Intraoral Scanning Versus Conventional Methods for Obtaining Full-Arch Implant-Supported Prostheses: A Systematic Review with Meta-Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This review focus is the intraoral scanning for producing full-arch implant supported prostheses comparing with conventional Methods. In the results of the study the authors found that the scanning method to develop full-arch fixed prostheses was similar to the conventional impression technique considering technical and biological complications and MBL. They also found that the procedure time for the group of rehabilitations made by the intraoral scanning method was faster. Nevertheless, conventional method achieved fewer retakes than digital.

It would be expected no complications or MBL and also a faster procedure because intraoral scanning allows the professional to visualize and adjust the impressions but also provides the flexibility to repeat them within the same session if necessary. Considering these facts the only relevant information are the number of retakes when using the conventional method.

Digital technology offers several advantages over conventional techniques. They do not require the use of a tray or impression material so intraoral scanning is a simpler and safer technique for taking impressions specially in maxillectomy patients.

After reviewing the manuscript it seems that the contents do not significantly contribute to the current literature

To improve your manuscript, please consider the following issues to be adressed either in Introduction and/or in the Discussion:

1. the learning curve, dentists and technicians need to be trained (it is only mentioned briefly in the discussion)

2. the scanner limitation- captures only mucostatic impressions

3. the manufacturing process: possibility of using new materials with high resistance and better aesthetic results.

4. complex cases where patients have severely limited mouth opening (also briefly mentioned)

5. the hibrid technique (conventional and digital)

You can review the following references to obtain more information in each of the topics above.

Ye, H., Wang, Z., Sun, Y., & Zhou, Y.(2020). Fully digital workflow for the design and manufacture of prostheses for maxillectomy defects. The Journal of Prosthetic Dentistry, 126(2), 257-261. https://doi.org/10.1016/j.prosdent.2020.05.026

Takaichi, A., Fueki, K., Murakami, N., Ueno, T., Inamochi, Y., Wada, J., Arai, Y., & Wakabayashi, N. (2022). A systematic review of digital removable partial dentures. Part II: CAD/CAM framework, artificial teeth, and denture base. Journal Prosthodont Research, 66(1), 53-67. https://doi.org/10.2186/jpr.JPR_D_20_00117

 

Suganna, M., Kausher, H., Tarek, Ahmed, S., T., Alharbi, H., S., Alsubaie, B., F., Haleem, S., Ali, B., M., R. (2022). Contemporary evidence of cad-cam in dentistry: a systematic review. Cureus 14(11), e31687. https://doi.org/10.7759/cureus.31687

Other concerns to revise are described below.

✓ The authors should clarify inclusions and exclusions criteria, namely the time frame

✓ The number of articles used for meta-analysis (consider to exclude this part)

✓ The Conclusions do not support the Abstract ( say differente things)

Further studies on this topic could be an innovative issue by adding new information helpful for the dental community However, this study, in my view does not, in its current form, satisfy a high scientific requirement.

 

Author Response

REVIEWER 1

 

This review focus is the intraoral scanning for producing full-arch implant supported prostheses comparing with conventional Methods. In the results of the study the authors found that the scanning method to develop full-arch fixed prostheses was similar to the conventional impression technique considering technical and biological complications and MBL. They also found that the procedure time for the group of rehabilitations made by the intraoral scanning method was faster. Nevertheless, conventional method achieved fewer retakes than digital. It would be expected no complications or MBL and also a faster procedure because intraoral scanning allows the professional to visualize and adjust the impressions but also provides the flexibility to repeat them within the same session if necessary. Considering these facts the only relevant information are the number of retakes when using the conventional method. Digital technology offers several advantages over conventional techniques. They do not require the use of a tray or impression material so intraoral scanning is a simpler and safer technique for taking impressions specially in maxillectomy patients. After reviewing the manuscript it seems that the contents do not significantly contribute to the current literature

 

R.: We would like to thank the reviewer for evaluating our manuscript. We have made substantial changes to it, rewriting and reorganizing it. We strongly believe that we were able to fully address the points raised and, therefore, have significantly improved the overall quality of the manuscript. All requested modifications are highlighted in green.

            It is essential to emphasize that a clinical execution protocol should be grounded in the best scientific evidence. Given the variety of results in the literature on this subject, conducting a systematic review with meta-analysis is necessary to establish a consensus on the appropriate methods. Additionally, these findings regarding the increased number of repetitions required for the digital scanning method highlight the differences in the learning curves associated with implementing these techniques, as discussed more thoroughly in the revised text.

            While the reviewer points out that certain evidence is based on clinical perception, the quantitative data remains significant as it provides valuable insights derived from clinical practice. The reviewer also mentioned the potential use of this method in patients undergoing maxillectomy, which we acknowledge as an important and effective application. Although this review primarily focused on evaluating edentulous patients in line with the PICO question, we have incorporated additional information into the discussion based on the reviewer’s suggestion.

            We understand the reviewer's concern about the marginal bone loss variable's importance for the proposed question in this systematic review. However, the variable was studied in depth by the included studies; it was a proposition included in the methodology of the primary studies, for example (Elawady et al. 2024):

"The results of this randomized controlled trial revealed a non-statistically significant difference in the MBL of maxillary screw-retained implant prostheses fabricated from full-arch digital implant impressions compared to those fabricated from conventional implant impression, which agrees with earlier studies..."

 

To improve your manuscript, please consider the following issues to be adressed either in Introduction and/or in the Discussion:

 

1. the learning curve, dentists and technicians need to be trained (it is only mentioned briefly in the discussion).

R.: During the discussion, we emphasized additional factors that could affect the observed data, such as the learning curve associated with the technique.

 

2. the scanner limitation- captures only mucostatic impressions

R.: This and other limitations of using the digital impression were better addressed throughout the article's discussion.

 

3. the manufacturing process: possibility of using new materials with high resistance and better aesthetic results.

 

R.: The study aimed to investigate the divergences and consequences of the impression method. Following your suggestion, we conducted a detailed analysis of the occlusal materials used in the included studies. We also highlighted the promising potential of new materials. It is important to note that in the results section, there is a list of the complications observed with new materials, such as zirconia, including cases of decementation and fracture.

 

4. complex cases where patients have severely limited mouth opening (also briefly mentioned)

R.: Due to the specific objectives of the systematic investigation and the final sample included in the study, it was not feasible to examine the impact of the methodology on patients with limited mouth opening. However, given its clinical significance, this issue is addressed in the discussion of the findings.

 

5. the hibrid technique (conventional and digital)

 

R.: We appreciate the suggestions and improvements in the discussion section of this study, which was performed considering that the hybrid flow also represents a practical and safe indication in Dentistry.

 

You can review the following references to obtain more information in each of the topics above.

Ye, H., Wang, Z., Sun, Y., & Zhou, Y.(2020). Fully digital workflow for the design and manufacture of prostheses for maxillectomy defects. The Journal of Prosthetic Dentistry, 126(2), 257-261. https://doi.org/10.1016/j.prosdent.2020.05.026

Takaichi, A., Fueki, K., Murakami, N., Ueno, T., Inamochi, Y., Wada, J., Arai, Y., & Wakabayashi, N. (2022). A systematic review of digital removable partial dentures. Part II: CAD/CAM framework, artificial teeth, and denture base. Journal Prosthodont Research, 66(1), 53-67. https://doi.org/10.2186/jpr.JPR_D_20_00117

 Suganna, M., Kausher, H., Tarek, Ahmed, S., T., Alharbi, H., S., Alsubaie, B., F., Haleem, S., Ali, B., M., R. (2022). Contemporary evidence of cad-cam in dentistry: a systematic review. Cureus 14(11), e31687. https://doi.org/10.7759/cureus.31687

 

R.: We greatly appreciate your contribution, and the references have been incorporated into the discussion in the article

 

 

 

 

Other concerns to revise are described below.

✓ The authors should clarify inclusions and exclusions criteria, namely the time frame.

R.: The paragraph containing inclusion and exclusion criteria was better formulated so that these could be better clarified.

“The selected studies accomplished the following inclusion criteria: 1) conducted in English; 2) clinical studies with a sample size greater than 5 participants that compared implant-supported prostheses using digital methods to conventional methods in edentulous patients. Studies that included only the digital group were also considered if they aligned with the proposed outcomes. The participants in each study were adults who received full-arch implant-supported fixed prostheses or overdentures. Studies related to in vitro methodologies, uncontrolled clinical case series, studies with incomplete data that did not allow for the necessary information to be collected, and studies involving patients with complications from extensive surgical resections were excluded.”

✓ The number of articles used for meta-analysis (consider to exclude this part)

R.: The variables examined in the meta-analysis align closely with the objectives of this review. This is crucial as it enables us to assess the viability of the evaluated methods without compromising any of the analyzed variables. Previous systematic reviews conducted by our group have also utilized a limited number of studies, and according to the Cochrane Collaboration, a minimum of two studies is sufficient to perform a meta-analysis, reaffirming the credibility of our research. Furthermore, we incorporated a GRADE analysis to evaluate the certainty of evidence for each outcome. This enhancement allows for a more comprehensive data analysis and facilitates extrapolations for future studies in this field.

 

References:

1. Jonathan J Deeks, Julian PT Higgins, Douglas G Altman, Joanne E McKenzie and Areti Angeliki Veroniki; on behalf of the Cochrane Statistical Methods Group. Chapter 10: Analysing data and undertaking meta-analyses. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA, editores. Cochrane Handbook for Systematic Reviews of Interventions versão 6.5 (atualizado em agosto de 2024). Cochrane, 2024. Disponível em: https://training.cochrane.org/handbook.
2. Sugio CYC, Garcia AAMN, Kitamoto KAA, Santiago Júnior JF, Soares S, Porto VC, Urban VM, Ferrari PC, Fernandes MH, Neppelenbroek KH. Mucoadhesive delivery systems for oral candidiasis treatment: A systematic review and meta-analysis. Oral Dis. 2024 Sep;30(6):3771-3787. doi: 10.1111/odi.14928. Epub 2024 Mar 24. PMID: 38523365.
3. Chappuis-Chocano AP, Venante HS, Costa RMBD, Pordeus MD, Marcillo-Toala OO, Santiago Junior JF, Porto VC. A systematic review and meta-analysis of the clinical performance of implant-supported overdentures retained by CAD-CAM bars. J Appl Oral Sci. 2023 Aug 25;31:e20230054. doi: 10.1590/1678-7757-2023-0054. PMID: 37646715; PMCID: PMC10501751.

 

✓ The Conclusions do not support the Abstract ( say differente things)

 

R.: To enhance clarity, the text was revised to better present the analyzed information in this study and its implications for the dental community.

“It is concluded that the survival rates of full-arch fixed prostheses fabricated using intraoral scanning are comparable to those achieved with traditional impression techniques, providing a reliable option for patients. However, further clinical studies are necessary due to the variability in clinical protocols.”

 

Further studies on this topic could be an innovative issue by adding new information helpful for the dental community. However, this study, in my view does not, in its current form, satisfy a high scientific requirement.

R.:  We have reformulated all highlighted text to meet the highest standards of the dental scientific community. It is worth noting that, as of 2024, no systematic review with meta-analysis evaluating clinical data from edentulous patients has been identified in the literature. Recently, an overview of systematic reviews published in the Journal of Prosthetic Dentistry (Kaitatzidou, 2024) included additional information and data on oral rehabilitations involving partial prostheses.

 

None of the systematic reviews published on edentulous patients included meta-analyses. The findings from these reviews underscore the need for new studies and serve as a clear call to action for further research.

 

Gaikwad et al. 2022 (overview), which reinforce:

"However, the accuracy of full-arch digital impressions involving multiple implants is not satisfactory and needs significant improvements." "However, full-arch digital impressions involving multiple implants are not satisfactorily accurate and need significant improvements."

 

The systematic review by Carneiro et al. 2021 considered only in vitro studies (edentulous patients) in its sample: "Eight in vitro studies that met the eligibility criteria were evaluated."

 

Papaspyridakos et al. 2014 “For completely edentulous patients, most in vitro studies and all three clinical studies demonstrated better accuracy with the splinted vs the nonsplinted technique…”

 

References:

1. Kaitatzidou A, Chalazoniti A, Faggion CM Jr, Bakopoulou A, Barbosa-Liz DM, Giannakopoulos NN. Digital scans versus conventional impressions in fixed prosthodontics: An overview of systematic reviews. J Prosthet Dent. 2024 Dec 2:S0022-3913(24)00744-3. doi: 10.1016/j.prosdent.2024.11.002. Epub ahead of print. PMID: 39627077.
2. Gaikwad AM, Joshi AA, de Oliveira-Neto OB, Padhye AM, Nadgere JB, Ram SM, Yadav SR. An Overview of Systematic Reviews and Meta-analyses Evaluating Different Impression Techniques for Implant-Supported Prostheses in Partially and Completely Edentulous Arches. Int J Oral Maxillofac Implants. 2022 Nov-Dec;37(6):1119-1137. doi: 10.11607/jomi.9635. PMID: 36450017.
3. Carneiro Pereira AL, Medeiros VR, da Fonte Porto Carreiro A. Influence of implant position on the accuracy of intraoral scanning in fully edentulous arches: A systematic review. J Prosthet Dent. 2021 Dec;126(6):749-755. doi: 10.1016/j.prosdent.2020.09.008. Epub 2020 Oct 23. PMID: 33268069.
4. Papaspyridakos P, Chen CJ, Gallucci GO, Doukoudakis A, Weber HP, Chronopoulos V. Accuracy of implant impressions for partially and completely edentulous patients: a systematic review. Int J Oral Maxillofac Implants. 2014 Jul-Aug;29(4):836-45. doi: 10.11607/jomi.3625. PMID: 25032763.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The present paper deal with a relevant topic in actuality which necessitate an effort from authors to acknowledge. However; there are important drawbacks that may be considered; because evidence syntheses are commonly regraded as the foundation of evidence based dentistry.

some suggestions are provided below

Introduction:

An effort was made by authors to provide a conceptual framework for the manuscript; however; there are elements that require improvement.

1-    Its essential to consider the definition of these terms “survival” ; “effectiveness”; “success rate” in the introduction. Some confusion may arise when considering the overall background information’s provided

2-    Please expend on the diversity observed by authors

3-    The aim of this SR should be revised to be aligned with the primary outcome and secondary objectives.

A thorough revision of the introduction is suggested to enhance the value of the introduction

Material and Methods

Reference to taxonomies used to classify included studies is relevant. However, there are some points that I suggest reviewing. Categories of papers included by authors should be reconsidered. For example: different terms were used: prospective; controlled; randomized trials which may seems some confusion. Because risk of bias tools and assessment are based on this definition; I suggest to reconsider papers included to provide a clear definition of the study design

Authors are invited to define clearly data extracted from included studied.

Does authors consider publications bias

Does reliability between authors were assessed

I suggest reviewing that there are some drawbacks to help enhancing quality of this paper

Discussion

I suggest reviewing the order of the discussion in terms of being consistent with the primary aim and secondary objectives

The discussion does not include an analysis of the strength and limitations of the this systematic review

Conclusion

The conclusion should be reconsidered based on the objectives of the study

NB. Based on authors responses additional comments may be added

Author Response

Reviewer 2:

 

The present paper deal with a relevant topic in actuality which necessitate an effort from authors to acknowledge. However; there are important drawbacks that may be considered; because evidence syntheses are commonly regraded as the foundation of evidence based dentistry.

some suggestions are provided below

Introduction:

An effort was made by authors to provide a conceptual framework for the manuscript; however; there are elements that require improvement.

 

R.: We would like to thank the reviewer for evaluating our manuscript. We have made substantial changes to it. We respectfully refer the Reviewers to the comments and our detailed responses to Reviewers #’s 1-2, it was rewritten and restructured. We carefully considered all criticisms and believed that we were able to fully address the points raised, improving the overall quality of the manuscript significantly. All your notes were recorded in blue.

 

1-    Its essential to consider the definition of these terms “survival” ; “effectiveness”; “success rate” in the introduction. Some confusion may arise when considering the overall background information’s provided

R.: A reference to the literature used in defining terms was added. We included the topic in the methodology section, as it presents the data extraction criteria.

2-    Please expend on the diversity observed by authors

R.: The diversity of articles and methodologies used in the different articles that make up the sample is highlighted throughout the results section. Several additional devices and protocols were observed in the studies, especially regarding digital methodology. This digital revolution in our field holds the potential to significantly impact the effectiveness of clinical studies. Clinically, due to the small number of articles, it is impossible to clarify which method(s) or device(s) has the most significant impact on the effectiveness of the digital method. This is highlighted in the discussion.

 

 

 

3-    The aim of this SR should be revised to be aligned with the primary outcome and secondary objectives.

R.: the paragraph regarding the objective was revised to better reflect the primary and secondary outcomes observed.

A thorough revision of the introduction is suggested to enhance the value of the introduction

R.: We appreciate the feedback and would like to emphasize that the introductory section has been completely revamped.

 

Material and Methods

1. Reference to taxonomies used to classify included studies is relevant. However, there are some points that I suggest reviewing. Categories of papers included by authors should be reconsidered. For example: different terms were used: prospective; controlled; randomized trials which may seems some confusion. Because risk of bias tools and assessment are based on this definition; I suggest to reconsider papers included to provide a clear definition of the study design

R.: To address any potential conflicts, the descriptions of the included and excluded articles were revised. Specifically, clinical studies that utilized both digital and conventional impression methods were included if they had more than five participants and provided adequate data on the survival rates and complications of the prostheses. Additionally, studies that exclusively employed the digital impression method but still allowed for the collection of relevant data were also considered. Given the variety of study types in the sample, different scales were necessary to analyze the risk of bias to ensure that the evaluation method did not compromise the study scores. Therefore, the ROB-2 scale was applied to randomized studies, while the ROBINS-I scale was used for non-randomized studies.

2. Authors are invited to define clearly data extracted from included studied.

R.: Quantitative and qualitative data were meticulously extracted from the studies as described in Tables 1 and 2 during data tabulation. However, given the diversity of methodologies observed in the studies, only five studies presented similar characteristics that allowed the construction of a meta-analysis on data regarding impression time, number of repetitions, survival rate, and marginal bone loss observed. We restructured these paragraphs in the methodology, the proposal is aligned with the data collected.

 

 

4. Does authors consider publications bias

R.: Yes, we consider the application of the ROB and ROBINS-I scales. Additionally, we included certainty of evidence analysis (GRADE).

5. Does reliability between authors were assessed

R.: In terms of inter-author reliability during the study selection process, we want to emphasize that any disagreements about including articles in the sample were addressed in group meetings. Additionally, to enhance the reliability of the results obtained from the meta-analyses, we incorporated a GRADe analysis. This approach enables us to evaluate the certainty of the evidence across the studies utilized.

I suggest reviewing that there are some drawbacks to help enhancing quality of this paper

R.: To enhance the robustness of the study, the disadvantages of both digital and conventional methodologies were discussed in the Discussion. We have included new information and references in the section.

 

Discussion

I suggest reviewing the order of the discussion in terms of being consistent with the primary aim and secondary objectives

R.: Consequently, the discussion session was reorganized to follow the same sequence of topics outlined in the objectives. We reviewed the manuscript's objectives, and accordingly, the sequence of results in the meta-analysis was reformulated.

 

The discussion does not include an analysis of the strength and limitations of the this systematic review

R.: The limitations highlighted by the studies in the sample, along with the constraints of the proposed review, were clearly articulated. Additionally, we included the GRADE analysis for the systematic review.

 

Conclusion

The conclusion should be reconsidered based on the objectives of the study

R.: The final session was redesigned to more effectively meet the objectives of the study.

 

We recognize and value the essential feedback provided by the review and editorial team, which significantly improved our study.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

I consider that the alterations to the manuscript were critical to improve the scientifical soundness and precision of the outcomes  in the systematic review. Congratulations for the work.

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks to the authors for responding to comments