⭐ CHEMOTHERAPEUTIC AGENTS
📌 POINTS TO PONDER
🔹Pin Cushion Effect- One charged end of chlorhexidine (CHX) molecule binding to the tooth surface and the other remaining available to interact with bacterial membrane as microorganism approaches the tooth surface as pin-cushion effect.
🔹Substantivity of CHX is around 12 hrs.
🔹Substantivity of Triclosan is around 5 hrs.
🔹Substantivity of Cetylpyridium is around 3-5 hrs.
🔹Chemotherapeutic agents used as premedication in periodontal surgery are anxiolytics, antibiotics,antiseptics and NSAIDs.
🔹Three groups of antimicrobials which interfere with food absorption are tetracyclines, quinolones and azithromycin.
🔹Chlorhexidine is free from systemic toxicity in oral use.
🔹Chlosite is a gel with 1.5% Chlorhexidine. It is a combination of chlorhexidine gluconate-slow release
(0.5%) and chlorhexidine dihydrochloric -rapid release (1.0%).
🔹Antiseptic is applied topically or subgingivally on living surfaces whereas disinfectant is applied to inanimate surfaces to destroy microorganisms.
📌 Commonly Used Chemotherapeutic Agents In Periodontics :
🔸Antibiotics
🔸Analgesics
🔸Sedatives
🔸Muscle relaxants
🔸Postoperative periodontal dressings
🔸Desensitizing agents
🔸Chemical antiplaque agents
🔸Dentifrices
🔸Anticalculus agents
🔸Corticosteroids
🔸Hemostatics and Vasoconstrictors
🔸Anesthetics
📌 Chemical Antiplaque Agent Categorized Into :
🔸Antiadhesive: It prevents bacterial attachment to the tooth, e.g. chlorhexidine (CHX), delmopinol, amine alcohol.
🔸Antimicrobial: It stops or slows bacterial proliferation, e.g. CHX, antibiotics.
🔸Established plaque removal or chemical toothbrush, e.g. amine alcohol, enzymes.
🔸Antipathogenic: It alters the pathogenicity of plaque.
📌 Local drug delivery system should meet the following criteria to be effective in treating disease:
🔸It inhibits or kills the putative pathogen.
🔸It should be able to reach the site.
🔸It should be in adequate concentration.
🔸It should be there long enough.
🔸It should not be toxic.
📌 VIVA VOCE
Q1. What is the advantage of chemical plaque control over mechanical plaque control?
Ans. The advantage of chemical approach is that zone of diffusion achieved with chemical agent is greater than the limited radius of effect of a mechanical therapy.
Q2. Which mouthwashes produce staining?
Ans. Chlorhexidine, stannous fluoride and cetylpyridinium chloride produce staining.
Q3. Classify mouthrinses.
Ans. Mouthrinses have been classified into following agents:
🔸Group A agents: They are described as antiplaque agents that inhibit plaque formation to such an extent that they prevent the development of gingivitis. This group includes CHX, acidified sodium chlorate, salifluor and delmopinol. Their efficacy is reflected in mouthwash form and they can be used instead of conventional mechanical plaque removal such as when the individual cannot effectively clean their teeth.
🔸Group B agents: They are described as plaque inhibitory which should be used as adjuncts to mechanical cleaning, such as toothbrushing. This group includes cetylpyridinium chloride, essential oil (listerine) and triclosan rinses.
🔸Group C agents: They are rinses with little or no effect on plaque accumulation and would be expected to have a largely cosmetic role, such as breath freshening. Rinses in this group include products containing sanguinarine, oxygenating agents and rinses containing hexetidine.
Q4. All strains of Actinobacillus are susceptible to which antibiotic?
Ans. Ciprofloxacin is susceptible to all strains of Actinobacillus.
Q5. What are the advantages of ciprofloxacin over other antibiotics for combating aggressive periodontitis?
Ans. The advantages of ciprofloxacin over other antibiotics for combating aggressive periodontitis are:
🔸It has minimal effect on Streptococcus species, which is associated with periodontal health.
🔸All strains of A. actinomycetemcomitans are susceptible to ciprofloxacin.
Q 6. What are anti-edematous drugs?
Ans. For the prevention of traumatic edema and the treatment of postoperative and traumatic edema, certain enzymes and antihistamines like Hyaluronidase, Streptokinase and Serratiopeptidase are used.
Q 7. What is Serratiopeptidase ?
Ans. This proteolytic enzyme hydrolyses inflammatory mediators responsible for edematous conditions including bradykinin, histamine and serotonin. It exerts potential anti-inflammatory, antiedemic and fibrinolytic activity with rapid impact on localized inflammation. For its activity, it binds to alpha -2-macroglobulin in the blood in the ratio of 1: 1. This helps to inhibit its antigenicity but retains its enzymatic activity and is slowly, transferred to the site of inflammation.
Dosage: 10–20 mg 6 hourly.
Q8. Which drugs concentrate in GCF? Write their concentration in GCF and serum.
Ans.
🔸Doxycycline: Dose 200 mg; Crevicular fluid concentration 2–8 μg/mL; Serum concentration 2–3 μg/mL.
🔸Tetracycline: Dose 500 mg; Crevicular fluid concentration 5-12 μg/mL; Serum concentration 3–4 μg/mL.
🔸Metronidazole: Dose 500 mg; Crevicular fluid concentration 8- 10 μg/mL; Serum concentration 6-12 μg/mL.
🔸Amoxicillin: Dose 500 mg; Crevicular fluid concentration 3-4 μg/mL; Serum concentration 8 μg/mL.
🔸Chlorhexidine (CHX): Periochip; Crevicular fluid concentration 100 μg/mL.
🔸Actisite: Crevicular fluid concentration 1300 μg/mL; Serum concentration 5–12 μg/mL.
🔸Clindamycin: Serum concentration 1-2 μg/mL.
Q9. What is substantivity?
Ans. The quality of prolonged contact time between a substance and substrate is known as substantivity.
Q10. What are the adverse effects of chlorhexidine?
Ans. Staining, taste alteration, oral mucosal erosion and increased calculus formation.
📌 MCQs
💡Periostat is:
A. 20 mg capsule of doxycycline hyclate
B. 40 mg capsule of doxycycline hyclate
C. 100 mg capsule of doxycycline hyclate
D. 200 mg capsule of doxycycline hyclate
Answer : A
💡The active ingredient in periochip is:
A. Tetracycline
B. Minocycline
C. Metronidazole
D. Chlorhexidine
Answer : D
💡The antibiotic to which all strains of Actinobacillus are susceptible is:
A. Tetracycline
B. Ciprofloxacin
C. Amoxicillin
D. Metronidazole
Answer : B
💡Which of the following antibiotics can concentrate at sites of periodontal inflammation:
A. Amoxycillin
B. Azithromycin
C. Metronidazole
D. Clindamycin
Answer : B
💡Metronidazole:
A. penetrates stagnation areas well
B. is mainly active against gram-positive aerobes
C. is effective in the management of necrotizing ulcerative gingivitis.
D. is mainly concentrated in saliva
Answer : C
💡If periodontal procedures have to be carried out more than once, the minimum gap between two prophylactic antibiotic regimes in case of prophylaxis against SABE, should be:
A. 2 days
B. 7 days
C. 20 days
D. 42 days
Answer : B
💡Which of the following chemotherapeutic agents has been shown to have a side effect of tooth staining ?
A. Sanguinarine
B. Chlorhexidine
C. Hydrogen Peroxide
D. Phenolic compound
E. Sodium benzoate
Answer : B