Microtomographic Analysis of the Biomechanical Performance of Thermally Treated Instruments in Flattened and Curved Root Canals

Julia Godoi Lopes; Jeneffer Vieira Rodrigues; Iago Ramirez; Rafael Verardino de Camargo; Graziela Bianchi Leoni; Manoel Damião Sousa-Neto; Fabiane Carneiro Lopes-Olhê; Jardel Francisco Mazzi-Chaves

doi:10.1016/j.joen.2024.12.012

Microtomographic Analysis of the Biomechanical Performance of Thermally Treated Instruments in Flattened and Curved Root Canals

J Endod. 2024 Dec 20:S0099-2399(24)00693-9. doi: 10.1016/j.joen.2024.12.012. Online ahead of print.

Authors

Julia Godoi Lopes¹, Jeneffer Vieira Rodrigues¹, Iago Ramirez¹, Rafael Verardino de Camargo¹, Graziela Bianchi Leoni², Manoel Damião Sousa-Neto¹, Fabiane Carneiro Lopes-Olhê¹, Jardel Francisco Mazzi-Chaves³

Affiliations

¹ Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
² School of Dentistry, University of Ribeirão Preto, Ribeirão Preto, SP, Brazil.
³ Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil. Electronic address: jardel.chaves@usp.br.

PMID: 39710189
DOI: 10.1016/j.joen.2024.12.012

Abstract

Objectives: This study aimed to evaluate, using micro-computed tomography (microCT), the impact of various mechanized systems on the geometry of the root canal system (RCS) and dentin thickness in mandibular first molars. The hypothesis proposed that different systems would produce significant variations in RCS preparation.

Methods: Mesial and distal canals of mandibular molars were selected and divided into five groups (n=10) based on the system used: 2Shape (25.06), Reciproc Blue (25.08), ProTaper Ultimate (25.08), ProTaper Next (25.06), and Univy New (25.06). Biomechanical preparation was performed following each manufacturer's instructions. MicroCT scans were conducted before and after preparation to assess three-dimensional parameters (volume, surface area, SMI, and prepared root canal walls) and two-dimensional parameters (area, perimeter, diameters, roundness, and transportation).

Results: ProTaper Ultimate exhibited the greatest volume increase in mesial canals (1.73 ± 0.19), while ProTaper Next demonstrated the highest increase in distal canals (1.95 ± 0.25). Furthermore, ProTaper Ultimate resulted in the greatest dentin removal and the largest post-preparation area. Reciproc Blue achieved the best results for roundess and had the lower unprepared walls (15.3 ± 6.97).

Conclusions: All systems produced comparable outcomes, with ProTaper Ultimate yielding the greatest volume increase and dentin removal, indicating a less conservative preparation. Reciproc Blue provided optimal roundness and minimized unprepared root canal wall surfaces.

Keywords: MicroCT; biomechanical preparation; instrumentation.