Local antibiotic therapy guided by microbiological diagnosis

Area of Science:

• Microbiology
• Periodontology
• Infectious Diseases

Background:

• Periodontitis is a common oral disease.
• Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans are key pathogens in periodontitis.
• Standard mechanical therapy may not eliminate these bacteria.

Purpose of the Study:

• To determine the distribution of P. gingivalis and A. actinomycetemcomitans in periodontitis patients post-therapy.
• To evaluate the efficacy of local antibiotic therapy for persistent bacteria.
• To assess the impact of additional systemic antibiotics.

Main Methods:

• 17 periodontitis patients were sampled for P. gingivalis and A. actinomycetemcomitans.
• Teeth with positive cultures received local tetracycline fiber therapy.
• Microbial sampling was repeated after local and systemic antibiotic treatments.

Main Results:

• Local tetracycline therapy reduced P. gingivalis in 89% and A. actinomycetemcomitans in 77% of sites.
• Recurrence and re-emergence of bacteria were observed after initial local therapy.
• Systemic antibiotics further reduced bacterial load, but complete eradication was not achieved.

Conclusions:

• Microbiologically guided local antibiotic therapy is effective but not curative for P. gingivalis and A. actinomycetemcomitans.
• Systemic antibiotics enhance bacterial reduction but do not guarantee eradication.
• Bacterial re-emergence suggests recolonization (A. actinomycetemcomitans) or failed eradication (P. gingivalis).