دانلود رایگان ترجمه مقاله اثرات ضد قارچی ماده پوشش بهساز بافت با فوتوکاتالیز TiO2 (نشریه J-Stage 2005)

اثرات ضد قارچی ماده پوشش بهساز بافت با فوتوکاتالیز TiO2

Antifungal Effects of a Tissue Conditioner Coating Agent with TiO2 Photocatalyst

Tissue conditioners are susceptible to colonization by microorganisms. Therefore, the prevention of biofilm formation are important for oral hygiene. However, mechanical and chemical cleaning methods may cause clinical problems such as deformation or surface degradation of tissue conditioners. The objective of this study is to evaluate the antifungal effects of coating agents with a TiO2 photocatalyst. Photocatalytic antifungal effects on C. albicans biofilms and photodegradation effects of adsorbed protein were measured by colorimetric assays. Scanning electron microscopy was used to examine morphological changes in C. albicans. Viscosities of coating agents increased with incorporation of TiO2. However, both of coating agents with TiO2 were acceptable to the application by brush. The antifungal and protein degradation effects increased with the concentration of TiO2 in the coating agents. These effects also increased with radiation time. After 90 min radiation, the viability of C.albicans was reduced to 16.2±۳٫۳ %. Scanning electron microscopy observation showed C. albicans remained on the coated surfaces even after 90 min radiation. These results suggest that coating agents with TiO2 photocatalyst can be effective for the maintenance of tissue conditioners when dentures are removed; during sleep.

۱ Introduction

Tissue conditioners that improve the health of abused denture-bearing tissues are more susceptible to colonization by microorganisms than denture base resins1 . Most microorganisms colonizing on the surface are found as complex-structured microbial communities (biofilms) and may irritate the underlying tissue2-4. Therefore, maintenance of tissue conditioners and the prevention of biofilm formation are important for oral hygiene. However, mechanical and chemical cleaning methods may cause clinical problems such as deformation or surface degradation of tissue conditioners5,6.

Several studies have attempted to incorporate antibacterial agents into tissue conditioners for plaque control and treatment of denture stomatitis. However, the elution behavior of antibacterial agents has not been completely clarified and the salivary pellicles may inhibit the antibacterial agents from contacting with microbes7-10.

A TiO2 photocatalyst, which produces free radicals on its surfaces by adequate light activation, has come to utilization such as self-cleaning11, antibacterial12, and waste water purification13 component. Additionally, a TiO2 photocatalyst is chemically and physically stable and safe enough to be used as an additive for foods and cosmetics. These advantages have drawn much attention recently in the field of dental materials and some studies have been performed concerning the antifungal effect14-16. However, antifungal effects on biofilms that show much stronger resistance to antibacterial agents than the planktonic form17-20 have not yet been reported in the previous studies.

We incorporated a TiO2 photocatalyst into a coating agent for a tissue conditioner because it is important to expose a great number of TiO2 particles on the surface of the tissue conditioner. In addition, coating agents are an effective method to reduce plaque accumulation of tissue conditioners21,22. The purpose of this study was to investigate the antifungal effects of coating agents with a TiO2 photocatalyst on biofilms. In the successful colonization and development of pathogenesis, the adherence of C. albicans to polymers such as soft lining materials is essential and necessary first step, followed by the growth of adherent cells or the co-adhesion of floating cells to adherent ones23,24. Therefore we examined the viability of biofilm-grown C. albicans and observed C. albicans on the radiated coating surfaces by scanning electron microscopy (SEM). Moreover, we investigated the degradation of adsorbed protein that promotes microorganism accumulation25.