Protection against Dental Erosion and the Remineralization Capacity of Non-Fluoride Toothpaste, Fluoride Toothpaste and Fluoride Varnish

Round 1

Reviewer 1 Report

The article under review aims to analyze the remineralization capacity of non-fluoride, fluoride toothpaste and fluoride varnish and their protective properties against erosion. Dental erosion is a common problem due to increased consumption of acidic drinks which have a high potential to cause enamel demineralization.  However, the article has some shortcomings.

1. Moderate English changes are required.

 

2. The number of the teeth used in the study is extremely low, 1 tooth = 1 group, which means that the results obtained may be related to some individual features of a tooth.

 

3. “Eight human teeth with no caries and defects, were extracted for periodontal reasons. Following the extraction, the soft tissue residues were removed from the teeth and analyzed to find any fractures.”

What magnification was used to analyze surface quality?

 

4. Was the use of the extracted teeth for research approved by an ethics committee and did the patients give their written informed consent?

 

5. "The samples were cut with a high-speed diamond bur and water irrigation at the level of the enamel-dentin junction and then sectioned, to have the flat surface opposite to the treated one. To make the surfaces uniform, the samples were polished with silicon abrasive tips (5)."

Please add a figure/figures demonstrating the steps in samples preparation and at least one picture of one of the samples. Thus, it will be easier for the readers to understand what was done.

 

6. The authors stated that "Samples G2, G3, G4, G5, G6, G7, G8 were immersed in 5 ml of soft drink for two minutes at room temperature and then they were rinsed with distilled/deionized water. The immersion process is repeated four times for a total of eight minutes." 

Please add a reference for this demineralization method.

 

7. The authors stated that “The different products were applied in the same way: they were placed in contact with the enamel surface for three minutes at zero hour, and after 8, 24 and 36 hours.”

Please add a reference for this product application method.

 

8. "Samples “3” and “6” were treated with a not-fluoride toothpaste; samples “4” and “7” were treated with a 1450 ppm of fluoride toothpaste. Finally, samples “5” and “8” were treated with single 0,5 ml doses of professional fluoride varnish, that are specific for dental hypersensitivity and contain 22600 ppm of fluoride."

Please provide more detailed information about the products used in the study and their composition. In the Introduction section, the authors stated that “While the hydroxyapatite is dissolved in acidic environment, the fluoride makes the solution extremely rich in fluorohydroxyapatite. The fluoride is absorbed by the crystals on the surface, thus attracting calcium ions. Apatite without carbonates is less soluble, so in case of demineralization it will replace the original mineral.” Did the authors compare the HAP-containing product and fluoride-containing products?

9. In my opinion, the list of references is too short. Dental erosion is a very common problem, and there are a lot of interesting studies that may be considered in the Discussion section.

Author Response

Dear Reviewers,

 

thank you very much for taking your time to revise our paper.

We red all the comments and suggestions made and we reviewed our manuscript according to your precious comments.

 

Once again, thank you for your time

Best regards

 

The Authors

 

 

Reviewer 1:

 

1. English was checked and errors were corrected
2. The number of teeth used is 8 and not 1. This information is stated in the materials and methods part, first line. Each tooth underwent the procedure subsequentely, and after each step it was analyzed. That is also why the statistical analysis provided was a Dunnet T test for paired data.
3. The magnification used was 600X, 1500X and 3000X. This information can be found in figure 2. During the sem analysis, presence of fracture was searched.
4. Ethical approval was waived by the ethic committee as the extracted teeth were extracted for periodontal reasons, so they needed to be extracted regardless of this study.
5. Unfortunately, we do not have any photo of the preparation process. Nevertheless, the followed methodology is well known in the dental “in-vitro” study, and we strictly follow the methodology already published in literature.
6. Reference of this methodology is already present in our paper: this information can be found in reference number 5.
7. Reference is the same as above, number 5
8. Hap containing products were not compared with fluoride containing products, this is not the aim of our study, but surely it is a great idea for the next study, according to the fundings that we will receive for 2023.

The brand of the used products was not used nor written on purpose: we do not want to make good/bad advertisement to the specific brand. For the aim of this study, just the fluoride content was written. Some references were added, we will be happy to add suggested references if you want.

Reviewer 2 Report

The paper itself is well written and documented, showing a great effort from the authors.

The topic sounds original and with an interesting clinical meaning.

I also would make only the following few mentions:

-          Please check the name of the authors? Is Roberta Gaia Parcianello an author? She doesn’t compare in the authors list in the manuscript.

-          The methos applied seems appropriated and well described.

-          I would suggest the authors to add some imagines of the prepared teeth.

-          Maybe a bigger sample (more than eight teeth) could better confirm the conclusions.

Author Response

Dear Reviewers,

 

thank you very much for taking your time to revise our paper.

We red all the comments and suggestions made and we reviewed our manuscript according to your precious comments.

 

Once again, thank you for your time

Best regards

 

The Authors

 

Reviewer 2

 

1. The Name of Roberta Gaia Parcianello now appears also in the Author’s list in the manuscript
2. Thank you
3. Unfortunately we do not have images of this kind
4. This is very true, for this study specifically we could not collect more than 8 specimens, Thank you

Reviewer 3 Report

Dear Authors and Editor see my commnets in file

Comments for author File: Comments.pdf

Author Response

Dear Reviewers,

 

thank you very much for taking your time to revise our paper.

We red all the comments and suggestions made and we reviewed our manuscript according to your precious comments.

 

Once again, thank you for your time

Best regards

 

The Authors

 

 

Reviewer 3

 

Abstract

 

• Demineralization process was better explained in the abstract
• The word “attack” was changed with the word “interactions” as suggested
• Thank you

 

Introduction

 

• Line 50 was modified as suggested
• Line 74We added this information
• We added more informations regarding this topic and we added the requested references
• Line 81: we made the requested modification
• Line 85: we made the requested modification
• Line 90: we made the requested modification
• Line 93: we made the requested modification

 

Materials and methods

 

 

• Is was not a blade, a high speed diamond rotary bur. This is a kind of dental bur used in a high speed dental device:30000 rpm) This information is not in text because we used the same method used in the study of reference 5. Usually, these devices have a standard speed and it is not necessary to add this informations. Of course, if you really want to, we will add this information in text. The brand of the used bur has been added. Thank you
• Ethical approval was waived by the ethic committee as the extracted teeth were extracted for periodontal reasons, so they needed to be extracted regardless of this study. This information has been added in text.
• Enamel vary from person to person, but every single tooth, after being cut, underwent a surface standardization process. This is explained in the materials and methods section.
• Line 106: this information have been added, as suggested, thank you.

Fluorine content is well written in text, The brand of the used products was not used nor written on purpose: we do not want to make good or bad advertisement to the specific brand. For the aim of this study, just the fluoride content was written.

• Line 145: this information has been added as suggested
• Line 152: his information has been added as suggested
• Table 2: you are right, but as standard deviation was calculated in an excel table and it gives back this number automatically, we cannot erase numbers after the comma. To do that we should calculate the standard deviation with a calculator and write it down on the table, which is not the correct method.
• The Y axis represent the profilometer measurements, as stated in text.
• Figure 2 have been moved into the results section

 

 

Discussion

 

Yes, Thank you

Line 280 have been removed as suggested

 

References

Modifications have been made following your advices

Round 2

Reviewer 1 Report

1.     Moderate English changes are still required.

 

2.     The number of teeth used is 8 and not 1. This information is stated in the materials and methods part, first line. Each tooth underwent the procedure subsequentely, and after each step it was analyzed. That is also why the statistical analysis provided was a Dunnet T test for paired data.

 

“Eight healthy human teeth with no caries and /or defects, were extracted for periodontal

reasons….. The samples were cut with a high-speed diamond bur (K G ®)

and water irrigation at the level of the enamel dentin junction and then sectioned, to have

the flat surface opposite to the treated one. To make the surfaces uniform, the samples

were polished with silicon abrasive tips (5) According to the adopted procedure, samples

were divided into 8 groups.”

 

From this paragraph I can see that 8 teeth were divided into 8 groups, which means that in each group only 1 tooth was analyzed (1 tooth per 1 group) and the results may be influenced by individual features of a particular tooth. If I got this wrong and from each tooth you prepared several specimens and assigned them to different groups, then please describe what you did in a more clearcut manner.

  

3.     The magnification used was 600X, 1500X and 3000X. This information can be found in figure 2. During the sem analysis, presence of fracture was searched.

 

In Figure 2 we can find information about magnification that was used for SEM analysis of the prepared samples.

 

However, my question was about your analysis of the extracted teeth.

You wrote “Following the extraction, the soft tissue residues were removed from the teeth and analyzed to find any fractures.” Let me repeat my question: What method and what magnification did you use to find fractures at this step? Please add this information.

 

 

4.     Reference of this methodology is already present in our paper: this information can be found in reference number 5.

5.     Reference is the same as above, number 5

 

You should insert this reference (5) after the following sentences: “Samples G2, G3, G4, G5, G6, G7, G8 were immersed in 5 ml of soft drink for two minutes at room temperature and then they were rinsed with disti lled/deionized water. The immersion process last about 2 minutes and it is repeated four times for a total of eight minutes. The three different products were applied, without being brushed, to cover the entire surface of the enamel of some groups of samples, and then they were rinsed with distilled water.”

“The different products were applied in the same way: they were placed in contact with the enamel surface for three minutes at zero hour, and after 8, 24 and 36 hours,”

because all of the above sentences quote information from the study by Lombardini et al. Otherwise the readers will not be able to understand it.

6. The brand of the used products was not used nor written on purpose: we do not want to make good/bad advertisement to the specific brand. For the aim of this study, just the fluoride content was written.

Apart from fluoride content, effectiveness of the product may depend on a variety of factors, e.g., type of fluoride compound or other additives in the composition of a toothpaste. There is no need to name the brand, but it’s very important to present information about complete composition of the product used. It may be presented in a separate table.

 

Author Response

Dear Reviewer,

once again thank you for your comments.

We will try to answer all your comments following your suggestions.

 

1. We revised the paper with the help of a native English speaker
2. I will try to better explain myself here: we extracted 8 teeth and each one of them was assigned to a different group. But, during the analysis each tooth was divided (into the SEM) in 8 different smaller areas. This was made due to the lack of possibility to have more healthy teeth available, and in order to decrease the chance to have influenced results. We totally agree with you about the fact that a larger number of specimens would be even better, but unfortunately it was not possible to collect more teeth. Dividing the surface was a method that we used to decrease the effect of the lack of availability of human teeth.
3. Yes, sorry. At first, we did not understand the question. We added this information in the new revised manuscript.
4. OK, we inserted this reference where you suggested
5. OK, we inserted this reference where you suggested
6. We added this information adding table 2.

 

 

 

Once again, thank you

Best regards

The Authors

Author Response File: Author Response.docx