1 / 24

Vickers Hardness Study of M-Wire Endodontic Rotary Instruments

Vickers Hardness Study of M-Wire Endodontic Rotary Instruments. J. LIU 1 , S.B. ALAPATI 2 , W.A. BRANTLEY 1 , J.M. NUSSTEIN 1 , W.A.T. CLARK 1 , and M. IIJIMA 3 .

sumana
Download Presentation

Vickers Hardness Study of M-Wire Endodontic Rotary Instruments

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Vickers Hardness Study of M-Wire Endodontic Rotary Instruments J. LIU1, S.B. ALAPATI2, W.A. BRANTLEY1, J.M. NUSSTEIN1, W.A.T. CLARK1, and M. IIJIMA3. 1Ohio State University, Columbus, USA, 2Medical University of South Carolina, Charleston, USA, 3Health Sciences University of Hokkaido, Japan

  2. Outline • Background • Materials and Method • Results • Conclusion • Future Plan

  3. Background • What is root canal treatment • Removal of inflamed or necrotic pulp tissue and filling of the canal with therapeutic materials • Challenge of root canal treatment

  4. NiTi Rotary Endodontic Instruments ProFile ProFile GT ProTaper • ProFile Series (Dentsply,Tulsa Dental) • ProFile GT (Dentsply,Tulsa Dental) • ProTaper (Dentsply Maillefer) • Quantec Series (SybronEndo)

  5. Phase transformation of NiTi alloy Austenite: (BCC)high temperature and low stress Martensite: (Mono-Triclinic) low temperature and high stress R-phase: intermediate phase From Thompson SA.. International Endodontic Journal 2000 A R M

  6. Challenges/Disadvantages of Current NiTi Rotary Instrument • Intracanal fracture: • Prevalence around 5% (Parashos et al, 2006) • Retrieve is very difficult From Peters et al. Journal of Endo 2004

  7. New M-Wire Rotary Endodontic Instruments Prepared by special thermomechanical processing Clinical use has shown greater flexibility Greater resistance to cyclic fatigue Better cutting efficacy

  8. Significance of Our Study • To understand the phase and microstructure of the new M-wire rotary endodontic instrument • Our ultimate goal is to provide potential means for improving the clinical performance of NiTi rotary instruments

  9. My Current Study of M-Wire Rotary Endodontic Instrument • Differential Scanning Calorimetry Study • Microstructure Study • Micro-X –Ray Diffraction Study • Scan Electronic Microscope Study • Energy-Dispersive X-ray Spectroscopy Study • Vickers Hardness Study

  10. DSC (Differential Scanning Calorimetry) DSC curves for the three segments of the clinically used GTX 20/0.04

  11. Acid Etching &Optical Microscope Study M-Wire M-Wire Instrument

  12. SEM (Scan Electronic Microscope) Study Clinically used M-Wire Instrument Clinically used ProTaper Instrument It seems M-Wire file is more “dentin-resistant”.

  13. Correlation of Clinical Performance with Hardness Hardness is used to predict wear resistance and ability of NiTi rotary endodontic instruments to abrade tooth structure

  14. Primary Focus of this Presentation Study the variation of vickers hardness of M-Wire rotary endodontic instrument along the instrument shaft in • As-received condition • Clinically used condition • Compare with conventional NiTi rotary instruments

  15. Materials • M-Wire GT® Series X™ (Dentsply Tulsa Dental, Tulsa, OK) as-received and clinically used rotary nickel-titanium endodontic instruments were selected for study • Clinically used M-Wire instruments and conventional rotary instruments were subjected to seven to eight times clinical use by the same endodontist by OSU faculty practice

  16. Materials Preparation Diamond Saw cut Resin Mounted Polishing

  17. Micro-Hardness Tester • Diamond indenter • Main unit with CCD Camera and monitor • Test results as VHN

  18. Indentation Process • Indentation load: 300g • Five indentations in every segment • Each indentation is at the center and • equidistant adjacent locations in each segment

  19. P=0.002 P=0.028 P=0.304 Results Vickers Hardness of As Received M-Wire Instruments • Previous study has show the mean VHN of the intermediate part of the • ProFile instrument is 320

  20. VHN of As-Received and Used M-Wire Instruments No significant difference between the VHN of as-received and used M-Wire instruments

  21. VHN of Clinically Used M-Wire Instruments and Conventional Instruments P=0.008 P=0.000 P=0.000 There is significant difference between the VHN of clinically used M-Wire Instrument and conventional instrument

  22. Conclusion • M-wire instruments have significantly higher Vickers Hardness than conventional NiTi rotary instruments • This higher Vickers hardness may contribute to the better fatigue resistance and cutting efficiency of the new M-Wire instrument • TEM study has shown that the superior mechanical properties of M-Wire arise from the residual slip bands and twinned microstructure, which provide strengthening and increased deformation without fracture.

  23. Future Research Plan • NanoHardness measurement • Transmission Electronic Microscope

  24. Thanks Dr. Brantley School of Dentistry Ohio state university • Dr. Alapati • South Carolina Medical University college of Dentistry • Dr.Iijima • School of Dentistry, Health Sciences University of Hokkaido, Ishikari-tobetsu, Japan • Dr.Nusstein • Department of Endodontics • School of Dentistry • Ohio state university

More Related