Retrospective Study of Biohorizons^® Implants Placed by Postgraduate Students at the University of Barcelona

Round 1

Reviewer 1 Report

In this manuscript the authors have done a retrospective study to investigate the success rate of dental implant placed by master students at the University of Barcelona. The study included 192 patients with a total number of 422 implants. The authors have used qualitative and quantitative data with relevant descriptive and comparative statistical analysis. The results reflect on these analyses supporting the authors aims. The authors have done considerable amount of work towards their conclusion and this is obvious throughout the manuscript. However, there are some comments, suggestions, additions, and questions highlighted below that once satisfactory fulfilled I would suggest this manuscript to progress for publication.

 

Major Comments

Line 77: the inclusion criteria relies only on the availability of data in the archive, the authors have not determined any inclusions/exclusion criteria related to the patient, age, medical condition, type of the dental implant, dimensions of dental implant, type of prosthetic treatment all these factors may result in a huge bias. A retrospective study would not be solely based on data availability but on actual patients conditions and treatment options.

The authors refer to failure and success rate, however the authors have not set a criteria of success and a criterial of failure based on the available clinical and radiographical follow up data. Now it is not clear what has failed and what has been successful. Also it seems that the reported 9 failed implants were completely lost but there is not evidence if there has been some implants were sub-clinically failing.

Line 216: “However, none of these factors had a statistically significant relationship with the failures in our study.” The inclusion criteria allowed specific patients to be included based on data availability hence the sample was not a random sample. Looking onto the percentage of patients with these factors it represents a very tiny proportion, hence such a comparison may not be valid. It would be very difficult to conclude that these factors have not significantly affected the failure rate.

A wide selection criteria makes it difficult to draw solid conclusions. The main purpose of retrospective studies is to draw conclusions based on a set of parameters that have to be pre-defined in the study. This is not clear in the study if the authors were comparing success rate based on patients condition, prosthetic treatment and/or implant type.

Furthermore the authors referred to the master student in the introduction, however there is not comparison made to analyse the level of postgraduate training and how does this affect the success rate. Also, if the follow up visits were assessed by the same master students. The authors have no concluding remarks regarding this despite that this is the main aim of the study.

Have the authors done Kappa analysis ? if not Kappa analysis is required 

Minor comments

Title: the title is wordy; the authors may consider a shorter and precise title such as: “Three years retrospective study of Biohorizons implant treatment by master students at University of Barcelona”

Line 26: the concluding statement is not very well written; the authors may consider re-writing the last sentence.

Line 37: Some of the most prevalent (complications) include

Line 39: missing [] brackets for the ref 7

Line 48: repetitive use of on the other hand, the authors may consider using other linking words

Line 55: However, there is limited data on success, survival, and failure percentages (of dental implants placed by) postgraduate students.

Line 56: show that operator’s (skills) influence

Line 75: the authors mention “Once considered suitable”, what determines this suitability ? has there been a criteria for clinical evaluation ?

Line 76: there is no need to mention the initials of the examiners but more important is to describe the qualifications of the examiner and if the authors have calibrated all examiners ?

Line 121: the authors may use males instead of men and females instead of women, this is true for the rest of the manuscript

Results: The authors may firstly describe the demographics of the patients then followed after the description of the implants

Line 126: I guess the authors mean divided by (age) decades and gender

Line 136: the authors may refer to the table for the reader so the reader will have details about type of drug allergies, it is very important for the reader to be informed about these allergies

Figure  1 the legend is not in English, the authors may translate it to English

Table 3 is very crowded is very hard to follow, the authors may simplify it or expand the spaces 

Author Response

Thank you very much for all your comments and suggestions, I attach a word file with the answers 

Author Response File: Author Response.pdf

Reviewer 2 Report

1.) What is the main research question: 

The main research question was to evaluate short- and long-term failure and survival rates and risk factors in a retrospective study after implantation which was performed by students.

2.) The study is interesting and also relevant regarding implantology and dentistry. However, the data presentation needs to be improved, e.g. the author's postulate that they evaluated the data on qualitative and quantitative level. The results part is very difficult to read and would benefit from more structure. Summing up first the qualitative results followed by quantitative results or vice versa can improve the results part and make it more readable. Another suggestion is to put the results including p-values in another table rather than showing the exact data of implant failures (Table 5) which can also be transferred to the supplements.

3.) Concerning originality: the authors already highlight other research on this topic. It is not entirely novel, however benefits from the big cohort group. Implant failure is a hot topic for several years and has already been associated with diseases such as diabetes.

4.) As already mentioned it actually adds more data (high cohort number) and different implantation sites. However, it would have been interesting to show correlations to different situations such as drugs.

5.) The author's conclude that there is high predictability for the success of implant treatments. Since there is only rare and no significant data on correlation to different diseases or habits (e.g. smoking), I am not convinced that the author's can really talk about a high degree of predictability.

6.) The authors listed all the necessary information of the research question.

I hope this comments will help to improve the revision process.

The study is very interesting and informative. However, the data is only listed and does not even include any correlations, just the data summary and easy quantifications. Additionally, I have minor comments which need to be adressed.

 

1.) Line 39: Something happened with the citation here " prosthetic rehabilitation7"

2.) I kindly ask the authors to adjust Table 3, it is difficult to read

Author Response

Thank you very much for all your comments and suggestions, I attach a word file with the answers 

Author Response File: Author Response.pdf

Reviewer 3 Report

               The manuscript I received for review is very extensive, it concerns a retrospective study of 422 implants placed into 192 patients by post-graduate students of the Master of Medicine, Surgery and Oral Implantology from the University of Barcelona. The presented results are very extensive, they relate to the assessment of many aspects of the survival and failure rate, in the short and medium-term, in addition to its relationship with risk factors. I highly appreciate the development of such a large amount of data and the selection of parameters and indicators adopted for the assessment.

               However, despite its undoubted advantages, the manuscript has, in my opinion, quite significant shortcomings:

1. In the article, the authors described 422 implants placed by 3rd year students of the Master of Medicine (according to Line 69), Surgery and Oral Implantology from the University of Barcelona. Moreover, in the first paragraph of the Discussion section, the authors emphasized that the achieved failure rate was 2.13% which is in line with the percentages found in the literature [29,30]. In relation to the above, please rate the level of experience, state how long the students have practiced implantation (Line 71).
2. The presented analyzes were carried out in isolation from the purpose and topic of the work - if the students placed the implants, how did the level of their experience and the mistakes made (and what mistakes) affect the implant failures. The article lacks any methods of assessing students' work and assessing the causes of failure caused by inexperience.
3. The authors emphasize the lack of correlation with the location of the implant, age or gender of the patient. I believe that having full documentation of the cases, one should attempt a broader interpretation of the causes of failures, especially since the implants were placed by students.
4. Are there any significant differences in the student education system at the University of Barcelona compared to other universities? Can the obtained results be treated as a universal reference level for 3rd year students?

 

Minor remarks

1. Line 56: “… influence influences …”
2. L113: SPSS “software” instead of “program”, please complete the information about the software manufacturer and country of origin.
3. The descriptions in Fig. 2 are not in English. It would also be advantageous to do it without the 3D effect.

Author Response

Thank you very much for all your comments and suggestions, I attach a word file with the answers 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you very much for your edits and revisions. It is very evident throughout the manuscript. Overall the authors have successfully answered and covered all comments highlighted in my first review report. I am happy to suggest this manuscript to proceed for publication. There are couple of minor typos the authors may consider before publication, no need to review it again. 

- In the title "Retrospective study Biohorizons®" add of "Retrospective study of Biohorizons®" 

- Line 113: "The implant survival was evaluated after .... ",  remove "were evaluated"

I would like to take this opportunity to congratulate the authors on this work and for their success in producing quality manuscript. 

Many thanks! 

Author Response

Thank you very much for your attentive comments and pertinent modifications. We attach a response letter

Jose Lopez 

Author Response File: Author Response.pdf