Preparation and antimicrobial assay of ceramic brackets coated with TiO 2 thin films

• Published in: Korean journal of orthodontics (2012) Vol. 46; no. 3; pp. 146 - 154
• Main Authors: Cao, Shuai, Wang, Ye, Cao, Lin, Wang, Yu, Lin, Bingpeng, Lan, Wei, Cao, Baocheng
• Format: Journal Article
• Language: Korean
• Published: Korean Association of Orthodontists 31.05.2016; 대한치과교정학회
• Subjects: Esthetics; Antibacterial; Ceramic brackets; Biomaterial science
• ISSN: 2234-7518; 2005-372X

Objective: Different methods have been utilized to prevent enamel demineralization and other complications during orthodontic treatment. However, none of these methods can offer long-lasting and effective prevention of orthodontic complications or interventions after complications occur. Considering the photocatalytic effect of $TiO_2$ on organic compounds, we hoped to synthesize a novel bracket with a $TiO_2$ thin film to develop a photocatalytic antimicrobial effect. Methods: The sol-gel dip coating method was used to prepare $TiO_2$ thin films on ceramic bracket surfaces. Twenty groups of samples were composed according to the experimental parameters. Crystalline structure and surface morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively; film thickness was examined with a surface ellipsometer. The photocatalytic properties under ultraviolet (UV) light irradiation were analyzed by evaluating the degradation ratio of methylene blue (MB) at a certain time. Antibacterial activities of selected thin films were also tested against Lactobacillus acidophilus and Candida albicans. Results: Films with 5 coating layers annealed at $700^{\circ}C$ showed the greatest photocatalytic activity in terms of MB decomposition under UV light irradiation. $TiO_2$ thin films with 5 coating layers annealed at $700^{\circ}C$ exhibited the greatest antimicrobial activity under UV-A light irradiation. Conclusions: These results provide promising guidance in prevention of demineralization by increasing antimicrobial activities of film coated brackets.