XRD Study of NiTi Endodontic Files Using Synchrotron Radiation · 2020-06-12 · XRD Study of NiTi...
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XRD Study of NiTi Endodontic Files Using Synchrotron Radiation F.M. Braz Fernandes 1 , J.P. Oliveira 2 , A. Machado 3 , N. Schell 4 1,2,3 CENIMAT – I3N, Campus da FCT/UNL, 2829-516 Monte de Caparica, Portugal. 4 Helmholtz-Zentrum Geesthacht, Inst. of Materials Research, Geesthacht, Germany Overview • Identification of the problem • Identification of the possible solution • Material issues: Superelasticity • Material testing • XRD analysis in flexion • Stress‐induced martensite • Future work
Transcript of XRD Study of NiTi Endodontic Files Using Synchrotron Radiation · 2020-06-12 · XRD Study of NiTi...
XRD Study of NiTi Endodontic FilesUsing Synchrotron Radiation
F.M. Braz Fernandes1, J.P. Oliveira2, A. Machado3, N. Schell4
1,2,3 CENIMAT – I3N, Campus da FCT/UNL, 2829-516 Monte de Caparica, Portugal.4 Helmholtz-Zentrum Geesthacht, Inst. of Materials Research, Geesthacht, Germany
Overview
• Identification of the problem
• Identification of the possible solution
• Material issues: Superelasticity
• Material testing
• XRD analysis in flexion
• Stress‐induced martensite
• Future work
The Problem
• Application: ENDODONTICS
€Fracture
Ni‐Ti
‐ Ni‐Ti alloys ‐ Superleasticity‐
Cooling
Heating
Shape memory Effect
Strain, ε (%)
Strain, ε
Strain, ε
Str
ess,
σ(M
Pa)
Str
ess,
σ
Str
ess,
σ
Below Mf
Temperature, T
Critical stress for dislocation slip (A)
Super-elasticity
Shape memory effect
Shape memory effect versus superelasticity
Cri
tical
stre
ss fo
r str
ess i
nduc
edm
arte
nsite
Critical stress for dislocation slip (B)
Above Af
Ni-Ti System
Ligasricas em Ti
Ligasricas em Ni
W. Tang, B. Sundman, R. Sandström, C. Qiu. Acta materialia 47 (1999) 3457-3468
Austenite(B2)
Cubic
Martensite(B19’)
Monoclinic
R-phase(R)
Rhombohedral
ndodontic filesaterial haracterization
-60 -40 -20 0 20 40 60-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
Flo
w (
mW
/g
)
Temperature (ºC)
Profile ® .06 (35)
10 samples 10 samples
Never used clinically
Used in 5 clinical cases
DSC DSC
Profile ® .06 (35)
10 samples 10 samples
Never used clinically
Never used clinically
Used in 5 clinical cases
Used in 5 clinical cases
DSC DSC
“Mechanism of NiTi file fracture based on rotation/flexion assays in three endodontic files”. S. Vilaverde Correia, R. J. C. Silva, M.T. Nogueira, R. F. Martins, L. Pires Lopes, F.M. Braz Fernandes. Actas de “11ª Jornadas Portuguesas de Fractura / 11th Portuguese Conference on Fracture” (ISBN 978-989-95683-0-3), pp 383- 392, Caparica, 2008.
Testing – Rotation / Flexion
TestingRotation / Flexion
Fracture of endodontfiles
“Mechanism of NiTi file fracture based on rotation/flexion assays in three endodontic files”. S. Vilaverde Correia, R. J. C. Silva, M.T. Nogueira, R. F. Martins, L. Pires Lopes, F.M. Braz Fernandes. Actas de “11ª Jornadas Portuguesas de Fractura / 11th Portuguese Conference on Fracture” (ISBN 978-989-95683-0-3), pp 383- 392, Caparica, 2008.
Endodontic files
RD Study of NiTi Endodontic Files Using ynchrotron Radiation
M-T
wo .
04(3
5)
ProFi
le .
04(3
5)
RD Study of NiTi Endodontic Files Using ynchrotron Radiation
Profile bent
Mtwo bent
RD Study of NiTi Endodontic Files Using ynchrotron Radiation
Endodontic files under flexion
Stress‐Induced martensite
Austenite
Martensite
0
50
100
150
200
250
300
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
Distance from tip height (mm)
Int.
B19
' (co
un
ts)
60
65
70
75
80
Int.
Bac
kgro
un
d (
cou
nts
)
Peak B19' (010)
Background at 2theta=1.6º
0
5
10
15
20
25
30
35
40
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
Distance from tip height (mm)
Int.
B19
' (co
un
ts)
70
75
80
85
90
95
100
Int.
Bac
kgro
un
d (
cou
nts
)
Peak B19' (010)
Background at 2theta=1.6º
RD Study of NiTi Endodontic Files Using ynchrotron Radiation
MTwo
Maximum Absorption of X‐rays
file
MTwoArbab‐Chirani . et al., “Comparative analysis of torsional and bending behavior through finite‐element models of 5 Ni–Ti endodontic instruments”. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology 111 (2011) 115‐121.
Profile
0
50
100
150
200
0 2 4 6 8 10
Distance from tip height (mm)
Int.
B19
(co
un
ts)
60
65
70
75
80
85
Int.
Bac
kgro
un
d (
cou
nts
)
Peak B19' (010)
Background at 2theta=1.6º
0
5
10
15
20
25
30
35
40
45
50
0 1 2 3 4 5 6
Distance from tip height (mm)
Int.
B19
(co
un
ts)
70
75
80
85
90
95
Int.
Bac
kgro
un
d (
cou
nts
)Peak B19' (010)
Background at 2theta=1.6º
MTwo
Profile
MTwo Profile
Conclusions
‐ Sress distribution in the cross‐section and stress‐induced martensite transformation is affected by geometry
‐ Exact location of stress concentration has been experimentaidentified
Future work
•Torsion tests
TORSIONAL TESTING OF RACE, K3 AND PROFILE Ni‐Ti ENDODONTIC FILESMSc Viginia University, 2004
mélioration d’une méthodologie d’analyse des données après des expériences
n-situ de diffraction à haute énergie pour un Alliage à Mémoire de Forme à
grains micrométriques
diant stagiaire : Younes ELHACHI
adré par : Benoît Malard – CIRIMAT , INP, Toulouse
3DXRD
Thank you
for your attention!
