Impact of Contracted Endodontic Access Cavity on Shaping Ability of Hyflex Electrical Discharge Machining Single File Using Cone Beam Computed Tomography: An Ex Vivo Study


  • Ahmed Bayoumi Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
  • Magdy Mohamed Aly Department of Endodontics, Faculty of Dentistry, Minia University, Minya, Egypt; Department of Endodontics, Faculty of Dentistry, Egyptian Russian University, Badr City, Egypt
  • Reham Hassan Department of Endodontics, Faculty of Dentistry, Minia University, Minya, Egypt; Department of Endodontics, Faculty of Dentistry, Egyptian Russian University, Badr City, Egypt



HyFlex electrical discharge machining, Cone-beam computed tomography, Traditional access, Contracted access, Canal transportation, Centering ability, Control memory, Nickel-titanium instruments


AIM: The aim of the study was to evaluate and compare the effect of different access cavity designs, using cone-beam computed tomography (CBCT), on root canal transportation, and centralization performed on two rooted maxillary premolars.

METHODS: Twenty maxillary premolars were randomly divided into two groups. In Group 1, traditional endodontic cavities (TECs) were prepared. In Group 2, contracted endodontic cavities (CECs) were prepared. Mechanical preparation was done by HyFlex electrical discharge machining (EDM) single file in both groups. CBCT imaging was performed pre- and post-root canal preparation for calculations of root canal transportation and centering ability.

RESULTS: Data were analyzed using Mann–Whitney U test and Kruskal–Wallis test. For transportation, teeth with CECs showed the statistically significantly highest median amount of transportation, while as for centering ability, results showed no significant difference between both groups.

CONCLUSION: Under the conditions of this study, HyFlex EDM prepared canals with different access cavity designs without significant shaping errors. TEC showed less transportation than CEC, while both TEC and CEC had no effect on the file centering ability.


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How to Cite

Bayoumi A, Magdy Mohamed Aly, Hassan R. Impact of Contracted Endodontic Access Cavity on Shaping Ability of Hyflex Electrical Discharge Machining Single File Using Cone Beam Computed Tomography: An Ex Vivo Study. Open Access Maced J Med Sci [Internet]. 2021 Oct. 10 [cited 2024 Jun. 17];9(D):221-8. Available from:



Dental Pathology and Endodontics