The Influence of Three Different Digital Cement Spacers on the Marginal Gap Adaptation of Zirconia-Reinforced Lithium Silicate Crowns Fabricated by CAD-CAM System

Round 1

Reviewer 1 Report

Abstract:

• Line 19: end of the sentence, change the word "grinned"

Introduction: 

• Line 33: "All-Ceram" change to the full form of the words
• There is no explanation of why Celtra Duo was used as the material of choice instead of more commonly used material such as lithium disilicate.
• Line 44: Reference provided in regards to microleakage and failure is for FPD's, failure rate is generally higher for FPD than single crown so it is best to find a reference specific for single crowns.
• Lines 54 to 56: The description of the study method and comparing it with other study methods are best moved onto discussion section

Materials and Methods

• How was the preparation geometry standardized? who carried out the preparation? How was measurement of convergence and reduction measured? 
• Occlusal reduction was 2.5mm in the study, however the recommendation by the manufacturer is for 1.5mm occlusal reduction... 
• CEREC Omnicam was used, was calibration carried out on the machine prior to use
• Lines 68 to 71: The spacing values used, how were they arrived at by the investigators, highlight the reasons if any.
• Lines 91-93: How were the points for measurement of marginal fit chosen? No explanation given, why 3 points per side and not more or less.  How much spacing was between each point?  Are these points representative of the overall performance of the material?

 

Results:

• Line 102: misspelt the word standard

Author Response

Dear reviewer,

Thank you very much for the review.

we corrected and added according to your comments.

Thank you

Author Response File: Author Response.docx

Reviewer 2 Report

This study is especially important to prevent problems related to dental infections, caries, due to the intervention through restoration work.

Currently these restorations are made using cad-cam technology (computer aided manufacturing) and each spacer is set in the software for each material used.

The paper is original because for the material studied-CELTRA DUA (Sirina Dentsply, USA), there is no recommendation for a certain radial spacer.

In this study, the influence of three radial spacers (60, 90, 120 microns) is considered for the adaptation of the marginal gap by using the cad-cam technique, in order to produce ZLS type crowns (Zirconia Lithium Silicate).

It is shown that the marginal gap for spacers of 90 and 120 microns is clinically acceptable, being around 41.85 microns and the optimal radial spacer for CELTRA DUO crowns is 90 microns.

The working methodology is clearly explained and the results and conclusions are clear and to the point.

I recommend this study for publication.

Author Response

Dear reviewer,

Thank you very much

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Thank you for your reply, my follow up comments are as below

 

Change word grinded to ground to make grammatical sense

Since the models were prepared by a company, please add this detail in the methodology, as well as details of how the teeth prepared, so specify whether it is manually, using a machine etc...?

Add in the limitation that you used non standard occlusal reduction for Celtra Duo

Use reference from other papers on number of observation points per side (possibly same paper that you said used a similar method as yours) otherwise highlight in the limitationt the observation points and why only this many observation points were used.

 

 

 

 

 

 

Author Response

Thank you for the comments

I added and corrected the manuscript

 

Author Response File: Author Response.docx