Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary Files
This study aimed to compare the fatigue resistance of files made from different heat treatment methods and surface treatment. Four prototype files were created through heat treatment and titanium coating surface treatment (AT, DT, ER, EN; named arbitrarily by the manufacturer) at different times and...
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MDPI AG
2023-10-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/13/10/1769 |
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| author | Jihye Hong Sang Won Kwak Jung-Hong Ha Asgeir Sigurdsson Ya Shen Hyeon-Cheol Kim |
| author_facet | Jihye Hong Sang Won Kwak Jung-Hong Ha Asgeir Sigurdsson Ya Shen Hyeon-Cheol Kim |
| author_sort | Jihye Hong |
| collection | DOAJ |
| description | This study aimed to compare the fatigue resistance of files made from different heat treatment methods and surface treatment. Four prototype files were created through heat treatment and titanium coating surface treatment (AT, DT, ER, EN; named arbitrarily by the manufacturer) at different times and temperatures. Artificial canals with curvatures of 45- and 90-degree were used for the fatigue testing. The files were operated at the speed of 500 rpm at 37 °C, and the time until fracture incurred by a 4-mm dynamic pecking motion at a speed of 8 mm/s was measured, and the number of cycles to failure (NCF) was calculated by applying rotation speed and time. The length of the fractured fragment was measured. The fractured specimens were observed under the SEM to compare the characteristics of fatigue fracture patterns. Differential scanning calorimetry analysis was performed to estimate the phase transformation temperature. One-way ANOVA with Duncan’s post-hoc comparison, the Kruskal–Wallis test, and Mann–Whitney U were applied to compare the fatigue resistance among the prototypes at a significance level of 95%. Regardless of the canal angle, the EN showed the highest fatigue resistance (<i>p</i> < 0.05). AT had the lowest NCF at the 90-degree canal (<i>p</i> < 0.05). ER had a higher NCF than the DT at 45 degrees (<i>p</i> < 0.05), but there was no difference at 90 degrees. DSC analysis revealed that the ER and EN groups exhibited two austenite peaks above 40 °C. In conclusion, the file that underwent a specific temperature heat treatment with titanium coating surface treatment showed the highest fatigue resistance. |
| first_indexed | 2024-03-10T21:02:44Z |
| format | Article |
| id | doaj.art-905a4445c633450f81e345248f732c08 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T21:02:44Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-905a4445c633450f81e345248f732c082023-11-19T17:22:43ZengMDPI AGMetals2075-47012023-10-011310176910.3390/met13101769Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary FilesJihye Hong0Sang Won Kwak1Jung-Hong Ha2Asgeir Sigurdsson3Ya Shen4Hyeon-Cheol Kim5Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Dental and Life Science Institute, Pusan National University, Yangsan 50612, Republic of KoreaDepartment of Conservative Dentistry, School of Dentistry, Dental Research Institute, Dental and Life Science Institute, Pusan National University, Yangsan 50612, Republic of KoreaDepartment of Conservative Dentistry, College of Dentistry, Kyungpook National University, Daegu 41940, Republic of KoreaDepartment of Endodontics, New York University College of Dentistry, New York, NY 10010, USADepartment of Oral Biological and Medical Sciences, Division of Endodontics, Faculty of Dentistry, University of British Columbia, Vancouver, BC V6T 1Z3, CanadaDepartment of Conservative Dentistry, School of Dentistry, Dental Research Institute, Dental and Life Science Institute, Pusan National University, Yangsan 50612, Republic of KoreaThis study aimed to compare the fatigue resistance of files made from different heat treatment methods and surface treatment. Four prototype files were created through heat treatment and titanium coating surface treatment (AT, DT, ER, EN; named arbitrarily by the manufacturer) at different times and temperatures. Artificial canals with curvatures of 45- and 90-degree were used for the fatigue testing. The files were operated at the speed of 500 rpm at 37 °C, and the time until fracture incurred by a 4-mm dynamic pecking motion at a speed of 8 mm/s was measured, and the number of cycles to failure (NCF) was calculated by applying rotation speed and time. The length of the fractured fragment was measured. The fractured specimens were observed under the SEM to compare the characteristics of fatigue fracture patterns. Differential scanning calorimetry analysis was performed to estimate the phase transformation temperature. One-way ANOVA with Duncan’s post-hoc comparison, the Kruskal–Wallis test, and Mann–Whitney U were applied to compare the fatigue resistance among the prototypes at a significance level of 95%. Regardless of the canal angle, the EN showed the highest fatigue resistance (<i>p</i> < 0.05). AT had the lowest NCF at the 90-degree canal (<i>p</i> < 0.05). ER had a higher NCF than the DT at 45 degrees (<i>p</i> < 0.05), but there was no difference at 90 degrees. DSC analysis revealed that the ER and EN groups exhibited two austenite peaks above 40 °C. In conclusion, the file that underwent a specific temperature heat treatment with titanium coating surface treatment showed the highest fatigue resistance.https://www.mdpi.com/2075-4701/13/10/1769nickel-titanium filefatiguefracture resistanceheat treatmentsurface treatment |
| spellingShingle | Jihye Hong Sang Won Kwak Jung-Hong Ha Asgeir Sigurdsson Ya Shen Hyeon-Cheol Kim Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary Files Metals nickel-titanium file fatigue fracture resistance heat treatment surface treatment |
| title | Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary Files |
| title_full | Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary Files |
| title_fullStr | Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary Files |
| title_full_unstemmed | Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary Files |
| title_short | Effect of Different Heat Treatments and Surface Treatments on the Mechanical Properties of Nickel-Titanium Rotary Files |
| title_sort | effect of different heat treatments and surface treatments on the mechanical properties of nickel titanium rotary files |
| topic | nickel-titanium file fatigue fracture resistance heat treatment surface treatment |
| url | https://www.mdpi.com/2075-4701/13/10/1769 |
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