Effect of the enamel matrix derivative Emdogain (R) on the growth of periodontal pathogens in vitro

Objectives: The aim of this study was to evaluate the effect of Emdogain(R) (EMD), used for periodontal regeneration, on the growth of periodontal pathogens like Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia. For comparison, we studied the effect of EMD on several microbes associated with other oral diseases as well as its effect on non-pathogenic oral inhabitants. Methods: Freshly prepared EMD or its vehicle propylene glycol alginate (PGA) alone were added to calibrated suspensions of microbes. As a control, imitating the post-surgical subgingival situation after flap closure, a serum/NaCl-solution mixture was used. Aliquots for growth assays were taken at scheduled times for calculation of colony-forming units and cell densities over an observation period of 24 h. Additionally, EMD was spotted onto selected, newly seeded microbes growing on agar plates to see if growth inhibition zones could be produced. Results: The study revealed a marked inhibitory effect of EMD on the growth of the gram-negative periodontal pathogens. A. actinomycetemcomitans showed a significant decrease (p=0.012) in viable counts after 24 h when EMD was added at baseline. P. gingivalis and P. intermedia also showed a marked growth reduction in the presence of EMD and in these cultures no viable microbes could be detected anymore after 24 h. In contrast, no significant growth inhibition was observed in gram-positive bacteria. Conclusions: The results suggest that EMD has a positive effect on the composition of bacterial species in the post-surgical periodontal wound, by selectively restricting growth of periopathogens that could hamper the wound healing and reduce the outcome of regenerative procedures.