## 4 Conclusions  
Novel alginate-based formulations with a silver-containing, zirconium phosphate-based additive, Alphasan RC 2000 have been obtained and extensively tested. The formulations pass all the normative requirements for alginate, or in general, hydrocolloid impression materials, as per the ISO 21563:2021 [32] standard in terms of all the setting and mechanical properties. The thesis placed at the very beginning of this work has confirmed that an alginate material containing a bacteriostatic agent based on silver-containing ceramics can be produced. The materials showed a bacteriostatic effect visible by the formation of an inhibition zone of the growth of _Streptococcus mutans_, increasing proportionally to the AlphaSan content. It shows that the strength of the bacteriostatic activity can be tuned based on the material requirements, such as the storage time of the impression.  
The alginate material that was tested in this work would be a very desirable product in dental practice. Currently, after excretion, it must also be disinfected before casting a gypsum model. Before this step, the impression is a hazardous material with biological contamination that requires appropriate treatment. The addition of silver ceramics would mean that such material, after being rinsed in water, would probably not be a source of dangerous bacteria.  
The second important issue is the influence of the alginate impression disinfection process on the stability of their dimensions. During this time, some materials absorb water or release it, which then affects the accuracy of dimensions [2; 3; 8; 14]. Therefore, eliminating this step would be highly desirable.  
The conducted research, however, has some limitations. Only one type of microorganism was used to test the antimicrobial effectiveness. Other species may also be found in the oral cavity. In our further work on this type of alginate materials, it will also be necessary to test other concentrations of AlphaSan materials and compare them with other materials with bacteriostatic properties. Therefore, further work is needed in this direction. In addition, these alginate materials should be tested for health safety, which requires another test palette, i.e., cytotoxicity and irritant testing.  
Next, this type of materials should be subjected to ageing tests. However, before the material goes on the market, dentits should test it in terms of its functional properties. It would be necessary to carry out in vivo tests by taking a certain number of impressions using the X1 material and checking whether there are any microorganisms on their surfaces through appropriate microbiological tests. Finally, it is required to meet all legislative requirements for example in the EU or US (MDR certification). At the same time, new material from Class 1 Med Dev would have to be classified as Class 3 (containing medicinal materials).  
Conceptualization, Z.R.; data curation, Z.R., M.M., D.B. and D.P.; formal analysis, Z.R., M.M., D.B. and D.P.; investigation, Z.R., D.B., D.P. and R.E.P.; methodology, Z.R. and D.B.; project administration, Z.R. and R.E.P.; resources, Z.R.; software, Z.R., D.B. and D.P.; supervision, Z.R. and R.E.P.; validation, Z.R.; visualization, D.B.; writing--original draft, Z.R., M.M., D.B., D.P. and R.E.P.; writing--review and editing, Z.R., D.B. and R.E.P. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
All the obtained results and data are available in the manuscript and on the request to corresponding authors.  
The authors declare no conflict of interest.