Two-Year Longevity of Posterior Zirconia Multi-Unit Fixed Dental Prostheses with Monolithic Occlusal Surface

Round 1

Reviewer 1 Report

Please delete the space between the figures and % all over the text of the manuscript and Table 1. (e.g. incorrect 93.7 % and correct 93.7%).

Author Response

Thank you for appreciating our work. We modified the space according to your suggestions.

Reviewer 2 Report

According to the researchers intention the report is to evaluate the two-year longevity of posterior zirconia multi-unit fixed dental prostheses with monolithic occlusal surface. The aims of the study are clearly stated and the background literature describes sufficient details. The prospective clinical trial included 50 patients. If we would like to evaluate the survival of the zirconium multiunit fixed prostheses, the number of the patients involved is not enough. This work cannot explain the effect of gender unit number material cementation.

Author Response

Thank you for your comments. The authors appreciate the time and effort the referee made for reviewing the manuscript. The authors discussed the comments in detail, yet the authors believe that the manuscript is valuable and thoroughly prepared. The authors believe that the manuscript relevantly contributes to the knowledge about clinical performance of FDPs with monolithic zirconia-based occlusal surfaces. The authors are aware that an effect of sex, unit number, or cementation material cannot be determined by the sample size of the present investigation, however, we never intended to do any comparisons regarding those parameters. The sample size in our investigation is similar to those of other investigations addressing the survival of prosthetic restorations that were published in journals with high impact, such as:

 

Fifteen-year outcome of three-unit fixed dental prostheses made from monolithic lithium disilicate ceramic. Garling A, Sasse M, Becker MEE, Kern M. J Dent. 2019 Oct;89:103178. doi: 10.1016/j.jdent.2019.08.001. Epub 2019 Aug 5.

 

Three-year clinical performance of posterior monolithic zirconia single crowns. Mikeli A, Walter M, Rau S, Raedel M, Raedel M JPD 2021DOI:https://doi.org/10.1016/j.prosdent.2021.03.004

 

Three-year clinical performance of monolithic and partially veneered zirconia ceramic fixed partial dentures. Habibi Y, Dawid MT, Waldecker M, Rammelsberg P, Bömicke W. J Esthet Restor Dent. 2020 Jun;32(4):395-402. doi: 10.1111/jerd.12568. Epub 2020 Jan 30.

 

Antagonist wear of monolithic zirconia crowns after 2 years. Lohbauer U, Reich S. Clin Oral Investig. 2017 May;21(4):1165-1172. doi: 10.1007/s00784-016-1872-6. Epub 2016 Jun 9.

 

Indirect zirconia-reinforced lithium silicate ceramic CAD/CAM restorations: Preliminary clinical results after 12 months. Zimmermann M, Koller C, Mehl A, Hickel R. Quintessence Int. 2017;48(1):19-25. doi: 10.3290/j.qi.a37017.

 

Reviewer 3 Report

This a well-written, brief report on the short term clinical performance of posterior fixed dental prostheses fabricated from zirconia ceramics with monolithic occlusal surface. It provides interesting data on short term use of zirconia prostheses. The employed methods are sound. The data is clearly presented and will be of interest to dental researchers and readers of the journal.  

Author Response

Thank you for your positive comments regarding our manuscript.

Round 2

Reviewer 2 Report

The sample size in the investigation is not enough if we would like to evaluate separately the different factors. The publication cited by the authors contain more specialized investigations e.g. three-unit fixed dental prostheses, zirconia single crowns. The multi-unit fixed dental prostheses in the work is a complex question with different parameters, and in this case 50 patients are not enough data for the evaluating the survival ratio of the different parameters.

Author Response

Thank you for you comments. However, we do not intend to evaluate different factors seperatly (as you seem to assume), but multi-unit FDPs as a restoration type. We cannot agree to your statement that other authors had higher sample sizes (Mikeli n=30, Lohbauer=25) as we had 50 FDPs in total and even n=37 for 3-unit FDPs. Moreover, we only included one restoration per patient, which is -from a statistical view- a real strength of our study in comparison to others. Moreover, we have a statement about our long recruitment process (over 4 years) included in the discussion. Thus, we are not able change the sample size of the investigation.