Abstract
This study investigated the bactericidal effect, the underlying mechanisms of treatment, and recovery of biocompatibility of the infected titanium surface using a combination treatment of silver ion application and ultraviolet-A (UV-A) light irradiation. Streptococcus mutans and Aggregatibacter actinomycetemcomitans were used in suspension and as a biofilm on a titanium surface to test for the bactericidal effect. The bactericidal effect of the combination treatment was significantly higher than that of silver ion application or UV-A light irradiation alone. The bactericidal effect of the combination treatment was attributable to hydroxyl radicals, which generated from the bacterial cell wall and whose yield increased with the silver concentration. To assess the biocompatibility, proliferation and calcification of MC3T3E1 cells were evaluated on the treated titanium surface. The treated titanium screws were implanted into rat tibias and the removal torques were measured 28 days post-surgery. The titanium surface that underwent the combination treatment exhibited recovery of biocompatibility by allowing cellular proliferation or calcification at levels observed in the non-infected titanium surfaces. The removal torque 28 days after surgery was also comparable to the control values. This approach is a novel treatment option for peri-implantitis.
Highlights
This study investigated the bactericidal effect, the underlying mechanisms of treatment, and recovery of biocompatibility of the infected titanium surface using a combination treatment of silver ion application and ultraviolet-A (UV-A) light irradiation
The different treatment groups were classified as follows: Ag(+)L(+): Mixture of silver nitrate solution and bacterial suspension followed by UV-A light irradiation, Ag(+) L(−): Mixture of silver nitrate solution and bacterial suspension followed by incubation in a light-shielding box, Ag(−)L(+): Mixture of ultrapure water and bacterial suspension followed by UV-A light irradiation, and Ag(−) L(−): Mixture of ultrapure water and bacterial suspension followed by incubation in a light-shielding box
The bactericidal effect in samples diluted with Mueller Hinton Broth (MHB) was 7.2 ± 0.1 log CFU, while those in samples diluted with ultrapure water, or 10% albumin solution were 4.3 ± 0.3, and 6.2 ± 0.1 log CFU, respectively, and significantly lower than the value for MHB
Summary
This study investigated the bactericidal effect, the underlying mechanisms of treatment, and recovery of biocompatibility of the infected titanium surface using a combination treatment of silver ion application and ultraviolet-A (UV-A) light irradiation. The bactericidal effect of the combination treatment was significantly higher than that of silver ion application or UV-A light irradiation alone. The application of silver ions to an infected dental implant surface is expected to demonstrate effective bactericidal activity. We have previously demonstrated that photodynamic therapy, using ultraviolet-A (UV-A) light irradiation with hydrogen peroxide or caffeic acid, has a high bactericidal effect and improves the titanium surface[35,36,37]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
