An antibacterial surface on dental implants, based on the photocatalytic bactericidal effect.
BACKGROUND
It is well known that the moderately roughened surfaces of dental implants enhance direct bone-implant contact. However, rough implant surfaces, as compared to smooth surfaces, are thought to pose a higher risk of bacterial infection when exposed to the oral cavity.


OBJECTIVE
This study was focused on evaluating the photocatalytic bactericidal effects of anatase titanium dioxide (TiO(2)) on gram-negative anaerobic bacteria known to be associated with periimplantitis.


METHODS
A film of photocatalytic anatase TiO(2) was added onto the surface of commercially pure titanium disks by plasma source ion implantation (PSII) followed by annealing. The photocatalytic properties of the film were confirmed by the degradation of methylene blue. Actinobacillus actinomycetemcomitans and Fusobacterium nucleatum cells were incubated anaerobically and seeded on the disk. The disks were then exposed to ultraviolet A (UVA) illumination from black light in an anaerobic environment. After illumination, the number of viable cells was counted in terms of colony-forming units.


RESULTS
The anatase TiO(2) film added by the PSII method and annealing exhibited a strong photocatalytic reaction under UVA illumination. The viability of both types of bacteria on the photocatalytic TiO(2) film was suppressed to less than 1% under UVA illumination within 120 minutes.


CONCLUSIONS
The bactericidal effect of the TiO(2) photocatalyst is of great use for sterilizing the contaminated surface of dental implants.
Division of Fixed Prosthodontics and Oral Rehabilitation, Department of Developmental and Reconstructive Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan. d401011r@stcc.nagasaki-u.ac.jp
Naoki
N
Suketa
Takashi
T
Sawase
Hideki
H
Kitaura
Mariko
M
Naito
Koumei
K
Baba
Koji
K
Nakayama
Ann
A
Wennerberg
Mitsuru
M
Atsuta
D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects / Q000528:radiation effects; D001421:Bacteria, Anaerobic / Q000187:drug effects* / Q000528:radiation effects*; D020099:Coated Materials, Biocompatible; D015169:Colony Count, Microbial; D003666:Decontamination / Q000379:methods; D003722:Dental Alloys; D015921:Dental Implants / Q000382:microbiology*; D016967:Fusobacterium nucleatum / Q000187:drug effects / Q000528:radiation effects; D007477:Ions; D008855:Microscopy, Electron, Scanning; D017319:Photosensitizing Agents / Q000494:pharmacology*; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology*; D014466:Ultraviolet Rays
D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; D007477:Ions; D017319:Photosensitizing Agents; C009495:titanium dioxide; D014025:Titanium