# New Local Drug Delivery with Antibiotic in the Nonsurgical Treatment of Periodontitis--Pilot Study
## 5 Discussion
After application of SRP alone, a decrease in the number of _Fusobacterium nucleatum_ and _Micromonas micros_ was observed. In the studies conducted by [PERSON] et al. [10], reduction in pathogens (including _Porphyromonas gingivalis, Tanzania forsythia_, or _Aggregatibacter actinomycetemcomitans_) after local application of piperacillin with taxobactam, in comparison with application of only mechanical cleaning, was obtained in both groups after 26 weeks. On the other hand, significant reduction of _Fusobacterium nucleatum_, _P. micra_, and _T. danticola_ was obtained in the group in which the treatment was combined with local antibiotic therapy. Due to bacteria organization within the biofilm present in the periodontal pockets and the presence of periopathogenic bacteria in the tissues of the host, eradication of periopathogens and long-term improvement of clinical and in particular, microbiological parameters, is virtually impossible. In the case of local application of doxycycline, the results of clinical and microbiological tests are inconclusive. Reports on considerable improvement of clinical parameters and reduction in periopathogens after SPR combined with intrapocket administration of antibiotic [16; 17] are available. Long-term observations, however, do not indicate considerable benefits [18]. At the same time, some scientists do not prove significant differences in results with regard to the independent use of SRP in periodontal disease treatment [19]. Difficulties in obtaining complete reduction of periopathogens, regardless of the type of therapy, were also presented in the studies by [PERSON] et al. [20] after local application of tetracycline fibers [21]. The study included seventeen patients, with whom microbiological analysis of subgingival samples collected mesially-distally from 852 areas at the beginning and after a month of using the preparation was conducted. In the basic study, 46 samples, from 10 positive individuals, showed positive results for _P. gingivalis_; 82 samples, from 5 individuals, were also identified as positive in terms of _A. actinomycetemcomitans_. The presence of _A. actinomycetemcomitans_ and _P. gingivalis_ was not confirmed in the material collected from 3 patients. Microbiological tests conducted one month after periodontal treatment showed that 89% of areas which initially showed positive results in terms of pathogens were negative, while 16 areas which were initially identified as negative showed positive results. With regard to _A. actinomycetemcomitans_, 77% of areas which were identified as positive in terms of bacteria presence in the first test were later identified as negative, but 5 areas which were initially identified as negative showed positive results. During the examinations of patients whose results of the microbiological test remained positive, another attempt at applying local treatment using tetracycline fibers was made. Despite another attempt at treatment, microbiological tests still showed the presence of _P. gingivalis_ in 5 individuals; and in 4 patients, the results for _A. actinomycetemcomitans_ remained positive. Those 9 patients were finally subjected to systemic antibiotic treatment (\(3\times 250\) mg metronidazoleazole and \(3\times 375\) mg amoxicillin/per day for 7 days). Despite all the efforts, after 3 months _P. gingivalis_ was again detected in 3 individuals and _A. actinomycetemcomitans_ was isolated from 1 area. Organization of periopathogens within the biofilm, their diversity, and ability to quickly recolonize bacteria still constitutes a great therapeutic challenge. Nonsurgical methods (SRP) are still the basis for treatment of periodontium diseases, and local or general application of antibiotic therapy is still ineffective in terms of periopathogen elimination [22].