Effect of fluoride content on ion release from cast and selective laser melting-processed Co-Cr-Mo alloys.
BACKGROUND
Selective laser melting (SLM) alloy is gaining popularity in prosthetic dentistry. However, its biocompatibility has been of some concern because of long-term exposure to fluoride in the oral environment.


OBJECTIVE
The purpose of this study was to examine the effect of fluoride concentration on ion release from Co-Cr-Mo alloy specimens fabricated using either SLM or lost-wax casting when immersed in an artificial saliva solution containing fluoride.


METHODS
Specimens were prepared with either a SLM system for the SLM alloy or conventional lost-wax techniques for the cast alloy. The specimen surfaces were wet ground with silicon carbide paper (400, 800, and 1200 grit) and immersed in modified artificial saliva solutions, the pH of which had been adjusted to 5.0 with lactic acid and which contained NaF at concentrations of 0.00%, 0.05%, 0.1%, or 0.2%. The metal ion content of the solution was determined with an inductively coupled plasma mass spectrometer. The results were submitted to 2-way ANOVA and regression analysis (α=.05).


RESULTS
Fluoride concentration significantly influenced the elemental ion release from both the SLM and cast alloys. The quantity of ions released increased significantly with increasing fluoride concentration. The ion release from the cast specimens was significantly greater than that from the SLM specimens.


CONCLUSIONS
The performance of the SLM alloy in immersion tests demonstrates that this new technique is a superior choice because of its good biocompatibility.
Postgraduate student, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China.
Xu
X
Yang
Postgraduate student, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Nan
N
Xiang
Associate Professor, Department of Prosthodontics, Stomatology Special Consultation Clinic, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address: shjydentist@hotmail.com.
Bin
B
Wei
D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D002327:Cariostatic Agents / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D003735:Dental Casting Technique / Q000295:instrumentation; D003775:Dental Polishing / Q000379:methods; D004058:Diffusion; D005459:Fluorides / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007101:Immersion; D019344:Lactic Acid / Q000737:chemistry; D007834:Lasers; D008422:Materials Testing; D008982:Molybdenum / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D013054:Spectrophotometry, Atomic; D013499:Surface Properties
D017554:Carbon Compounds, Inorganic; D002327:Cariostatic Agents; D002858:Chromium Alloys; D012464:Saliva, Artificial; D017655:Silicon Compounds; D002857:Chromium; D019344:Lactic Acid; D003035:Cobalt; D008982:Molybdenum; D012969:Sodium Fluoride; D005459:Fluorides; C022088:silicon carbide