Nanometals and Metal Ion Pollution from Dental Materials in Dental Environment

Round 1

Reviewer 1 Report

A very interesting study about the hazards for the metal exposure of metal personnel. However, there are some issues:

1) Line 40 there are no metallic restoration for chair side restorations

2) Line 53 remove or rephrase the word invisible

3) Line 69 Rephrase

4) Please don't use phrases like "On the otherr hand".

5) Consider to change the title is not informative about the content of the paper

6) There are few grammatical errors. Please go through the entire manuscript and correct them

Author Response

First, thank you so much for your time reading and reviewing our manuscript. We appreciate your meaningful comments and essential suggestions

1) Line 40 there are no metallic restoration for chair side restorations

Thank you for this observation, we modified this sentence to: “This technology allows ceramic restorations to be milled chairside in a same-day visit”. (Line 40)

2) Line 53 remove or rephrase the word invisible

Thank you for pointing it out, we removed the word invisible.

3) Line 69 Rephrase

Thank you for your suggestion. we have rephrased this sentence to: “Slow or high-speed dental drills and ultrasonic scaling dental equipment generate the metal spreading in the dental environment”. (Line 69)

4) Please don't use phrases like "On the other hand".

Thank you for your suggestion. We removed the phrase "On the other hand" from the manuscript. (line 106)

5) Consider changing the title is not informative about the content of the paper

Thank you for your suggestion. We have modified the title to “Metallic Pollution from dental materials on Dental Environment”.

6) There are few grammatical errors. Please go through the entire manuscript and correct them

Once again, thank you for your valuable contributions to improving this manuscript. The text was completed revised, and proofread by a native speaker. Also, the following references were added to the manuscript.

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript reviews the behavior of metallic elements present in dental materials, their routes of exposure, and their potentially toxic effects on the dental personnel, and proposed measures to reduce and eliminate occupational and non-occupational hazards from exposure to metallic ions from dental materials.

The scope is adequate and the content and dissemination order are logic and appropriate. Overall it is of clinical and practical significance.

However, the MS is written for a specialized dentistry journal. For publication in the special issue “Micro- or Nanoscale Materials Sciences and Technology” in journal Micro, a general (micro- and nano-scale) materials science journal, it is necessary to add some materials science content, specifically, underlying material structure and degradation mechanism which leads to metal leaching.

The Tables do not have titles. Line spacing is overly large which results in Tables being long and spilling across pages and thus are hard to read.

In conclusion, a major revision is recommended.

More for consideration:

1. Please also consider metal-reinforced glass ionomer cement in the dental cement category.  

2. L252, when it comes to suggesting alternatives to dental amalgam, this reviewer would like to draw the authors’ attention to a highly impacting publication which states “With 125 million amalgam restorations carried out annually in Europe, the European Commission advocates atraumatic restorative treatment using mercury-free alternatives2, highlighting glass ionomer cements (GICs).” DOI: 10.1038/ncomms9631

So it is reasonable to suggest glass ionomer cement besides composite resins.

3. Since the first thing that comes to people’s mind on metal pollution is dental amalgam, it may be intuitive to introduce in more details its microstructure and possible degradation mechanism. The microstructure and metallic phases present are explicitly elucidated in 10.1016/j.intermet.2009.12.004, which the authors may consider citing.

4. The overall English usage is adequate, except Conclusion. Please rewrite. By “universities” do the authors mean dental education?

 

Author Response

First, thank you so much for your time reading and reviewing our manuscript. We appreciate your meaningful comments and essential suggestions

 

1)The scope is adequate and the content and dissemination order are logic and appropriate. Overall it is of clinical and practical significance.

However, the MS is written for a specialized dentistry journal. For publication in the special issue “Micro- or Nanoscale Materials Sciences and Technology” in journal Micro, a general (micro- and nano-scale) materials science journal, it is necessary to add some materials science content, specifically, underlying material structure and degradation mechanism which leads to metal leaching.

Thank you for your suggestion. We agree and we have described the dental amalgam reaction, structure, and degradation mechanism which leads to metal leaching. (Line 81-86)

 

2)The Tables do not have titles. Line spacing is overly large which results in Tables being long and spilling across pages and thus are hard to read.

Thank you for pointing it out. I have reduced the line spacing in Table 1, Table 2, Table 3, and Table 4.

The titles of each table were adequately revised. The tables titles are:

Table 1. Metallic elements in dental materials.

Table 2. Summary of adverse health effects on dentists, dental students, and dental personnel associated with metal exposure.

Table 3. The potentially toxic effects of metallic elements on humans.

Table 4. Guideline of risk of procedure for metal spread.

 

3)Please also consider metal-reinforced glass ionomer cement in the dental cement category.  

Great observation! Thank you for your suggestion. We have considered metal-reinforced glass ionomer cement in the dental cement category. Based on the article below, we have updated the Table 1-second column.

Recent literature has shown that the properties of GICs have been successfully enhanced by incorporating metal alloys at the nanoscale level (i.e., silver–tin or silver–palladium/titanium) into glass powder.

Amin F, Rahman S, Khurshid Z, Zafar MS, Sefat F, Kumar N. Effect of Nanostructures on the Properties of Glass Ionomer Dental Restoratives/Cements: A Comprehensive Narrative Review. Materials (Basel). 2021 Oct 21;14(21):6260. doi: 10.3390/ma14216260. PMID: 34771787; PMCID: PMC8584882.

4)  L252, when it comes to suggesting alternatives to dental amalgam, this reviewer would like to draw the authors’ attention to a highly impacting publication which states “With 125 million amalgam restorations carried out annually in Europe, the European Commission advocates atraumatic restorative treatment using mercury-free alternatives2, highlighting glass ionomer cements (GICs).” DOI: 10.1038/ncomms9631

So it is reasonable to suggest glass ionomer cement besides composite resins.

Thank you for pointing this out. We accepted your suggestion and modified the paragraph.

72. WHO, Air quality guidelines for Europe. 2nd ed. ed. WHO Regional Publications, European Series; 91. 2000, Copenhagen: World Health Organization. Regional Office for Europe.

 

5). Since the first thing that comes to people’s mind on metal pollution is dental amalgam, it may be intuitive to introduce in more details its microstructure and possible degradation mechanism. The microstructure and metallic phases present are explicitly elucidated in 10.1016/j.intermet.2009.12.004, which the authors may consider citing.

Thank you for your suggestion. We added more details regards the metallic phases and possible degradation mechanism of the dental amalgam. I also cited the suggested paper.

“When the liquid mercury (Hg) is mixed with the metal alloy, the Hg reacts with intermetallic Ag3Sn (γ -phase), forming Ag2Hg3 (γ1 -phase), Sn8Hg (γ2 -phase), and the unreacted alloy Ag3Sn (γ -phase). The γ -phase and γ1 -phase are mechanically strong and γ2 -phase is soft and unstable [36]. Therefore, the dental amalgam degradation may be attributed to γ2 -phase”. (Line 75-79)

 

6) The overall English usage is adequate, except Conclusion. Please rewrite. By “universities” do the authors mean dental education?

Once again, thank you for your valuable contributions to improving this manuscript. The text was completed revised, and proofread by a native speaker. Also, the following references were added to the manuscript. We also rewrote the conclusion.

“Metallic Pollution from dental materials in Dental environments has been more dangerous with the advance of nanotechnology. The nanometals increased the risk of toxicity and absorption. This review found skin and lung disorders are the most harmful effects associated with metallic ions exposure to dentists, dental students, and dental personnel. Therefore, guidelines for risk of dental procedures are encouraged to reduce the daily metal intake through inhalation and dermal/ocular absorption in Dentistry”.

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

All the points have been adressed.