The Effects of Activated Carbon Toothpastes on Orthodontic Elastomeric Chains—An In Vitro Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In the paper titled “The effect of activated carbon toothpastes on orthodontic elastomeric chains - an in vitro study” evaluated the influence of activated charcoal toothpaste on the orthodontic elastomeric chains.

 

Abstract:

- Clinical significance can be improved, I recommend the authors to rewrite.

 

Introduction:

- What are the differences between conventional and activated charcoal toothpastes? It would be beneficial to include more information.

- “However, in orthodontic patients particularly, the use of toothpaste with activated carbon might increase the decay of EC tensile strength, thereby compromising orthodontic treatment.“ Reference this sentence.

- The justification for expecting a reduction in the force provided by elastomeric chains when using activated charcoal toothpaste requires further clarification in this section.

- Rewrite the objective clearly and succinctly.

- What are the hypotheses to be tested in the study?

 

Materials and Methods:

- I suggest that the authors develop a diagram illustrating the acrylic plate used for stretching the elastic chains used in the experimen, in figure 1.

 

Discussion

- In the first two paragraphs of the discussion, a general and detailed analysis of the findings must be carried out, in addition to reporting whether the null hypotheses were accepted or rejected.

- This sentence should be removed: “None of the investigations in the literature explored the effect of external elements on the resistance to rupture of ECs, however, so we are unable to make meaningful comparisons.” It seems to me that the authors try to justify why they cannot discuss, instead of reporting what is actually available in the literature and thus supporting their findings.

- The discussion could be improved, in addition to the analysis of the results, this section should be informative, considering that it is based on a limited amount of evidence.

- How can their findings benefit clinical research in the long term?

- What are the limitations of the study?

 

 

Conclusion

- Rewrite the conclusion, highlighting the main results obtained in the study in a concise manner.

Author Response

Reply to reviewers’ reports

Reviewer 1

Thank you for agreeing to review our manuscript and for your suggestions.

Abstract

Comment Clinical significance can be improved. I recommend the authors to rewrite.

Reply The following paragraph in the manuscript indicates the clinical significance of the study

One consistent finding in our study was that Ortho Classic^® EC showed significantly greater

Introduction

Comment What are the differences between conventional and activated charcoal toothpastes? It would be beneficial to include more information.

Reply The introduction has been updated with more information about toothpastes as follows

Numerous types of toothpaste have been developed and introduced onto the market. Nearly all contemporary toothpaste includes essential elements such as thickening agents, flavour, surfactants, water and specific agents that benefit consumer needs. These benefits include whitening teeth, improving gingival care, reducing tooth sensitivity, freshening breath and increasing enamel resistance to the risk of caries [8,9].

There has been an increase in both the demand for and supply of whitening toothpaste containing activated carbon [8,9]. This abrasive component removes and prevents the formation of external enamel pigments but can be excessively abrasive due to the particles' size [10,11]. Throughout fixed orthodontic treatment, tooth enamel is frequently more susceptible to stains, leading patients to use whitening instead of conventional toothpaste to regain tooth brightness. Dental plaque and discolouration are removed from teeth through a three-stage scheme consisting of toothbrush bristles, enamel tooth surface and the activated carbon abrasive particles in between [12,13]. The mechanical action of brushing bonded teeth wearing auxiliary EC might increase their tensile strength decay, compromising orthodontic treatment [14]. Other local considerations might exacerbate the impact of toothpaste, such as toothbrush bristles' number and shape, frequency, and brushing technique [15,16]. Numerous investigations confirmed that active carbon toothpaste is highly absorbent and can exchange ions across nanopores, adhere to enamel and remove stains by absorbing pigments from the tooth enamel surface [15,16,17,18].   A search of the published literature found only two studies exploring the impact of activated carbon on EC [5,14].  Behnaz et al. [14] concluded that toothpaste with whitening agents significantly reduces EC tensile strength compared to non-whitening toothpaste.  However, their investigators used only one type of EC (3M Uniteck^®). In another study, Pithon et al. [5]. observed a similar degrading effect of two of the most widely used whitening mouthwashes (Plux and Listerine) on an EC manufactured by Morelli (Sorocaba, Brazil) commercially available whitening mouthwashes. Furthermore, according to our search, none of the studies investigated the impact of activated carbon toothpaste on EC rupture point and colour stability. 

 

Comment What are the hypotheses tested in the study?

Reply The hopetheses tested has been added as follows;

Within this context, the following null hypotheses were tested

• The presence or absence of activated carbon agents in toothpaste has a similar effect on EC tensile strength degradation overtime
• The presence or absence of activated carbon agents in toothpaste has a similar effect on the EC rupture point over time
• The presence or absence of activated carbon agents in toothpaste has a similar effect on the EC colour stability

Comment “However, in orthodontic patients particularly, the use of toothpaste with activated carbon might increase the decay of EC tensile strength, thereby compromising orthodontic treatment.“ Reference this sentence.

Reply The introduction has been substantially updated and cited accordingly

Comment - The justification for expecting a reduction in the force provided by elastomeric chains when using activated charcoal toothpaste requires further clarification in this section.

Reply The justification has been added to the updated version of the manuscript with citations (the above paragraphs

 

Materials and Methods

Comment I suggest that the authors develop a diagram illustrating the acrylic plates used for stretching the elastic chains used in the experiment in Figure 1

Reply We believe that Figure 1 illustrates clearly the stretched elastic chains between the mounted pins on the acrylic plate. 

 

Discussion

Comment In the first two paragraphs of the discussion, a general and detailed analysis of the findings must be carried out. In addition to reporting the null hypothesis, accepted or rejected

Reply There are various guidelines for writing the discussion section. The guideline that I use to introduce the investigation is in the first paragraph. The second paragraph critiques the methodology used, and the third paragraph introduces the results and then compares them with the available findings from other studies. The acceptance/rejection of each null hypothesis has been added next to the result investigated.

 

Comment - This sentence should be removed: “None of the investigations in the literature explored the effect of external elements on the resistance to rupture of ECs, however, so we are unable to make meaningful comparisons.” It seems to me that the authors try to justify why they cannot discuss, instead of reporting what is actually available in the literature and thus supporting their findings.

Reply The sentence has been removed

Comment on how the findings can benefit clinical research in the long term.

Reply The manuscript has two recommendations in the discussion section;

• Further, in vivo studies are recommended to gain a complete understanding of the elastomeric behaviour of more brands of ECs in the oral cavity
• Toothpastes containing activated carbon are relatively new in the market, and few studies have been carried out to investigate their effect on dental materials. Therefore, further research is required. In particular, it would be interesting to evaluate the effect of other whitening toothpastes available in the market on the intrinsic characteristics of the available EC brands.
• Throughout this investigation, the ECs were always stretched to a fixed distance between the pins installed on the acrylic plates without simulating the tooth movement that occurs during oral function. This might have affected the experimental outcome¹⁶ and therefore it is recommended that a randomized clinical trial be undertaken to further explore EC behaviour in a clinical setting.

 

Comment What are the limitations of the study?

Reply The second paragraph in the discussion highlights the limitation of the study being in vitro and also because the EC were fixed and stable without mimicking their movement during oral function as follows;

The in vitro design of the present investigation offered the possibility of evaluating one covariate at a time (in this case, activated carbon) and avoiding the influence of other components present in the oral cavity, such as pigmentation caused by food and drink [20,21]. However, despite the previously reported advantages, an in vitro study design falls short of simulating an oral environment that includes enzymes, pH variation, natural microflora and temperature fluctuation. Therefore, it is imperative to exercise caution when generalizing the outcomes of such investigations to clinical circumstances [20,21].

Throughout this investigation, the ECs were always stretched to a fixed distance between the pins installed on the acrylic plates without simulating the tooth movement that occurs during oral function. This might have affected the experimental outcome  Therefore it is recommended that a randomized clinical trial be undertaken to further explore EC behaviour in a clinical setting.

 

Conclusion

Comment Rewrite the conclusions, highlight the main results obtained in the study in a concise manner

Reply Please specify what you did not agree with in the conclusion- The included conclusion answers the aims and null hypothesis of the investigation clearly and in a concise way as follows  ·        There is a significant tensile strength, rupture point and colour discrepancy between the three EC brands tested both before and after their exposure to any toothpaste;·       The material composition of each brand of EC contributes to their strength decay, resistance to rupture and colour change over time;·      The percentage of activated carbon in a toothpaste may be responsible for the variable effects on each brand of EC. 

 

Reviewer 2 Report

Comments and Suggestions for Authors

The use of charcoal toothpaste for whitening reasons is a subject of several studies related to dentistry, in terms of whitening effectiveness, and enamel induced changes. In this work, the authors are dealing with the effects of charcoal-containing toothpastes on materials used for orthodontics.

There is no question regarding the relevance of the proposed paper with the aims and scope of the Journal, and the significance of the study itself. Furthermore, the manuscript is well written, in terms of language use, it’s easy to follow and the results are accompanied by a well supported discussion. Nevertheless, some points should be taken into consideration before the proposed manuscript should be considered for publication.

 

Main issues

1.       Please, expand the introduction. It I very short, and this is also screened by the number of used citations (11). For example, where are ECs used (the “orthodontics” is very general for potential readers that are connected to the field), are there any relevant studies with their in vivo or in vitro ageing, what are they affected from etc. What is the effectiveness of activated carbon toothpastes for whiteness, what are the problems they induce to the mouth cavity etc.

2.       In conclusion, it is stated that “The material composition of each brand of EC contributes to their strength decay, resistance to rupture and colour change over time”. Could the authors give some details regarding that? Maybe from the ECs’ technical sheets, in the materials and methods section?

 

Manuscript format and language issues

1.       Please, be careful, the manuscript’s title is not correct in the submission system.

2.       At some point, the authors will need to use the Journal’s manuscript template.

3.       Abstract. Please, check the Journal’s instructions, regarding no use of headings in it and a total of 200 words.

4.       Materials and Methods. Regarding the “xxxxxxxxxxxxxxxxxxxxxxxx”, is this a draft and not the final form of the manuscript for submission?

5.       I believe that the “Sample Size” paragraph should be placed after the Sample preparation one.

Author Response

Thank you for agreeing to review our manuscript and for your suggestions.

Comment : Please expand the introduction. It I very short, and this is also screened by the number of used citations (11). For example, where are ECs used (the “orthodontics” is very general for potential readers that are connected to the field), are there any relevant studies with their in vivo or in vitro ageing, what are they affected from etc. What is the effectiveness of activated carbon toothpastes for whiteness, what are the problems they induce to the mouth cavity etc

Reply The introduction has been updated, taking into consideration yours and the first reviewer suggestions 

Comment In conclusion, it is stated that “The material composition of each brand of EC contributes to their strength decay, resistance to rupture and colour change over time”. Could the authors give some details regarding that? Maybe from the ECs’ technical sheets, in the materials and methods section?

Reply The exact and specific details of the composition of the EC vary between companies and not shared due to commercial competition.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear author, I have no more questions. Thank you.