Diamondlike Carbon Surface Treatment Improves the Fatigue Resistance of Ultrasonic Tips

Emmanuel J N L Silva; Bruno M Crozeta; Jorge N R Martins; Thiago Moreira; Victor T L Vieira; Francisco Manuel Braz-Fernandes; Marco A Versiani

doi:10.1016/j.joen.2022.12.008

Diamondlike Carbon Surface Treatment Improves the Fatigue Resistance of Ultrasonic Tips

J Endod. 2023 Mar;49(3):301-306. doi: 10.1016/j.joen.2022.12.008. Epub 2022 Dec 23.

Authors

Emmanuel J N L Silva¹, Bruno M Crozeta², Jorge N R Martins³, Thiago Moreira², Victor T L Vieira², Francisco Manuel Braz-Fernandes⁴, Marco A Versiani⁵

Affiliations

¹ Department of Endodontics, Grande Rio University, Rio de Janeiro, RJ, Brazil; Department of Endodontics, Fluminense Federal University, Niterói, RJ, Brazil; Department of Endodontics, Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil. Electronic address: nogueiraemmanuel@hotmail.com.
² Department of Endodontics, Grande Rio University, Rio de Janeiro, RJ, Brazil.
³ Department of Endodontics, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Unidade de Investigação em Ciências Orais e Biomédicas, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal; Centro de Estudo de Medicina Dentária Baseada na Evidência, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal.
⁴ CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal.
⁵ Oral Health Center, Brazilian Military Police, Unai, MG, Brazil.

PMID: 36567061
DOI: 10.1016/j.joen.2022.12.008

Abstract

Introduction: The aim of this study was to compare E1-Irrisonic (Helse Ultrasonics, Ocoee, FL) and Irri Black (Helse Ultrasonics), a novel ultrasonic tip with diamondlike carbon treatment, regarding their design, metallurgy, microhardness, bending resistance, and time to fracture under the oscillatory fatigue test.

Methods: A total of 17 E1-Irrisonic and 17 Irri Black new ultrasonic tips were selected. The tip geometry and surface finishing were assessed using scanning electron microscopy. The elemental composition was defined by energy-dispersive X-ray spectroscopy. Hardness Knoop was calculated using a microhardness tester. The maximum load required to displace the instrument in 45° was recorded in gram/force, oscillatory fatigue was measured in seconds at the moment of instrument fracture, and the size of the separate fragments was determined in millimeters. The Student t test was used for statistical comparison (α = 5%).

Results: Scanning electron microscopic analyses revealed that E1-Irrisonic had a flat end tip, whereas a noncutting rounded tip was observed in Irri Black. The surface of E1-Irrisonic was smoother than Irri Black, which was irregular. Energy-dispersive X-ray spectroscopic analyses showed that the elemental compositions of the E1-Irrisonic and Irri Black tips were consistent with stainless steel and titanium-aluminum alloys, respectively. Irri Black showed significantly higher bending load resistance, time to fracture under oscillatory motion, and hardness Knoop than the E1-Irrisonic tip (P < .05), whereas the length of fragments was similar (P > .05).

Conclusion: Diamondlike carbon treatment improved hardness Knoop and reduced the flexibility of the Irri Black ultrasonic tip, improving its time to fracture under oscillatory motion compared with the nontreated E1-Irrisonic tip.

Keywords: Bending resistance; diamond-like carbon coating; endodontics; fatigue resistance; metallurgical characteristics; ultrasonic tips.

MeSH terms

Carbon*
Equipment Design
Hardness
Humans
Materials Testing
Microscopy, Electron, Scanning
Root Canal Preparation
Surface Properties
Titanium / chemistry
Ultrasonics*

Substances

Carbon
Titanium