Fatigue Design of Dental Implant Assemblies: A Nominal Stress Approach

Round 1

Reviewer 1 Report

See attached PDF file

Comments for author File: Comments.pdf

Author Response

Please, see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

The work contains data from the fatigue experiment that may be worth publishing. It contains some minor errors, including no description of the friction experiment as a separate section.

However, it contains one very serious shortcoming which, in my opinion, disqualifies work if it is not reliably completed.

Please show your results of FEA - illustration from Ansys where are located the contact forces and how is directed during loading.

It should be shown Fa and Ft for each preload and clearly documented on the 3D models where are the contact zones?

In Ansys there is in contact result the contact state: "open" "near" and "closed". How does it work in a simplified "half" symmetry model during bending?

How the preload was applied? Thermal or mechanical? Clearly show the preload zone with the measure in mm.

Fig. 2 and 3 can be joined. Fig 1 is unnecessary.

Line 85 Titanium

titanium

Line 87 ..Co ...

?

in 2.1 the number of implants per each experiment ?

Instron force head (gauge) parameters ?

Line 165 -168

Torque belongs to line 120

Line 138 Values of friction coefficients measured in the pin-on-disk test show,

Why experiment is placed in section 2.2 FEA ? Please make alone the section. The experiment should be clearly presented. How the coefficients were measured? The obtained values are smaller than known form other works. Why it is not discussed?

Author Response

Please, see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This is a manuscript on the fatigue design of dental implants and authors attempted to propose a new method to evaluate and predict fatigue life combining ISO 14801 and FEA. It seemed that as they used only one implant design in the study, it would be difficult to generalize the efficacy of the method for other implant designs. It would not have a big impact for the clinician (as they mentioned in the manuscript) because this study did not focus on the bone-implant interface at all. However, it might help deepen the understanding of the mechanical properties for engineers who are working on the manufacturing processes including the implant design.

Authors should add more detailed explanation on each figures.

It was hard to catch up by going back and forth between Figures and description in Methods and Results sections.

Followings are minor issues.

Line 15

Please spell out FEA, though it is obvious.

Line 113-114

Add the information of the supplier.

Line 130

Please add explanation how it was verified that screw response was almost identical using cylindrical threads.

Figure 8

Failure mode was described in the manuscript, but captions for Figure 8 describing at which part failure occurred should be added.

Figure 11

It is unclear where section A and section B are.

Figure 14

More explanation should be added for Figure 14.

Author Response

Please, see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Materials:

1) The test method described in ISO 14801 standard is known. Figure 4 need not be presented.

2) The method of tribological examination is described in section 2.2. I propose to create subchapter 2.3, and more widely describe the method of friction testing (load, friction speed, friction radius, etc.).

3) Table 2 presents the results of the research. I suggest moving the table to chapter 3.

Results and discussion

1) In figure 10 the value of the coefficient of determination can be given.

2) Check that all graphs and tables contain the correct units. Check the decimal separator. Check the space between the values and the unit on the charts.

Results and discussion/Conclusions

1) Fractographic analysis is cursory. Shows SEM images of only one case. Perhaps the authors should consider supplementing the proposed method of screw durability testing with fractographic analysis.

To summarize, the manuscript will be ready for publication after a minor revision.

Author Response

Please, see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

" The problems in which the body possesses an axis of symmetry and the boundary conditions and other parameters of the problem are symmetric with respect to this axis are called as axisymmetric problems. The cylindrical coordinate system is found to be convenient for analyzing such problems."   How the contact problem was defined for axisymetric problem with oblique load? i can find how it is possible ?   https://support.ansys.com/staticassets/ANSYS/staticassets/resourcelibrary/confpaper/2006-Int-ANSYS-Conf-47.pdf http://www.ce.memphis.edu/7117/notes/presentations/chapter_09.pdf https://core.ac.uk/download/pdf/55731989.pdf  

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

All issues I raised have been addressed appropriately.

Author Response

Thank you for your review.

Round 3

Reviewer 2 Report

Dear Authors

Thank you on behalf of the Readers for the explanations.

I forgot to add to discuss the issue of omitting stress from torque in the half model.

 If you can, please add some opinion on this topic. The thing is that in the half-model with artificial preload there is no screw twist around the axis. The impact of this on the distribution of contact forces, which by their nature are not symmetrical in relation to the load plane, is unknown in this model and can be studied in the future

Best regards

Author Response

Please see the attachment

Author Response File: Author Response.pdf