Antimicrobial Poly (methyl methacrylate) with Silver Nanoparticles for Dentistry: A Systematic Review

Round 1

Reviewer 1 Report

The topic is interesting but the work should be improved:

• Line 16 - C. albicans and other bacteria such as... - please rephrase
• Line 24 - please use italics for Candida albicans
• Line 37 - I think it should be "pathogenic microorganisms"
• Line 50 - when using keyword "antimycotic" in ScienceDirect (years 2010-2019) there is 9,986 results, whereas for "antifungal" there is 52,783 - maybe it would be good to use the more popular synonym in survey to find more interesting works?
• Please use dot for "et al.
• Table 1 - column Material properties - they are rather methods for deermining of the properties. The same for antimicrobial effect should rather show what antimicrobial activity materials had and not by what methods these properties were tested. What's more, the table is difficult to read, I suggest changing it, introducing a uniform background, lines.
• Silver nanoparticles are usually a colloidal form of silver, please explain how ions are released from it?
• Line 140 - "The antimicrobial effect of silver nanoparticles can be induced by the formation of ROS or by the releasing of silver ions from the material tested" how it actually affects microorganisms, their metabolism, growth?
  
• Figure 3 - it seems to me that the picture presents various species of the genus Candida on a chromogenic agar? If I'm wrong, and only C. albicans can be seen, please add information on what medium it is, and why is the color of the colonies different? No zones of growth inhibition around the discs - does this indicate antimicrobial properties?
• What are the advantages of PMMA over other polymers used in dentistry? Are any other nanomaterials added to dental PMMA?
   

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

In this review, the authors describe the use of Ag-PMMA materials for use in dental applications to counter microbiological infections. The subject is interesting for the readership of Appl Sci, but I recommend publication only after addressing the comments below. In a nutshell, I think the authors should share more scientific insights about the subject than what is currently written down.

The essential components for a review are present: there is a results table and all of the included works are discussed in table and text. The authors describe the methodology well. What I could not find clearly was a clear narrative or opinionated red thread throughout the text. I understand the paper is about reviewing results from literature, but I was hoping to learn more overarching insights about the subject than a simple description of what was done in a paper. In my impression, the authors work in this particular field and should have much more scientific knowledge and insight on the subject than what is displayed here. I'm sorry to say that there seems at this point little more than a compilation of paper abstracts.

For instance, the authors discuss pmma synthesis and different Ag NP embedding strategies only very briefly, which allows questions to be invoked in the reader's mind that do not get an answer. Can you please add a paragraph to discuss, in your opinion, what works best as an embedding strategy and why? What factors in the pmma synthesis seem to be crucial for the antimicrobial functionality? Are different material properties required for different kind of implantates/cements? What would the ideal pmma-AgNP material look like?

As I read throughout the results I also wondered how well each of the methods and results can be compared. It seems to me that each work has a different way of manufacturing the pmma, different size & surface chemistry of the Ag NPs, testing for biocompatibility, and testing for antimicrobial properties. Can you discuss why you think you can compare the results? Can you recommend to authors in your work field what essential tests are necessary to conclude on biocompatibility and antimicrobial properties? Is it important for the field to have a standardized way of testing? What can you recommend for your colleagues in this field? Are there any pitfalls you have encountered in your own work that you can share with the community?

What I'm also missing at this point is an outlook for this particular field. Are there any pmma-AgNP conjugates being used in dental clinics right now, and if not, how far into the future can we expect such products appear in the clinic? In what development phase is this technology? What needs to be done at this moment in the work field to make pmma-AgNP materials to a success for dental applications? What crucial research questions need to be addressed in the near future?

Finally, in line 134 the authors mention the work of light-activated Ag-NP treatment. What kind of effects arise from the light irradiation, particularly? I'm missing a description why this would work better.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Lines 16-17: The names of bacteria must be written in full.

Table 1: The abbreviations must be detailled at the bottom of the table.

Antimicrobial effect section: The names of bacteria and fungi must be written in full when mentionned for the first time.

Conclusions: The authors should provide their opinions and remarks about the use of poly(methyl methacrylate) with silver nanoparticles in dental application.

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The Authors have significantly improved the manuscript, however some corrections are still necessary:

 

1. Abstract line 16 - please rephrase as: Candida albicans and bacteria.....remove another
2. line 142 - Escherichia
3. line 132 - et al.
4. Figure 3 description - please use italics for latin names

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The author's responses to my previous questions are excellent and I agree with them. In fact, they add so much to the story, and take away much of my confusion, that I would highly encourage the authors to add most of the responses from the revision letter into the manuscript (most of them can be directly included without much editing). Right now only ~25% is added, and it would be nice if that would be >75%. In the end, it is better to answer my questions not just to me, but to all of the readers. This would truly add crucial details that are important for the readers and your colleagues. When these are added I recommend publication in Applied Sciences directly.

Author Response

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Author Response File: Author Response.docx