In vitro corrosion behavior of bioceramic, metallic, and bioceramic-metallic coated stainless steel dental implants.
OBJECTIVE
The most common metals and alloys used in dentistry may be exposed to a process of corrosion in vivo that make them cytotoxic. The biocompatibility of dental alloys is primarily related to their corrosion behavior. The aim of this work was to evaluate the corrosion behavior and thus the biocompatibility of the uncoated and coated stainless steels and compare the effect of type of coatings on corrosion behavior.


METHODS
Three types of coatings, hydroxyapatite (HA), titanium (Ti), and a double-layer HA/Ti on AISI 316L stainless steel were made. HA coating was produced using plasma-spraying technique and Ti coating was made using physical vapor deposition process. In order to perform a novel double-layer composite coating, a top layer of HA was plasma-sprayed over a physical vapor deposited Ti layer on AISI 316L stainless steel. Structural characterization techniques including XRD, SEM and EDX were used to investigate the microstructure, morphology and crystallinity of the coatings. Electrochemical potentiodynamic tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens as an indication of biocompatibility.


RESULTS
Double-layer HA/Ti coating on AISI 316L SS had a positive effect on improvement of corrosion behavior. The decrease in corrosion current densities was significant for these coated specimens and was much lower than the values obtained for uncoated and single HA coated specimens. Ti coating on AISI 316L SS also has a beneficial effect on corrosion behavior. The results were compared with the results of corrosion behavior of HA coated commercially pure titanium (cpTi) and uncoated cpTi.


CONCLUSIONS
These results demonstrated that the double-layer HA/Ti coated 316L SS can be used as an endodontic implant and two goals including improvement of corrosion resistance and bone osteointegration can be obtained simultaneously.
Fathi
M H
MH
Department of Materials Engineering, Isfahan University of Technology, 84154, Isfahan, Iran. fathi@cc.iut.ac.ir
Salehi
M
M
Saatchi
A
A
Mortazavi
V
V
Moosavi
S B
SB
D001672:Biocompatible Materials / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003343:Corrosion; D003461:Crystallography; D003722:Dental Alloys / Q000737:chemistry*; D015921:Dental Implants; D017886:Durapatite / Q000737:chemistry; D004563:Electrochemistry; D004577:Electron Probe Microanalysis; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013193:Stainless Steel / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; D013193:Stainless Steel; D017886:Durapatite; D014025:Titanium