Mechanical Behaviors of a New Polymer-Based Restorative Material for Immediate Loading: An In Vitro Comparative Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper describes a comparative study of two materials used as part of a dental implant system, one a regular PMMA formulation in current use and the other a commercial material new to the market.

I can only comment on this as a polymer scientist – I an not a dental expert.  I understand this to be part of a conference special edition, otherwise I would have suggested that the work would be better submitted to a dental materials journal.

Having said that, as far as I can judge, this is sound work,  The paper is well written and easy to follow.  The tests seem appropriate and the conclusions are well supported by the experimental data.

I would be happy to see this published, though I would suggest a few minor corrections:

PMMA is more correctly (according to IUPC recommendations) written as poly(methyl methacrylate)

Line 232, “it was no statistically significant different” would read better as “there was no statistically significant difference”

Throughout the paper I worry about the way mean data are presented.  The authors quote numbers like 1953.19 ± 543.73.  Given that the errors are large, why quote the mean to so many significant figures?  It would be better to write e.g. 1950 ± 540.

Author Response

Comment: This paper describes a comparative study of two materials used as part of a dental implant system, one a regular PMMA formulation in current use and the other a commercial material new to the market.

I can only comment on this as a polymer scientist – I an not a dental expert.  I understand this to be part of a conference special edition, otherwise I would have suggested that the work would be better submitted to a dental materials journal.

- Response: Dear reviewer hanks a lot. It is a privilege to receive a review from a polymer scientist. Just for your understanding, I sent the paper in advance to the journal and I receive an invitation to submit the paper to a specific dental speech tissue: Technical Applications of Oral Health and Clinical Dentistry. So I agree with you and this special issue is related to the dental filed. Thanks.

Comment: Having said that, as far as I can judge, this is sound work,  The paper is well written and easy to follow.  The tests seem appropriate and the conclusions are well supported by the experimental data.

- Response: Thanks a lot.

Comment:I would be happy to see this published, though I would suggest a few minor corrections:

PMMA is more correctly (according to IUPC recommendations) written as poly(methyl methacrylate)

Response: Done. Your suggestion has been applied throughout all the manuscript.

Comment: Line 232, “it was no statistically significant different” would read better as “there was no statistically significant difference”

- Response: Done.

Comment: Throughout the paper I worry about the way mean data are presented.  The authors quote numbers like 1953.19 ± 543.73.  Given that the errors are large, why quote the mean to so many significant figures?  It would be better to write e.g. 1950 ± 540.

Response: Honestly I always used this format. Moreover, another reviewer suggested to use two decimals in all the numbers. So, I regret to the editorial office. Thanks a lot.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript describes a new material for dental goal.

Generally, the research, presented in the manuscript is correct and contains no questionable point.

However, there is a question: even need dentists in new materials. I asked some working dentists, and they answer that modern materials used now in praxis, satisfy all necessary requests.

On this reason, I believe that the authors have to demonstrate what are the real advantages can be obtained by use the proposed material in praxis.

Author Response

Comment: The manuscript describes a new material for dental goal.

Generally, the research, presented in the manuscript is correct and contains no questionable point.

- Response: Thanks a lot.

Comment: However, there is a question: even need dentists in new materials. I asked some working dentists, and they answer that modern materials used now in praxis, satisfy all necessary requests.

On this reason, I believe that the authors have to demonstrate what are the real advantages can be obtained by use the proposed material in praxis.

- Response: Dear Reviewer, I completely agree with you that modern materials could satisfy all necessary requests in clinical practice. However, there are several considerations. The first is that quite all the modern materials steel needs long-term evidence. Unfortunately, in dentistry, marketing became before evidence.  For example, the tested polymers is a new material (in the market since a few months), but it needs evidence. Second points, digital dentistry involved all the world including dentistry. Industry are looking for digital materials to replace conventional analogs. In the discussion we focused on the benefits of this new material (no metal reinforced). Quite all the discussion is oriented to evaluated the clinical performance of the new material comparing to the gold standard, given benefits and limitations.

I hope it is enough. Thanks for the good question.

Reviewer 3 Report

Comments and Suggestions for Authors

1 The literatures cited in the manuscript should be marked in order in the text. For example, literature [4] didn't appear before literature [5] in the text. Similarly, [6] didn't appear before [7]. It should be corrected.

2 In line 116, it is described that, one year of mastication is 365,000 cycles, please give some references to confirm it.

3 In line 158, the kind of the resin should be made clear. Is it PMMA?

4 the printing parameters, especially the infilling density of the prototype should be given in line 156.

5 In lines 193 & 196, Instron, a manufacturer of the testing machine, was mentioned twice. One is written as "Instron", the other is "INSTRON", the format is inconsistent. In addition, the second can be deleted.

6 In line 208, "were to" should be corrected to "was to".

7 In figures 7 & 8, there is a symbol of "." after each number in the Y-axis, it should be deleted.

8 In the whole manuscript, the significant figures were inconsistent. For examples, there are two numbers after the symbol of “.” for the "1953.19" in line 231, while one number for the "2504.6" in line 257, and no number for the "3382" in line 258. Especially, the “3382±578.5” in line 258 is a wrong expression way.

9 In line266, what is the definition of η2? How to get its value?

10 It had better give more information on the composite "ONLY", such as the particle size of leucite and the molecular weight of PMMA, as we know, they both have effects on the mechanical properties of the composite.

11 Being blank, the second line in Table 1 should be deleted.

12 “a mean loading value of 1400±274 N and displacement of 1.21±0.13” in line 239 can not be confirmed in Figure 7, How to explain the difference?

13 In Figure 10, what do “group 1” and “group 2” stand for? Which one is the ONLY composite, and which one is the reinforced-PMMA?

14 the conclusions have been drawn too simply, they should be modified.

Author Response

Comment 1: The literatures cited in the manuscript should be marked in order in the text. For example, literature [4] didn't appear before literature [5] in the text. Similarly, [6] didn't appear before [7]. It should be corrected.

- Response: Thanks a lot. Literatures have been fixed in the manuscript.

Comment 2: In line 116, it is described that, one year of mastication is 365,000 cycles, please give some references to confirm it.

- Response: 2 References have been added and literature fixed in the test.

Comment 3: In line 158, the kind of the resin should be made clear. Is it PMMA?

- Response: Type of resin for prototype models has been reported (Polycarbonate-like)

Comment 4: the printing parameters, especially the infilling density of the prototype should be given in line 156.

- Response: Honestly I don’t know this data. However, prototype models are not the tested materials. Nevertheless, I have added the web site with the technical sheet. 

Comment 5: In lines 193 & 196, Instron, a manufacturer of the testing machine, was mentioned twice. One is written as "Instron", the other is "INSTRON", the format is inconsistent. In addition, the second can be deleted.

- Response: Thanks. I use same format in all the manuscript and the second INSTRON was deleted.

Comment 6: In line 208, "were to" should be corrected to "was to”.

- Response: It has been done. Thanks a lot.

Comment 7: In figures 7 & 8, there is a symbol of "." after each number in the Y-axis, it should be deleted.

- Response: Thanks a lot. It is the true. However, in the original .docx file there is no any “.”. So I ask to the editorial office to check.

Comment 8: In the whole manuscript, the significant figures were inconsistent. For examples, there are two numbers after the symbol of “.” for the "1953.19" in line 231, while one number for the "2504.6" in line 257, and no number for the "3382" in line 258. Especially, the “3382±578.5” in line 258 is a wrong expression way.

- Response: Ok. This is because the last number/s is/are zero. I learned this by a friend of mine, editor of an USA journal. However, I fixed it in the manuscript. Thanks.

Comment 9: In line266, what is the definition of η2? How to get its value?

- Response: Thanks. I added a foot note. “ The η2 is a squared measure of association defined as the ratio of variance in an outcome variable explained by a predictor variable, after controlling for other predictors.”

Comment 10: It had better give more information on the composite "ONLY", such as the particle size of leucite and the molecular weight of PMMA, as we know, they both have effects on the mechanical properties of the composite.

- Response: Thanks a lot. I cited a previous manuscript with several characteristics of the used material and I add the following: "The mean average molecular weight of PMMA is ~350,000 by gel permeation chromatography (GPC) analysis. The inorganic percentage is about 10-12%. Ratio between alumni and leucite depends by color. Composition of leucite is the follow: SiO2 70–75%; Na2O 12–15%; K2O 0–1.5 %; CaO 7–12 %; MgO 0–5%; Al2O3 0.1–2.5%; Fe2O3 0–0.5%. In the control group, conventional titanium reinforced PMMA was used (PMMA group)."

Comment 11: Being blank, the second line in Table 1 should be deleted.

- Response: It was done. Thanks.

Comment 12: “a mean loading value of 1400±274 N and displacement of 1.21±0.13” in line 239 can not be confirmed in Figure 7, How to explain the difference?

- Response: In the future we reported an explanatory example of 1 sample for group, no the mean values. In order to make easier to understand, I added the following sentence. “ An example graph of break points in test and control groups are reported in figures 7 and 8, respectively. ”

Comment 13: In Figure 10, what do “group 1” and “group 2” stand for? Which one is the ONLY composite, and which one is the reinforced-PMMA?

- Response: Yes. I modified the figure. Thanks.

Comment 14: the conclusions have been drawn too simply, they should be modified.

- Response: Conclusions have been rewritten. Thanks.

Reviewer 4 Report

Comments and Suggestions for Authors

Pisano discussed the Mechanical Behaviors of a New Polymer-Based Restorative Material for Immediate Loading: An In-Vitro, Comparative, Research in this manuscript. Before publish, some necessary modifications need to be completed.

1. Some sentences have grammar issues, please check and revise them in a timely manner.

2. The abstract section needs to be streamlined, it is too complex, and should present the most eye-catching results in the simplest way possible.

3. Some testing methods are not detailed enough, please provide specific testing parameters.

4. What is the innovation and originality of this research, and what are its advantages compared to traditional methods.

5. Images and tables are not standardized.

6. The conclusion needs to be rewritten, it's too simplistic.

Comments on the Quality of English Language

moderate revision

Author Response

Pisano discussed the Mechanical Behaviors of a New Polymer-Based Restorative Material for Immediate Loading: An In-Vitro, Comparative, Research in this manuscript. Before publish, some necessary modifications need to be completed.

Comment 1: Some sentences have grammar issues, please check and revise them in a timely manner.

- Response: It was done, also thanks to all the reviewers.

Comment 2: The abstract section needs to be streamlined, it is too complex, and should present the most eye-catching results in the simplest way possible.

- Response: The abstract has been revisited accordingly.

Comment 3: Some testing methods are not detailed enough, please provide specific testing parameters.

- Response: Dear reviewer, also according to the other reviewers I think the test are detailed enough considering that this is a dental special issue, and the readers dentists. I hope you agree, Thanks.

Comment 4: What is the innovation and originality of this research, and what are its advantages compared to traditional methods.

- Response: Introduction, and all the discussion are focusing on the drawbacks of the gold standard method (actual) and potential benefits of this new composite polymers. In brief for your convenience, the tested material is new and it can be used without meta-reinforcements, with several potential benefits.

Comment 5: Images and tables are not standardized.

- Response: Dear reviewer, I checked the instruction for authors. There are not specific guidelines to standardized the figures and tables. However, as reported in the guidelines, the Editorial Office reserves the right to request original, uncropped, and unadjusted images upon submission. Thanks.

Comment 6: The conclusion needs to be rewritten, it's too simplistic.

- Response: Conclusions have been rewritten. “With the limitation of this in vitro study, the novel composite polymer showed similar mechanical features under static and dynamic load compared to conventional, metal-reinforced, PMMA. However, further clinical researches are needed to confirm this preliminary, in-vitro, results.”

Round 2

Reviewer 4 Report

Comments and Suggestions for Authors

accept