The Investigation of the Effect of a-Tomatine as a Novel Matrix Metalloproteinase Inhibitor on the Bond Strength of Sound and Eroded Dentine through In Vitro and In Silico Methods

Round 1

Reviewer 1 Report

This study aimed to examine the effect of a-tomatine, a new matrix metalloproteinase inhibitor for enhancing bonding strength via in-vitro methods. Very comprehensive investigation and development starting from molecular docking. Some comments as follows:

1. Please comment on Table 1 the predicted full range of dose-response and application time course in the discussion.

2. Table 5 and 6 has a lot of repeated (redundant) data- there must be a better way to present the different p value than the current format.

3. Please discuss about the limitation as an in-vitro study and the expected challange when applying in vivo.

4. The conclusion in the main text can be more concise...

Overall good but minor edits may be needed.

Author Response

Dear Reviewer 1, 

Your valuable comments, your appreciation, and your finding almost all parts of the article sufficient are greatly appreciated. We take all your suggestions and criticisms into consideration and hope to further improve our article accordingly during this revision process. We are grateful.

Please see the attachment

Yours faithfully,

Author Response File: Author Response.docx

Reviewer 2 Report

This is a simple, typical bond strength study with an addition of a computational part (molecular simulations) on the effect of MMP-inhibiting compounds on dentine bonding. There are many points that should be revised.

Introduction: First the problem should be stated and then describe the molecular docking etc. Ln 43-48: This matches the aim of the study which is repeated at the end of the discussion. Delete. Ln 50: Here there are statements on dental erosion. It is not clear if these apply only for this type of substrate (i.e., prolonged exposure to acidic pH) or the same apply, as well, for the sound substrate subjected to momentary acid conditioning treatments for resin bonding.

Materials and Methods: Number of specimens per testing group is small (n=7). In the reference the authors cite (ref 17) for the power analysis they have performed, 10 specimens have been used per group. This is an important limitation, considering the tissue variance. The guidelines for micro-tensile bond strength studies with dentine, suggest the preferable use of 8-10 specimens per group (Armstrong et al, 2016). ln 116: Table 1 footnote. Check if these references correspond to what is cited here. ln 119: Why a total-etch system was selected for bonding to dentine, when the strongly acidic phosphoric acid treatment is well known that it destabilizes collagen, releases metal ions, and activates MMPs? There is ample of evidence that mild pH self-etching systems demonstrate better bond durability with dentine. This is important, especially for the treatment of acid-eroded dentine. ln 126-128: The light-intensity and irradiation times used for photopolymerization of the restorative materials are missing. ln 141 Table 2: Needs editing (unacceptable arrangement). ln 143-207: This part of molecular simulations should be considerably shortened. The entire part of these simulations deals with the chemical affinity of the MMP inhibitors tested with MMR-2,8 and 9. The main question is whether the modified MMP enzymes (after computational “docking” of the inhibitors) still retain residual reactivity with type I collagen. This would be the most important issue to be searched by the simulation and not simply the affinity of the inhibitors with the specific MMPs. ln 208: The bond strength study includes three independent parameters: Type of inhibitor (a-tomatine, CHX, control), type of substrate (sound, eroded dentine) and storage conditions (24h, 6 mo). Clearly define for which comparisons ANOVA (and what type of ANOVA) was used and why a t-test was selected for paired comparisons, rather than using a factorial analysis, assessing the individual and interactive effects of the independent parameters

Results: ln 220: First provide the bond strength data and then the failure mode analysis. For this simple bond strength study, the lack of detailed information on the interfacial topography at higher resolution (i.e., SEM imaging even of debonded dentine surfaces) does not allow reliable assessment of several of the claims made in the discussion. ln 244: The results of molecular docking, should be considerably shortened and thoroughly revised. Please see the study of Guo et al, 2023 (doi:10.1038/s41598-023-35382-3) for a concise and efficient way of presenting such data.   

Discussion: ln 333-339: Note that in all the cited studies total-etch techniques were used, with the limitations discussed above. The discussion is extremely extensive (and chaotic in several parts) without thoroughly addressing the most important part of the study, which is the bond strength (and certainly not the docking mechanism which may apply as an explanatory means of the documented action). Is tomatine toxic to the odontoblasts (note that it has been associated with some toxic effects)? Why this glycoalkaloid with a molecular mass almost twice than CHX is not expected to present the limitations of the latter discussed in ref 66 (ln 328)? Is there a possibility that the complex carbohydrate chain of this molecule may interact with acidic primers (mainly carboxylic or phosphate groups)? Such questions should have been addressed in the discussion rather than presenting scholarly details of the docking models, which may eventually apply. An overall question on this issue is why the group of MMP inhibitors has not granted, so far, a universal acceptance in clinical dentistry, when positive documentation exists for more than 10 plant-derived compounds in the field.

References: Many references should be revised (years, volumes, pages missing)

Author Response

Dear Reviewer 2,

We are deeply appreciative of your valuable and comprehensive review. Thanks to your input, our paper is becoming academically and scientifically enriched, significantly improving its quality and positioning itself as a valuable milestone for future research. We have been actively seeking to incorporate all your suggestions and criticisms to achieve maximum enhancements in our paper. We sincerely hope that this revision earns your approval and appreciation.

Please see the attachment

Yours faithfully,

Author Response File: Author Response.docx

Reviewer 3 Report

1. In the paper, it is suggested that a concise title should be added under the structure of Chlorhexidine and alpha-Tomatine, labeled "Figure-1" (or appropriate number), so that readers can reference and refer to the chart

2. In the discussion section, the author provides a detailed description of the experimental results, including sections 4.1 to 4.4. However, according to academic writing norms, it is recommended that the content of these experimental Results be integrated into the "Results" section to ensure consistency and logical coherence in the structure of the paper.

3. It is recommended to remove the last semicolon from the keyword list. Such modification will further improve the standardization and accuracy of the paper.

4. The phrase about matrix metalloproteinase (MMP) appearing in 2.5.1.2 is not perfect. It is recommended that matrix metalloproteinase (MMP) be mentioned in the relevant section at the beginning of the article, and then "MMP" may be used in place of matrix metalloproteinase in subsequent texts.

5.You mentioned "310°K" as a unit of temperature in section 2.5.2.2 of the article, which is incorrect. It is recommended that "310°K" be corrected to "310 K" to ensure accurate use of temperature units. Please note that it is important to use units and symbols accurately in academic writing to ensure accuracy and normativity of expression.

Author Response

Dear Reviewer 3,

We are grateful for your suggestions. Thanks to these critiques and corrections, our paper is becoming more academically valuable.

Please see the attachment

Yours faithfully

Author Response File: Author Response.docx

Reviewer 4 Report

Good paper with correct methodology.

The references are appropriated.

The conclusions are correct. 

The  limitations of this study should be added, if any. 

Author Response

Dear Reviewer 4,

We are deeply grateful for your valuable feedback and suggestions. Your appreciation of our manuscript, as well as your recognition of the appropriateness and significance of the methodology and findings, are greatly appreciated.

Please see the attachment

Yours faithfully,

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The revised version has been improved.