Systemic And Local Antimicrobials In Periodontal Therapy Question And Answers

Systemic And Local Antimicrobials In Periodontal Therapy

• Periodontal diseases in most cases can be successfully treated by mechanical therapy such as scaling and root planning, oral hygiene instructions to the patients, followed by regular maintenance visits.
• This standard treatment approach may be inadequate in certain forms of periodontal diseases (especially in aggressive forms of periodontitis) due to the following factors:
• Putative periodontal pathogens such as A. actinomycetemcomitans and P. gingivalis may invade the host tissues and recolonize the subgingival area after mechanical debridement.
• Periodontal pathogens may reside in areas such as narrow functions and root concavities that are inaccessible to periodontal instruments.

Read And Learn More: Periodontology Important Question And Answers

Question 1. Discuss the rationale of antimicrobial periodontal therapy.
Answer:

In periodontal therapy systemic antibiotics are used in the following situations:

• In the treatment of aggressive forms of periodontitis where mechanical therapy alone is insufficient.
• In acute periodontal conditions such as periodontal abscess and acute necrotizing ulcerative gingivitis.
• As a premedication in order to prevent systemic complications following mechanical periodontal therapy in patients with medical problems (such as rheumatic heart disease, etc).
• Provides adjunctive benefits to scaling and root planning in the treatment of chronic periodontitis
• Sometimes it may be necessary to use more than one antibiotic since a single antibiotic may not be effective against all putative periodontal pathogens.
• When two antibiotics are antagonistic to one another they have to be used one after another and this is known as serial therapy (example: doxycycline followed by metronidazole).
• Concurrent use of two antibiotics is known as combination therapy (for example amoxicillin and metronidazole).

Question 2. Name some of the systemic antibiotics used in the treatment of periodontal diseases.
Answer:

1. Tetracycline and its semisynthetic members doxycycline and minocycline.
2. Amoxicillin
3. Metronidazole
4. Clindamycin
5. Fluoroquinolones such as ciproflxacin and oflxacin.

Question 3. Describe the role of tetracycline and its derivatives in periodontal therapy.
Answer:

• Tetracyclines are bacteriostatic drugs. They have a broad spectrum of activity and act by inhibiting the protein synthesis of many gram-positive and gram-negative bacteria.
• Absorption after oral administration is about 60 to 70% for tetracycline hydrochloride and 95 to 100% for doxycycline and minocycline. After absorption, they are widely distributed in tissues and body fluids.
• Their concentration is about 2 to 10 times in GCF than that of serum. Minocycline reaches a very high concentration in saliva.
• Adverse effects include gastrointestinal disturbances, discoloration, and enamel hypoplasia of fetal teeth when given to pregnant women, impairment of hepatic function, and vestibular reactions such as dizziness and vertigo.
• Tetracycline had been the drug of choice in the treatment of periodontal diseases including the aggressive forms.
• Animal studies have shown that systemic administration of tetracycline reduces gingival inflammation and bone loss.
• Tetracyclines are effective against A. actinomycetemcomitans which invades the host tissues and hence are found to be beneficial in the treatment of localized aggressive periodontitis.
• They are also used in the treatment of chronic periodontitis as an adjunct to scaling and root planning. Long-term use of tetracyclines often results in the emergence of resistant strains.
• Many periodontopathogens have become resistant due to the indiscriminate use of tetracyclines.
• However, tetracyclines also exert an anti-collagenase effect which is an added advantage.
• Doxycycline has the advantage of patient compliance because of once-daily dosage. In serial therapy of chronic periodontitis, it is useful when prescribed first followed by metronidazole.
• One study has shown doxycycline to be effective in the treatment of refractory periodontitis when administered for 3 weeks thus reducing the risk of subsequent periodontal breakdown.
• Minocycline is found to be more effective against spirochetes and motile rods and reduces the bacterial count for 2 to 3 months.

Periodontal Therapy Dosage

• Tetracycline hydrochloride: 250 mg four times daily for 7 to 21 days. It should not be taken along with milk or antacids.
• Minocycline: 100 mg twice daily for 7 days.
• Doxycycline: 100 mg twice on the first day followed by 100 mg once daily for 6 days. Milk and antacids do not affect the absorption of doxycycline.

Question 4. Penicillins or amoxicillin in periodontal therapy.
Answer:

• Amoxicillin are extended-spectrum penicillin with improved activity against gram-negative organisms. They are relatively stable to gastric acid and hence absorbed well when given orally.
• Amoxicillin is bactericidal and acts by interfering with cell wall synthesis.
• Bacteria develop resistance by producing the enzyme beta-lactamase. More than 100 different beta-lactamases had been identified.
• Many strains of A. actinomycetemcomitans and P. gingivalis are susceptible to amoxicillin. To overcome the problem of bacterial resistance amoxicillin is combined with clavulanic acid.
• This combination has more effective bactericidal action as the beta-lactamase is inhibited by clavulanic acid.
• Amoxicillin plus clavulanic acid when administered as an adjunct to subgingival debridement and modified Widman flap surgery resulted in significant reduction in probing depths and gains in clinical attachment levels when compared to placebo therapy.

Penicillins Or Amoxicillin Dosage

• Amoxicillin: 500 mg three times daily for one to two weeks in the treatment of chronic and aggressive forms of periodontitis.
• Amoxicillin plus clavulanic acid: 375 mg (250 mg of amoxicillin + 125 mg of potassium clavulanate) three times daily for one to two weeks in the treatment of aggressive forms of periodontitis.

Question 5. Metronidazole in periodontal therapy.
Answer:

• Metronidazole is a nitroimidazole derivative which is bactericidal to anaerobic organisms. It acts by disrupting bacterial DNA synthesis.
• Common side effects when taken orally are gastrointestinal intolerance, antabuse-like effects, and an unpleasant metallic taste. It has been traditionally used in the treatment of gingivitis, acute necrotizing ulcerative gingivitis, and periodontitis.
• It has also been used in conjunction with root planning and surgery and also in combination with other antibiotics like amoxicillin. It is found to be effective against Porphyromonas gingivalis and Prevotella intermedia.
• However, it is has limited effect against A. actinomycetem comitans when used alone. In patients with recurrent periodontitis significant improvement in clinical parameters was observed after metronidazole was administered in combination with mechanical debridement.
• The presence of metronidazole in GCF is an added advantage.
• Localized aggressive periodontitis can be successfully treated by using a combination therapy of metronidazole and amoxicillin. The adjunctive use of this combination should be the choice of therapy for treating A. actinomycetemcomitans-associated periodontitis.

Metronidazole Dosage; 250 mg three to four times daily for 7 to 14 days for the treatment of ANUG and most forms of periodontitis.

Question 6. Write a note on clindamycin, fluoroquinolones, and macrolides.
Answer:

Clindamycin: Clindamycin is chlorine- a substituted derivative of lincomycin. It is effective against gram-positive and gram-negative anaerobic organisms.

• Like erythromycin, this drug also acts by inhibiting protein synthesis. It is useful in the treatment of chronic periodontitis.
• P. gingivalis is particularly susceptible to clindamycin therapy, being suppressed up to a period of 6 months after therapy.
• Systemic administration of clindamycin along with scaling brings about significant improvement in patients with active periodontal disease.
• One of the possible serious side effects of clindamycin therapy is the development of pseudomembranous colitis caused by superinfection by Clostridium defile.

Clindamycin Dosage: 150 to 300 mg for 7 to 14 days.

Fluoroquinolones

• Fluoroquinolones are active against a variety of gram-positive and gram-negative organisms.
• These are synthetically produced drugs and therefore not true antibiotics. They are bactericidal and act by blocking bacterial DNA synthesis.
• Ciprofloxacin and ofloxacin inhibit gram-negative cocci and bacilli including Pseudomonas, Neisseria, Haemophilus, and Campylobacter. Fluoroquinolones have excellent oral bioavailability.
• Serum concentrations of orally administered drugs are similar to those achieved by intravenous administration.
• Most common side effects are nausea vomiting and diarrhea. Ciprofloxacin and ofloxacin should not be used for patients below 18 years and during pregnancy.
• Ciprofloxacin is effective against all strains of A. actinomycetemcomitans and it is used alone or in combination with metronidazole.

Flouroquinolones Dosage

• Ciprofloxacin: 500 mg twice daily for 5 days
• Ofloxacin: 400 mg twice daily for 5 days.

Macrolides

• Macrolide contain a many-membered lactone ring to which is attached one or more deoxy sugars.
• They inhibit protein synthesis by binding to the 50S ribosomal subunits of sensitive micro-organisms.
• They can be bacteriostatic or bactericidal depending on the concentration of the drug and type of bacteria.
• Azithromycin is an azalide class of macrolide. It is effective against anaerobes and gram-negative bacilli. High concentration is achieved in tissues, macrophages, and polymorphs.
• The drug is highly effective against all serotypes of Aggregatibacter actinomycetemcomitans, and against
• Porphyromonas gingivalis. It is a relatively nontoxic drug.

Macrolides Dosage

Azithromycin: 500 mg once daily for 3 days; 250 mg once a day for 5 days after an initial loading dose of 500 mg.

Question 7. Local drug delivery in periodontal therapy.
Answer:

• The drawback of using systemic antibiotics in the treatment of periodontal disease was that an adequate concentration at the site of action was not achieved and the active product was not retained locally for a sufficient period of time.
• Since, periodontal disease is the result of a local bacterial infection with a pathogenic microflora within the periodontal pocket, targeting the site of infection with an anti-infective agent with effective concentration and for sufficient time, could help treat periodontal disease and markedly reducing the side effects of systemic antibiotic therapy.
• These drugs are applied subgingivally at the site of infection following scaling and root planning

Some of the commercially available locally delivered antibiotics include

1. Actisite: Ethylene/vinyl acetate copolymer fier containing tetracycline, releases 1300 microg/ mL of the drug into the periodontal pocket for a period of 10 days
2. Atridox: It is gel system containing 10% doxycycline in a syringe
3. Arestin: Contains 2% minocycline is encapsulated in bioresorbable microspheres in a gel carrier
4. Elyzol: Contains metronidazole benzoate in a 5% dental gel.

• A commercially available local delivery device to deliver antiseptic agents subgingivally is called Periochip. It contains 2.5 mg of chlorhexidine gluconate in a biodegradable chip.
• These agents have been shown to be effective in reducing probing depth, bleeding on probing, and periodontal pathogens and provide a gain in clinical attachment levels.

Conclusion

• The rationale of use of antibiotic therapy is based on the premise that periodontal disease is bacterial in origin.
• Its use in chronic periodontitis as mono-therapy is not validated by clinical evidence, whereas it may be of benefit in aggressive and refractory forms of periodontal disease.
• In the era of emerging bacterial resistance, the use of antibiotics must be restricted and need-based.