Root Canal Obturation by Electrochemical Precipitation of Calcium Phosphates
, Victor Palarie 2,†, Maximilian Göltz 3, Marvin Kurzer 3, Manuel Zulla 3, Stefan Rosiwal 3, Marian Willner 4, Andreas Burkovski 5 and Matthias Karl 6,*Round 1
Reviewer 1 Report
- Scale bars should be present on images.
- Please describe XRD data in more details.
Author Response
Response to reviewer 1
- Scale bars should be present on images.
Re.: As recommended by the reviewer, scale bars were introduced in Figure 1 a-d and Figure 3.
- Please describe XRD data in more details.
Re.: All analyses were described in more detail in the revised version of the manuscript (please see response to reviewer 3). For additional text in respect to XRD analyses, see lines 271-274.
Reviewer 2 Report
Manuscript ID: applsci-1622363
Type of manuscript: Article
Title: Root canal obturation by electrochemical precipitation of calcium
phosphates
Authors: Maximilian Koch, Victor Palarie, Maximilian Göltz, Marvin Kurzer,
Manuel Zulla, Stefan Rosiwal, Marian Willner, Marian Willner, Matthias Karl *
A combination of calcium phosphate and maleic acid was used as precursor solution while Ion Chromatography Mass Spectrometry (IC-MS), Raman spectroscopy (RAMAN), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), dye penetration and micro-computed tomography (μCT) were applied for characterizing the precipitate. It was possible to achieve a BDD-mediated precipitation of brushite in a clinically applicable timeframe. Results showed tight sealing of the canal system based on brushite could not be achieved.
Major suggestion: The authors performed many measurements asystematic and did not show the main findings and analyzed the results well, suggesting to reveal relevant results and discuss why. The focus of this study should be rationalized, others may be provided in supplements to prevent complex inferred expressions
Minor suggestions:
2.1. Chemicals- lines 88-93: I can't understand this expression of CaCO3, 1.78 g, 17.8 mmol, 100g/mole=Mw, 0.445M?, C4H4O, and ?? about preparation and how to make sure the CO2 generation stopped, please clarify.
Lines 96-99: All solution pH values before and after the reaction are recommended.
2.2. Can the authors combine figures 1-3 in Materials and methods and provide relative scales
Lines 133-135: Even caries-free human teeth require IRB approval and are recommended.
- Results
Figure 4- Is there any difference between the BDD of a to d about the electrode initiate precipitation
Figure 5- please added the repeat testing n values and with the deviation of precipitate mass just like the expression of maleic acid concentration.
Figure 6- Lines 268-269: Can the authors offer different potential 6, 10, 16 for examples to determine that the crystal morphology is not different? Different pH values would generally generate different calcium phosphate phases with different morphologies.
Figure 7- Can the authors clarify the difference by Raman spectroscopy, wavenumber of 500-1300 is suggested.
Figure 8- again, The authors performed many measurements asystematic and did not show the main findings and analyzed the results well, suggesting to reveal relevant results and discuss why.
It is recommended to insert conclusions.
Author Response
Response to reviewer 2
Major suggestion: The authors performed many measurements asystematic and did not show the main findings and analyzed the results well, suggesting to reveal relevant results and discuss why. The focus of this study should be rationalized, others may be provided in supplements to prevent complex inferred expressions.
Re.: Based on the valuable hints of reviewer 2, we have changed the order of the experiments presented and added more thorough explanations for the rationale of the different analyses and a more detailed description of results (see l. 225-226, 258-263, 271-274, 283-287).
Minor suggestions:
Chemicals- lines 88-93: I can't understand this expression of CaCO3, 1.78 g, 17.8 mmol, 100g/mole=Mw, 0.445M?, C4H4O, and ?? about preparation and how to make sure the CO2 generation stopped, please clarify.
and
Lines 96-99: All solution pH values before and after the reaction are recommended.
Re.: The description of the preparation of the precursor solution was completely reworded (l. 88-95). We hope that the procedure is clear now.
Lines 133-135: Even caries-free human teeth require IRB approval and are recommended.
Re.: The teeth used in this study were extracted during regular treatments of various patients and stored for research and educational purposes. As per the guidelines at Saarland University dental school, ethics committee approval was not required here. This has been explicitly added under “Institutional Review Board Statement”
Figure 4- Is there any difference between the BDD of a to d about the electrode initiate precipitation.
Re.: There is only a constructional difference between the electrodes. The glued electrode was manufactured to safe space in the root canal and to ease the application. Wires and parameters were the same. Information on identical precipitation is given in l. 108-109.
Figure 5- please added the repeat testing n values and with the deviation of precipitate mass just like the expression of maleic acid concentration.
Re: Figure 5 was changed as recommended.
Figure 6- Lines 268-269: Can the authors offer different potential 6, 10, 16 for examples to determine that the crystal morphology is not different? Different pH values would generally generate different calcium phosphate phases with different morphologies.
Re.: RAMAN spectroscopy was used as scanning option to answer this question (Figure 8 of revised manuscript, lines 290-297). There was no evidence for other calcium phosphate species.
Figure 7- Can the authors clarify the difference by Raman spectroscopy, wavenumber of 500-1300 is suggested.
Re.: Differences in powder grain size sometimes impede a HQ RAMAN measurement. First measurements indicated a difference in precipitation grain size depending on the alternation in potentials. Repetition of the measurement showed no evidence for this connection. Differences in spectra were identified as high background.
Figure 8- again, The authors performed many measurements asystematic and did not show the main findings and analyzed the results well, suggesting to reveal relevant results and discuss why.
Re.: As described above, we have changed the order of the experiments presented and added more thorough explanations for the rationale of the different analyses and a more detailed description of results (see l. 225-226, 258-263, 271-274, 283-287).
It is recommended to insert conclusions.
Re.: Added as suggested (l. 400-407).
Reviewer 3 Report
This paper is undoubtedly useful and interesting, but in this form it cannot be recommended for publication yet and some points need to be clarified more clearly.
- the purposes of use, and in particular the results obtained with the help of Raman spectroscopy, need a more detailed analysis. In practice, a very interesting series of spectra is presented in the work, but no physical conclusions are drawn from them. Moreover, even there is a feeling, but was it necessary to go to the Raman spectrometer at all? A summary table with interpretation and conclusions on the main features of the spectra would be extremely useful
- The outcome of HA also depends on their resistance to aging, including radiation. See:
Bystrova, A.; Dekhtyar, Y.D.; Popov, A.; Coutinho, J.; Bystrov, V. Modified hydroxyapatite structure and properties: Modeling and synchrotron data analysis of modified hydroxyapatite structure. Ferroelectrics 2015, 475, 135–147.
Hübner, W.; Blume, A.; Pushnjakova, R.; Dekhtyar, Y.; Hein, H.-J. The influence of X-ray radiation on the mineral/organic matrix interaction of bone tissue: An FT-IR microscopic investigation. Int. J. Artif. Organs 2005, 28, 66–73.
Considering that various radiation treatments have been applied even in this work, radiation issues and radiation aging should be mentioned at least briefly.
- Please check reference 21. It seems that there is no page numbers.
Author Response
Response to reviewer 3
This paper is undoubtedly useful and interesting, but in this form it cannot be recommended for publication yet and some points need to be clarified more clearly.
- the purposes of use, and in particular the results obtained with the help of Raman spectroscopy, need a more detailed analysis. In practice, a very interesting series of spectra is presented in the work, but no physical conclusions are drawn from them. Moreover, even there is a feeling, but was it necessary to go to the Raman spectrometer at all? A summary table with interpretation and conclusions on the main features of the spectra would be extremely useful
Re.: Thank you for this valuable hint. As described in response to reviewer 2, we have changed the order of the experiments presented and added more thorough explanations for the rationale of the different analyses and a more detailed description of results (see l. 225-226, 258-263, 271-274, 283-287). RAMAN spectroscopy was used for a quick scanning option, which would indicate the formation of other calcium phosphate phases in the serial tests at different potentials. There was no evidence for other calcium phosphate species.
- The outcome of HA also depends on their resistance to aging, including radiation. See:
Bystrova, A.; Dekhtyar, Y.D.; Popov, A.; Coutinho, J.; Bystrov, V. Modified hydroxyapatite structure and properties: Modeling and synchrotron data analysis of modified hydroxyapatite structure. Ferroelectrics 2015, 475, 135–147.
Hübner, W.; Blume, A.; Pushnjakova, R.; Dekhtyar, Y.; Hein, H.-J. The influence of X-ray radiation on the mineral/organic matrix interaction of bone tissue: An FT-IR microscopic investigation. Int. J. Artif. Organs 2005, 28, 66–73.
Considering that various radiation treatments have been applied even in this work, radiation issues and radiation aging should be mentioned at least briefly.
Re.: HA was not used nor produced in this study as indicated via XRD, EDX and RAMAN.
- Please check reference 21. It seems that there is no page numbers.
Re.: Added.
Round 2
Reviewer 2 Report
The authors have had great success in revising the question, so this is acceptable.
Reviewer 3 Report
The article is significantly improved, all comments and questions received due response, the article can be recommended for publication.
