Photocatalytic antibacterial effect of TiO(2) film of TiAg on Streptococcus mutans.
OBJECTIVE
To test through various oxidation procedures the differences in antibacterial activities against Streptococcus mutans (S mutans) of Titanium (Ti) and Titanium silver (TiAg) metals coated with TiO(2).


METHODS
This study examined the photocatalytic antibacterial effects on S mutans of Ti and TiAg ubstrates coated with two crystalline forms of TiO(2) by thermal and anodic oxidation. A bacterial suspension of S mutans was pipetted onto TiO(2)-coated metal specimens and uncoated specimens with ultraviolet A (UVA) illumination for 20 to 100 minutes. The same specimen without UVA was used as the control. The level of colony-forming units of S mutans after UVA illumination was compared with that of the control.


RESULTS
The level of colony-forming units of S mutans was significantly lower on TiO(2)-coated Ti and TiAg metal specimens after UVA illumination than on uncoated Ti and TiAg specimens. The level of colony-forming units of S mutans was significantly lower on the metals coated by anodic oxidation than on those coated by thermal oxidation. The TiO(2) coating on TiAg had a significantly higher and more rapid antibacterial effect than did the TiO(2) coating on Ti.


CONCLUSIONS
The antibacterial effect of a TiO(2) film formed by anodic oxidation was superior to that formed by thermal oxidation. The addition of Ag to the Ti specimen indicated a synergistic effect on the photocatalytic antibacterial property against S mutans.
Department of Orthodontics, Yongdong Severance Dental Hospital, College of Dentistry, Institute of Craniofacial Deformity, Oral Science Research Center, Yonsei University, Seoul, South Korea.
Jung-Yoon
JY
Choi
Chooryung Judi
CJ
Chung
Keun-Taek
KT
Oh
Yoon-Jeong
YJ
Choi
Kyung-Ho
KH
Kim
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003722:Dental Alloys / Q000494:pharmacology*; D004572:Electrolysis; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D012834:Silver / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects* / Q000528:radiation effects; D013997:Time Factors; D014025:Titanium / Q000494:pharmacology*; D014466:Ultraviolet Rays / Q000145:classification
D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; C009495:titanium dioxide; D012834:Silver; D014025:Titanium