Jlio C' M' Souza, PhD student

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Universidade do Minho
Biotribocorrosion behavior of titanium in
different simulated oral environments
Functionalized Materials and Surfaces Performance
Júlio C. M. Souza, PhD student Jean-Pierre
Celis Luís Augusto Rocha
Department of Metallurgy and Materials
Engineering (MTM) Katholieke Universiteit Leuven,
Belgium
Department of Periodontology, School of
Dentistry Katholieke Universiteit Leuven, Belgium
Centre of Biological Engineering (CEB) Institute
for Biotechnology and Bioengineering Biological
Engineering Department University of Minho
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Introduction
Implant-supported prosthesis
Temperature
pH
Biofilms
Oral fluids
H2O2
Biotribocorrosion
HF-
Mastication forces
Dietary
Late failures of implant-supported prostheses are
related to factors such as over-load on the
system (design), biofilm accumulation, and
periodontal bone loss
S.M. Heckmann et al. J. Dent. (2006) N. Broggini
et al. J. Dent. Res (2006) J.S. Guindy et al.
Int. Jour. Oral Max. Impl. (2004) G. Mabileau et
al. Acta Biomat. (2006)
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Main aim
Study the degradation by simultaneous
corrosion-wear (biotribocorrosion) of titanium in
different simulated oral environments
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Materials and Methods
Tribocorrosion set up
Ft tangential force FN- normal force µ -
coefficient of friction µ Ft / FN
-Artificial saliva -Fluoride solutions -Oral
biofilms
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Results and Discussion
CORROSION
Localized corrosion of titanium in 12300 ppm F-
solution
12300 ppm F-
0 ppm F-
227 ppm F-
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Results and Discussion
TRIBOCORROSION
in artificial saliva (0 ppm F-)
Sliding at 3 N Coefficient of friction - 0.5
Oxide particles ejection
Ti layers detachment
Ti layers ejection
D.Landolt, S.Mischler, M.Stemp, S.Barril. Wear.
256 (2004)
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Results and Discussion
TRIBOCORROSION
in 12300 ppm F-
Sliding at 3 N Coefficient of friction - 0.3
cracks in the titanium oxide film
Amorphous complex oxide film can decrease the
friction on the surface
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Results and discussion
titanium surface
Pseudohyphae morphology of C.albicans
S.mutans
C.albicans multiplying by budding (yeast form)
Mixed biofilms grown for 9 days on CP-Ti examined
by SEM-FEG at a angle of 60o
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Results
BIOTRIBOCORROSION
Significant decrease of COF of titanium covered
with biofilms
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Results
BIOTRIBOCORROSION
C.albicans
Extracellular matrix
200 mN
100 mN
Mixed biofilms grown for 9 days on CP-Ti after
sliding test in artificial saliva
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Discussion
Movement of sliding
Al2O3
detachment
Extracellular matrix
rupture of extracellular matrix
rolls
Mucin, H2O
Wear particles
TiO2
Titanium surface
Titanium surface
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Conclusions

• Localized corrosion was noticed on titanium at
  high F- concentration.
• The simultaneous corrosion-wear process
  (tribocorrosion) is increased at high F-
  concentration and can promote the degradation of
  implant-supported prosthesis
• There is a significant decrease of friction on
  titanium in presence of biofilms (COF 0.5 ?
  0.05).
• Low friction in sliding contacts may cause a loss
  of mechanical integrity of dental implant-based
  systems (e.g. loosening of internal connection).

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Aknowledgements
Centre of Biological Engineering (CEB) Institute
for Biotechnology and Bioengineering Biological
Engineering Department Universidade do Minho
Universidade do Minho
Department of Metallurgy and Materials
Engineering (MTM) Periodontology department,
School of Dentistry Katholieke Universiteit
Leuven, Belgium

• Research Group on Functionalized Materials and
  Surfaces Performance
• Centre for Mechanical and Materials Technologies,
  CT2M
• Mechanical Engineering Department
• Escola de Engenharia/Universidade do Minho
  Campus de Azurém, 4800-058 Guimarães, Portugal
• 351 253 510220 ? 351 253 510007
• ? ct2m_at_uminho.pt

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Thank you for your attention!
Natal/RN, Brazil