BTo reduce GI upset, 50 mg can be taken bid
- Csub-antimicrobial dose (to inhibit collagenase), doxycycline is recommended in a 20-mg dose twice daily
- Dall are true
Metronidazole alone is not effective against
- AA. actinomycetemcomitans
- BPorphyromonas gingivalis
- CPrevotella intermedia
- DTreatment of ANUG
The only antibiotic in periodontal therapy to which all strains of A. actinomycetemcomitans are susceptible is
- AClavulanic acid
- BCephalosporin
- CDoxycycline
- DCiprofloxacin
Drugs that should not be combined to produce desired effect
- AAmoxicillin-clavulinic acid
- BAmoxicillin-metronidazole
- CAmoxicillin-Tetracycline
- DMetronidazole-ciprofloxacin
The use of antibiotics to treat plaque induced gingival diseases is
- ADone after scaling and root planing
- BDone before scaling and root planing
- CDone before and after scaling and root planing
- DContraindicated
Local drug delivery is not preferred when
- Aprobing depths greater than 5 mm with inflammation still present after conventional therapy.
- Bmultiple sites present in the same quadrant
- Cbarrier membranes are placed
- Dpatient is medically compromised
2% minocycline as local delivery agent is available as
- AAtridox
- BPeriochip
- CArestin
- DPeriogard
These notes are compiled from standard periodontology texts for study purposes. They are a revision aid, not a substitute for your own reading or current clinical guidelines. If you spot an error, please leave a comment.