Pre-Disinfection of Poly-Methyl-Methacrylate (PMMA) Reduces Volatile Sulfides Compounds (VSC) Production in Experimental Biofilm In Vitro

Round 1

Reviewer 1 Report

In this paper Authors investigated pre-disinfection of PMMA on malodor formation. 

Paper is well written, however in my opinion Authors made one mistake that led to incorrect conclusions. Namely, Authors disinfected PMMA discs by soaking for 10min in commercially available mouth rinsing formulations. Then, discs were rinsed with water prior the further experiments. In my opinion, rinsing with water was not enough to remove disinfectant that diffused into material. Afterward this diffused disinfectant was the main reason for malodor reduction. In real environment, disinfectant would leach from material during usage. Authors, should repeat experiment with samples where disinfectant was thoroughly washed (soaked in water or some other medium from prolonged time). Authors may check (by HPLC) how much disinfectant was left in the samples after just water rinsing and if it is negligible then they do not have to repeat experiments. However, I believe that non negligible amount of disinfectant was present in the samples.   

Author Response

Dear Reviewer

Thank you very much for your remarks on my manuscript. It is true what you mentioned regarding the absorption of active disinfectant inside the the pmma discs. That point was beyond the scope of the original article. Although it is mentioned that the material is porous, we didn't consider its capability to absorb the disinfectant. I would like to embrace your idea and incorporate it in the text as a topic for future research. Since, to the best of our knowledge, we encountered no such experiment, there was not enough scope to address the mechanism issue.

Kind regards

Dr. Ofir Rosner  

Reviewer 2 Report

I have reviewed the manuscript entitled “Pre-disinfection of Ploy-Methyl-Methacrylate (PMMA) Reduc-es Volatile sulfides compounds (VSC) Production in Experimental Biofilm in vitro” by Ofir Rosner , nir sterer , Guy Melamed * , Shiri Livne , eran dolev , Gil Ben-Izhack , Hadas Heller , Uziel Jeffet.

The manuscript is globally clear and well structured. I have some suggestions and minor comments.

There is a mistake in the title: “ploy” should be “poly”.

Minor corrections:

line 21: “suggest”

line 176 : “challenges”

line 188: “suggest”

Please complete supplementary materials, data availability and acknowledgment sections with appropriate information.

Concerning the gel electrophoresis, it would have been appropriate to include a size marker. Despite this, could the authors precise which bands have been included in the densitometry analysis?

Concerning the fluorescence analysis of biofilm, results are visually very different between the control (a) and the discs soaked with commercial solutions (c) and (d) on the figure 5. It is astonishing that these results are not statistically significant, according to the authors (line 152). Could authors please discuss this point? Maybe it would be useful to include more details on the quantification that was used.

Authors indicate that PMMA are porous (line 187). As PMMA were rinsed with water after pre-disinfection, it is likely that the observed effect is due to active molecules from soaking solutions present inside PMMA. One can suggest that since saliva is continuously secreted in the oral cavity, the molecules will be progressively eliminated from the PMMA and this effect will fade with time. It would be interesting to discuss this point in a perspective of stability engineering of the active molecules inside the PMMA.

Author Response

Dear Reviewer

Thank you very much for your helpful remarks on my manuscript.

Regarding your first  request, no supplementary materials were added. Appropriate sections were indicated "none". 

Concerning the gel electrophoresis, Fig. 3 was revised to include an arrow indicating the measured band (alpha-amylase, 55KD). This information was added to the figure legends.

Concerning the fluorescence analysis, all tested solutions performed significantly better than the control. The non significant difference (p=0.08) was reported between herbal extract (HE) and chlorhexidine (CHX). These points were further clarified in the text.

regarding your last remark, it is true what you mentioned about the absorption of active disinfectant inside the the pmma discs. That point was beyond the scope of the original article. Although it is mentioned that the material is porous, we didn't consider its capability to absorb the disinfectant. I would like to embrace your idea and incorporate it in the text as a topic for future research. Since, to the best of our knowledge, we encountered no such experiment, there was not enough scope to address the mechanism issue.

Kind regards

Dr. Ofir Rosner  

Round 2

Reviewer 1 Report

Authors should just add one sentence in the conclusion that their future work will investigate materials properties after thoroughly washing. 

Author Response

Hello and thank you again.

I emphasized the matter you brought up in your latest comments and marked them in light marked green to be distinguished from the previous resubmission.

Dr. Ofir Rosner

Author Response File: Author Response.docx