Review Reports

Round 1

Reviewer 1 Report

The idea and development of the set task are generally good. It is necessary to make a detailed analysis of the data from the X-ray phase analysis:

1. Indicate the phase composition of the diffractograms.
2. Determine the degree of crystallinity according to the X-ray data.
3. Present the results obtained in the section Discussion.

In the section Materials and Methods it is necessary to add information about the origin of the control samples. For example, whether these are samples from healthy patients etc.

Author Response

Thank you very much for your comments and suggestions, which no doubt have helped to improve the paper.

We attach the detailed answer to your considerations.

Author Response File: Author Response.pdf

Reviewer 2 Report

Saliva plays an important role in the health of the oral cavity and its composition can be affected by external factors such as diet, alcohol intake, drugs and tobacco use. Enamel dissolution in acidic environments occurs as a consequence of the interaction of hydrogen ions with hydroxyapatite microcrystals. At the same time, the process of remineralization of teeth occurs, which manifests itself in the fact that the enamel is partially demineralized on the surface or inside due to the deposition of calcium, phosphate and other ions present in the oral fluid. The authors of the article have shown how using FTIR-ATR vibrational spectroscopy (and in some cases using X-ray diffraction) it is possible to quantify the concentration of the phosphate group in hydroxyapatite, as well as to determine the characteristics of its crystallinity. It was shown, by using these spectroscopy methods, that the remineralization process is more active in enamel than in the root due to direct contact with saliva. Also, using the methods of infrared spectroscopy, dental samples of 36 patients were evaluated according to the following parameters: crystallinity index (CI), phosphate/amide I ratio and carbonate/phosphate ratio. At the same time, it was noticed that the highest values of CI were found in smoking patients. It can be seen, from the FTIR data, that in both root and crown samples, the intensity of the absorption band corresponding to inorganic phosphate (PO₄³) increases in patients undergoing treatment with psychoactive substances. On the other hand, studies have shown that the intensity of the absorption band of the amide group decreases both with this treatment and with the biological age of the patient.

 

The authors of the article conducted a comprehensive study of the influence of several factors, such as the dental mineralization/remineralization processes on the health of the oral cavity. This work is a complete study and can be published in the journal Minerals.

 

 

Comments for author File: Comments.pdf

Author Response

The authors are grateful for the valuable observations made, which -on account of their precision and conclusiveness- have been included in the final version of the manuscript (abstract and conclusions).

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript by Diez and coworkers purports to be an investigation of the inorganic composition of teeth when exposed to psychoactive substances. The study might have some value from a dental point of view but there are several aspects of this work which need attention.

The authors claim to study the inorganic composition of the teeth but I am afraid that the techniques only give relative information since there are no elemental analyses provided. This work is an FTIR study and the title should be more accurate in stating this. The authors use the term psychoactive, which might be essentially accurate, but does not follow the current usage of that term. I expected a study of the effect on the teeth of LSD and psilocybin use. I don't know the appropriate term for the present study, but it might be pharmacological effects.

Regarding the scientific part, overall it is highly disorganized and very difficult to identify any trends in the data based on the poorly organized prose and ineffective data analysis. Most of the concluding remarks are just common knowledge or common  sense statements and there are no firm statements about the results of the study beyond one sentence on lines 404/405.

There are some further points:

1) "human molars and incisors aged between 21 and 78"? Extracted from people of those ages, surely. It is due to the poor English, I understand, but this kind of inaccuracy at the beginning of a manuscript does not bode well.

2) "The clinical history of each patient was revealed by himself"? Really? Well, the extent of the patients' usage is also not described but obviously this item is not of any scientific accuracy.

3) Similar particle sizes were obtained by mortar and pestle? Really? Without DLS or a similar technique to confirm that, I must reserve judgement on this point.

4) Table 1 has no value. These data must be processed into a graphical form to reveal trends on age and pharmacological effect.

5) Which 8 samples were selected for further analysis and why?

6) Because most of the patients were excluded from the further analysis, data shown in Figs 2,3 for individuals are of little value. 

7) The only discussion point from the pXRD data is that the samples are all similar and a highly speculative assignment of two sharp peaks around 35 degrees in one of the samples. Why does C(33)c give a pattern with reasonable peak shape and resolution and others are broad poorly resolved patterns? 

8) Related to point 5, it seems that the authors have selected an individual patient of each condition to compare. Given genetic and environmental factors, how can a comparison of these individuals' teeth lead to any meaningful clinical conclusions especially in view of the final sentence of the manuscript?

Overall, there might be some useful conclusion to be drawn from the base data but I could not identify any. The data are too spurious having been obtained from too few individuals and not properly presented. 

Author Response

The authors would like to express our gratitude to the Reviewer for his/her comments and especially for his/her comments regarding the correct use of pharmacological terms. In this regard, we admit that the inappropriate designation of pharmacological terms could have led the reader to misinterpret our main study objective. Consequently, we have carefully checked the use of such terms and proceeded to replace -starting from the title of the article- "psychoactive substances" with the term "psychotherapeutic drugs".

The variables collected for the study were age, sex and some remarkable characteristics of the clinical history. These data were collected by the dentists who treated the patients from their medical records, mainly from those related to oral health, when those patients went to the clinic (following the usual protocol in dental offices).

Regarding the specific questions formulated by the Reviewer, a point-by-point response is provided below.

We attach the detailed answer to your considerations

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I have no other remarks to the authors.

Author Response

Thank you for your help.

Reviewer 3 Report

The authors have attempted to revise according to my original comments but I do not find that there has been any substantial improvement.

I would encourage the authors to find a native speaker to make their manuscript understandable in English. There are too many misuses of words for me to detail here. However, they are egregious.

There are still scientific deficiencies (how have the authors assessed what pH the teeth were exposed to? how can the authors know about nicotine intake levels involved?? and there are many others). The authors have suggested that I kindly consider the difficulty involved in obtaining the research materials. I suggest that the authors think more carefully about how they can obtain a suitable source of materials for their research to provide scientifically meaningful conclusions.

There are some other matters arising from the revisions. The authors have persisted with using an abstruse term for the 'psychotherapeutic' substances. It would be better to identify the pharmaceuticals in question (were all patients even receiving the same medication?). There are too few data points to give reasonable correlations and the values of crystallinity provided by the pXRD data are in a range which I doubt has any meaning if precision is considered.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf