Influence of endodontic cavity access on curved root canal preparation with ProDesign Logic rotary instruments



This study evaluates whether endodontic cavity access into molars influences the chemomechanical preparation of curved root canals.

Materials and methods

Twenty mesiobuccal canals of maxillary molars were randomly divided into two experimental groups (n = 10), according to the type of endodontic access analyzed (conventional and minimally invasive). The preparations were made by a single operator, and the canals, after access, were prepared with Logic system (0.25, 0.04 taper) along the working length. Samples were scanned before and after canal preparation (SMX-90CT Plus (Shimadzu® microtomograph operated with 70 kV, 100 uA, FOV (XY) 13.3 mm, FOV (Z) 7.0 mm, and voxel size 0.013 mm/Pix)) to match canal volumes. Images were analyzed to evaluate surface areas, transport, and centralization at 3 mm from the canal entrance and 3 mm from the apex (OnDemand3DTM Dental software). Student’s t test with a significance level of 5% was used for the statistical analysis.


Regardless of the position of the analyzed canals, there was no difference in the prepared area regarding the transport and centralization of the endodontic instrument between the two types of cavity accesses performed.


The conventional and minimally invasive access did not influence the action of the 0.25 and 0.04 taper instrument during the curved root canal preparation.

Clinical relevance

The type of endodontic access did not influence the action of the rotary instrument during the curved root canal preparation.

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The work was supported by the authors.

Author information




Gabiana Rodrigues Freitas: main researcher; contribution to carrying out the experiment and to analysis and interpretation of data and drafting of the article

Thais Marchand Ribeiro: contribution to carrying out the experiment

Fabiana Soares Grecca Vilella: contribution to the experimental design, review, and approval of the final version

Tiago André Fontoura de Melo: contribution to the conception and design of the manuscript, review, and approval of the final version

Corresponding author

Correspondence to Tiago André Fontoura de Melo.

Ethics declarations

This study was approved by the Research Ethics Committee of the Faculty of Dentistry of UFRGS and by the Research Ethics Committee of the same institution (Process CAAE 89366618.0.0000.5347).

Conflict of interest

The authors declare that they have no competing interests.

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This article does not contain any studies with human participants or animals performed by any of the authors.

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For this type of study, formal consent is not required.

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Freitas, G.R., Ribeiro, T.M., Vilella, F.S.G. et al. Influence of endodontic cavity access on curved root canal preparation with ProDesign Logic rotary instruments. Clin Oral Invest 25, 469–475 (2021).

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  • Endodontic access
  • Minimally invasive
  • Nickel-titanium instruments
  • Root canal preparation
  • Microcomputed tomography