## 4 Discussion
In our study, we have shown very the high antib biofilm activity of octenidine dihydro-drochloride released from lozenges. Although no MBEC values were obtained in this study's particular settings (presented in Figures 3-6), the average values of biofilm reduction [%] exceeded 80%. One should remember that typical rules of local administration of antiseptic-containing lozenges permit their ingestion a few times a day, and this recurring provision of an antimicrobial can control (or prevent) pathogenic biofilms from spreading [27]. The quantitative data presented in Figures 3-6 were obtained by qualitative microscopic observation (Figure 7), showing, among others, a very high share of dead cells in _A. actinomycetemcomitans_ biofilm after treatment with OA. Because this pathogenic bacterium is more and more frequently recognized as the etiological factor of aggressive jaw infections [28], the potential of OA application to eradicate _A. actinomycetemcomitans_ biofilm, indicated in this study, may find its translational value. Analogically, the high ratio of eradication of methicillin-resistant _Staphylococcus aureus_ (such as the strain applied in the present study) may indicate the potential of OCT to be applied against this multi-resistant and widespread Gram-positive coccus. The high antibiofilm efficacy of octenidine dihydrochloride antiseptic was indicated not only in the current in vitro work, but also by the large amount of other research performed both in laboratory and clinical conditions generally acknowledging its efficacy as an antiseptic. The relatively small size of the octenidine molecule may be one of the factors enabling its penetration into compact biofilm structure and exerting antimicrobial activity against biofilm-forming cells. When octenidine is administered to the oral cavity in a stable carrier, the control of its release is higher than it is in the case of a liquid formulation. Moreover, the time of exposure of the biofilm to octenidine is significantly higher if this antiseptic is released from a stable carrier rather than the aforementioned liquid formulation. We are aware of the specific limitations of the current study, being mostly a result of its initial in vitro character. The oral cavity and throat are colonized by a vast spectrum of interacting microorganisms. Moreover, the environment in this niche is of a complex, dynamic character due to (among others) saliva and tongue movements and because of the activity of the immune system and the application of hygienic procedures [29]. Thus, a study such as ours using in vitro models is undoubtedly a simplification of the processes occurring within the oral cavity and the throat, not only because of the limitations of any in vitro models but also because we focused on the major pathogenic species and not on their inter-species consortia. On the other hand, we applied various in vitro models and various assessment techniques to obtain insight on the activity of octenidine dihydrochloride released from lozenges against pathogenic biofilms. Taking this fact into consideration, it can be stated that a study such as ours represents an important step in the direction of clinical research in that matter. It may thus be concluded that such a formulation as the one investigated in the current work may find broad application (in both ambulatory and hospital patients or non-patient customers) in the maintenance of oral health hygiene and the eradication of biofilm-based infections of the oral cavity and the throat.