Role of Doxycycline on the Finding of Fusobacterium Nucleatum in Periodontitis

Background & Aim: To evaluate the efficiency of systemically
applied Doxycycline in a daily dose of 1 × 100 mg. and 2 × 20 mg. on Fusobacterium nucleatum (Fn) in patients with periodontitis.
Methods: The examined group consisted of 60 patients with a
moderate form of chronic periodontitis where the periodontal
depth was 3–5 mm, aged 30–70 years old. The first group con
sisted of 30 patients who were treated with Doxycycline 2 × 20 mg. daily (morning and evening) for 75 days and a second group with the same number of subjects who received 1 × 100 mg. daily (morning), 30 days. The total dose received by each subject during the research was 3 g.
Gingival fluid samples from which Fn was determined were
collected using 2 × 5 mm. methylcellulose strips (Whatmann
3 MM Chromatography paper). Paper absorbents with the sam
ple are treated on nutrient media by rolling on the media (Maki's method). The material is incubated at 36°C ± 1°C in anaerobic conditions (Anaerocult A mini—MERCK). The final identification of the bacteria was done with an automatic system for the identification of bacterial species- VITEK 2 COMPAQ.
Results: In the first group of patients who received doxycycline 2 × 20 mg. daily for 2.5 months, after 2.5 months 13 (21.67%) positive and 17 (28.33%) negative findings of Fn were registered. In the second group of patients who received doxycycline 100 mg. daily for 30 days, 21 (35.00%) positive and 9 (15.00%) negative findings of Fn were registered. In the distribution shown for Pearson chi- square = 4.34 and p < 0.05 (p = 0.04) there is a significant difference in the findings of Fusobacterium nucleatum
(Fn) between the two groups of patients.
Conclusions: The daily dose of 2 × 20 mg. doxycycline in patients with periodontitis more effectively reduces the anaerobe Fusobacterium nucleatum (Fn).