Discussion
inflammation
INFLAMMATION, PGA, EMD
Statistically significant changes in PPD were observed in both EMD + and EMD- groups from baseline to 6 months. However, the present study results suggest that the adjunctive, flapless use of EMD in the treatment of residual pockets does not additionally improve PPD reduction obtained with subgingival instrumentation alone. Furthermore, BoP was significantly reduced in EMD + (from 64.4% to 28.9%, With regard to CAL gain, the EMD + group (1.13 ± 1.58 mm) was significantly better compared to subgingival instrumentation alone (0.47 ± 1.06 mm), which was not observed in the abovementioned studies. This might be due to a different clinical scenario, as patients in the present trial had already undergone steps 1 and 2 of periodontal therapy (supra- and subgingival biofilm removal) recently, thus reflecting a later stage of periodontal treatment. On the other hand, a study by Jasa et al. included patients with a history of regular periodontal maintenance, again representing a different patient collective. The present study results suggest potential benefits of flapless EMD application on CAL gain rather than PPD reduction when applied for the treatment of remaining diseased sites at re-evaluation after initial periodontal therapy. This indicates that the effects of EMD seem to be more related to maintaining the levels of the gingival margin which could be due to the reduced level of inflammation and therefore less soft tissue shrinkage during the healing process.Interestingly, API was higher in EMD + compared to EMD- patients at the 6 months follow-up (44.1 ± 16.9% vs. 31.7 ± 4.8%, respectively; According to our results, no essential reduction of bacterial count in residual pockets was observed following subgingival instrumentation combined with flapless EMD application compared to subgingival instrumentation alone. This is in contrast to Wyganowska-Świątkowska who found that the use of EMD as an adjunct to subgingival instrumentation during initial periodontal therapy inhibited the growth of Gram-negative bacteria including The present findings also indicate no substantial influence of non-surgical EMD application on inflammatory markers in GCF. These results confirm findings by Giannopoulou et al. who assessed IL-1 expression at protein level in GCF 2 months after nonsurgical periodontal treatment with and without adjunctive EMD application [The present clinical investigation had some limitations. The limited sample size might have prevented further findings on clinical parameters, as well as on cytokine or bacterial levels. Focus on retreatment of periodontal sites that have already undergone initial periodontal therapy without sufficient site-specific success might have resulted in less improvement of clinical parameters when compared to first phase interventions. The inclusion of groups with application of PGA and/or 24% EDTA solution only might also provide further information, as PGA has also antimicrobial properties. Moreover, measurements of the assessed inflammatory and bacterial parameters at different time points might also elucidate effects of EMD application. Further research is needed to determine whether clinical benefit of nonsurgical EMD application might be influenced by site-specific conditions or treatment settings. Also, direct comparison of treatment outcome of surgical and nonsurgical application of EMD should be encouraged.