In vitro evaluation of biocompatibility of experimental titanium alloys for dental restorations.
BACKGROUND
Applications of titanium casting to fixed and removable prostheses have not been satisfactory because of the high melting point of titanium and its great reactivity with mold materials. Low-melting titanium alloys would alleviate many casting problems. At the present time, low-melting titanium alloys are not available for clinical dental use.


OBJECTIVE
The study evaluated the safety of 2 prototype low-melting titanium casting alloys for their future development for dental restorations. The 2 experimental titanium alloys were titanium-cobalt(Ti 81.4% wt, Co 18.6% wt) and titanium-silver (Ti 75% wt, Ag 25% wt). Commercially pure titanium and a commonly used nickel-chromium-based dental alloy were also included for comparison.


METHODS
Assays for evaluating mutagenicity and cytotoxicity were Ames salmonella/microsome mutagenicity spot test, agar diffusion method, and cell attachment assay.


RESULTS
The results of Ames test showed that none of the experimental titanium alloys, pure titanium, or nickel-chromium samples were mutagenic. There were no leachable components to cause cellular lysis or decolorization in the agar diffusion assay from the 4 group metals. The results of the cell attachment assay demonstrated that there was no significant difference in the numbers of cells attached to the 4 group metals. However, the mean number of cells attached to nickel-chromium samples was significantly lower than that of the control group.


CONCLUSIONS
On the basis of the data obtained from this study, it is concluded that the prototype Ti alloys are not mutagenic and imposes minimal risks associated with cytotoxicity.
Wang
R R
RR
Department of Restorative Dentistry, Case Western Reserve University, School of Dentistry, Cleveland, Ohio, USA.
Li
Y
Y
D000362:Agar; D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002858:Chromium Alloys / Q000737:chemistry / Q000494:pharmacology; D003035:Cobalt / Q000737:chemistry / Q000494:pharmacology; D003722:Dental Alloys / Q000737:chemistry* / Q000494:pharmacology; D003734:Dental Casting Investment / Q000737:chemistry / Q000494:pharmacology; D003793:Dental Restoration, Permanent; D004058:Diffusion; D005069:Evaluation Studies as Topic; D008422:Materials Testing; D008669:Metallurgy; D051379:Mice; D008861:Microsomes / Q000187:drug effects; D009153:Mutagens / Q000494:pharmacology; D012475:Salmonella / Q000187:drug effects; D012834:Silver / Q000737:chemistry / Q000494:pharmacology; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology
D001672:Biocompatible Materials; D002858:Chromium Alloys; D003722:Dental Alloys; D003734:Dental Casting Investment; D009153:Mutagens; D003035:Cobalt; D012834:Silver; D000362:Agar; D014025:Titanium