Review Reports - Challenging the Resin-Zirconia Interface by Thermal Cycling or Mechanical Load Cycling or Their Combinations

Round 1

Reviewer 1 Report

1. Authors should explain the reason why 50 N is selected for mechanicl load cycling (MLC).

2. Authors should explain the rationale why the flexural strength test is performed in this study.

3. Authors may also describe the correlation betwen the functional monomer, which is contained in resin cement, and shear bond strength measured after aging treatment.

Author Response

Authors should explain the reason why 50 N is selected for mechanical load cycling (MLC).

- Thank you for your suggestion. In this study, the force was chosen to simulate an average of constant load found during mastication. To clarify this, two more references have been added (Lines 212–213).

Authors should explain the rationale why the flexural strength test is performed in this study.

- In this study, mechanical load cycling aging condition was also tested for the resin-bonded zirconia specimens. Therefore, the information regarding mechanical flexural properties of the resins was necessary. In this revision, one sentence has been added in the Materials and Methods section to clarify this (Lines 72–73).

Authors may also describe the correlation between the functional monomer, which is contained in resin cement, and shear bond strength measured after aging treatment.

- Resin bond strength to zirconia may depend on not only the type of functional monomers but also the monomer content. However the exact constituents of the resin materials are not fully disclosed by the manufacturers (Table 1). Therefore, such correlation could not be easily made. Once again, we appreciate all your valuable comments and suggestions.

Reviewer 2 Report

Dear authors;

Congratulations on the research done.

I have no changes to be suggested.

best regards

Author Response

Dear authors; Congratulations on the research done. I have no changes to be suggested. best regards

- We really appreciate your encouraging comment.

Reviewer 3 Report

The article "Challenging the Resin-Zirconia Interface by Thermal Cycling or Mechanical Load Cycling or their combinations" is adequate and could be very interesting for journal readers.

However, there are some points that authors should address in order to have a final more complete paper.

Page 1. Line 16 and 17 I would suggest deleting the first sentence in the abstract.

In order to make the paper easier to follow, I would suggest separating the Results and Discussion sections, as it is more usual.

Regarding statistical analysis, it seems visible that the MLC influences the SBS data more than the TLC for both materials, but this effect is not tested and therefore not a result of the paper. I would recommend adding one more statistical analysis: The groups should be described by two variables TLC (yes/no) and MLC (yes/no), therefore creating a total of 3 independent variables (together with the material). With a 3-way analysis of variance, you'd be able to clarify the % of the variance of SBS attributable to each aging technique. Regarding the presentation of the findings, I would suggest summarizing the ANOVA findings in a sentence or two. The relatively large number of groups compared to make them a bit difficult to read, while the actual point of the results is, in my opinion, fairly simple: "The only statistically significant difference between the two materials is found for the MLC sample. In both samples, aging with both TC and MLC resulted in lower SBS in comparison with samples that were not aged or were aged only with TC. The MLC samples had medium SBS, in the Panavia group, the difference was not significantly different from either group, while in the Rely X it was". I would expect that the 3-way ANOVA would clear this, I expect that the effect of TLC vs. MLC would be different for the two materials, in the sense that TLC would show to affect Panavia more than the Rely X.

Author Response

The article "Challenging the Resin-Zirconia Interface by Thermal Cycling or Mechanical Load Cycling or their combinations" is adequate and could be very interesting for journal readers. However, there are some points that authors should address in order to have a final more complete paper.

- We appreciate your encouraging comment.

Page 1. Line 16 and 17 I would suggest deleting the first sentence in the abstract.

- As you suggested, the first sentence of the Abstract section has been deleted.

In order to make the paper easier to follow, I would suggest separating the Results and Discussion sections, as it is more usual.

- Following your suggestion, the two sections has been separated.

- We appreciate your suggestion regarding the statistical analysis. In our draft, we concluded that the MLC influenced the SBS data more than the TC for both resin materials. As you commented, however, we found that direct evidence supporting this statement was insufficient. Therefore, we performed three-way ANOVA for the SBS data according to your instruction. The three-way ANOVA also did not show any results encouraging the above statement (please see the three-way ANOVA table below). We could not simply conclude again that MLC was more effective in reducing the SBS values than TC. Therefore, we have revised the Conclusions section just based on our findings (please see Lines 232–233). Please give us your further comment regarding our answer, if necessary. Once again, thank you very much for your valuable suggestion.

Source of Variation	Sum of Squares	df	Mean Squares	F	P
Material	128.927	1	128.927	8.152	0.005
TC	255.684	1	255.684	16.167	< 0.001
MLC	1499.904	1	1499.904	94.839	< 0.001
Material × TC	24.048	1	24.048	1.521	0.220
Material × MLC	28.653	1	28.653	1.812	0.180
TC × MLC	17.651	1	17.651	1.116	0.293
Material × TC × MLC	62.563	1	62.563	3.956	0.049