Bài 12

In a periodontal pocket, the bacteria form a highly structured and complex biofilm. As this process continues, the bacterial biofilm extends so far sub-gingivally that the patient:

• Cannot reach it during oral hygiene efforts.

• Can reach it during oral hygiene efforts.

• Can reach it to clean roots.

• Can reach it to control biofilm.

Complex biofilm may now offer some protection from:

• The host’s immunologic mechanisms in the periodontal pocket.

• Antibiotics used for treatment.

• Medicine placed in the gingival pockets.

• Saliva.

An antibiotic strength needs to be effective against bacteria that have become arranged in biofilms is:

• 100 times greater than the usual therapeutic dose.

• 300 times greater than the usual therapeutic dose.

• 500 times greater than the usual therapeutic dose.

• 1000 times greater than the usual therapeutic dose.

Systemic anti-infective therapy (oral antibiotics) and local anti-infective therapy (placing anti-infective agents directly into the periodontal pocket):

• Can reduce the bacterial challenge to the periodontium.

• Cannot reduce the bacterial challenge to the periodontium.

• Cannot reduce the bacterial challenge in gingival sulcus.

• Cannot reduce the bacterial challenge in periodontal pocket.

An anti-infective agent is a chemotherapeutic agent that acts by:

• Removing biofilm.

• Removing calculus

• Cleaning tooth surfaces.

• Reducing the number of bacteria present.

To destroy microorganisms and to inhibit their reproduction or metabolism, an antiseptic is chemical antimicrobial agent that can not be applied:

• Topically to mucous membranes.

• Topically to wounds.

• Subgingivally.

• Saliva or mouthwash

Anti-infective agents can be administered locally or orally. When administered orally, many of these agents can be found in gingival crevicular fluid (GCF). With either approach, their purpose is to:

• Prevent dental caries.

• Reduce the number of bacteria present in the diseased periodontal pocket.

• Reduce calculus and dental plaque in subgingiva.

• Reduce the number of white blood cells in gingival crevicular fluid.

The local administration of anti-infective agents, generally directly to the pocket, has the potential to provide:

• Greater concentrations directly to the infected area.

• Greater concentrations directly to the pulp.

• Greater concentrations directly to the attached gingiva.

• Greater concentrations directly to the periodontal ligament.

Tetracyclines (especially doxycycline) are chemotherapeutic agents that can not:

• Reduce collagen destruction.

• Reduce bone destruction.

• Reduce periodontal pathogens in periodontal tissues.

• Increases the healing ability of gingival pockets.

Although oral bacteria are susceptible to many antibiotics, no single antibiotic at the concentrations achieved in body fluids inhibits all putative periodontal pathogens. A combination of antibiotics may be necessary to eliminate:

• All putative pathogens from dental caries.

• All dental plaque.

• Biofilm.

• All putative pathogens from some periodontal pockets.