title: Self-cleaning effects of acrylic resin containing fluoridated apatite-coated titanium dioxide.
abstract: OBJECTIVE
  Specific materials when used in the manufacture of dentures can enhance the elimination of micro-organisms to promote oral hygiene. We used Candida albicans adhesion assays, methylene blue (MB)-decomposition tests and mechanical property tests to evaluate the photocatalytic properties of acrylic resin containing fluoridated apatite-coated titanium dioxide (FAp-TiO2 ) after treatment with ultraviolet A (UVA) irradiation.
  
  
  BACKGROUND
  Conventional denture cleaning methods are unable to completely eliminate micro-organisms from dentures.
  
  
  METHODS
  Test specimens were prepared using acrylic resin containing three types of TiO2 powder [FAp-TiO2, titanium dioxide (TiO2 ) and hydroxyapatite-coated TiO2 (HAp-TiO2 )]; n = 96. In the adhesion assay, test specimens were incubated in a fungal suspension and subjected to UVA irradiation, and the number of attachments of C. albicans on the test specimens was counted. The MB-decomposition test and the three-point bending test were then performed to assess the photocatalytic effects of the FAp-TiO2 -containing acrylic resin.
  
  
  RESULTS
  Fluoridated apatite-coated titanium dioxide-containing acrylic resin demonstrated superior effectiveness in inhibiting C. albicans adherence as well as in decomposing MB. In the three-point bending test, the resin showed a smaller decrease in flexural strength compared with TiO2 - or HAp-TiO2 -containing acrylic resin. Furthermore, UVA irradiation for 360 h did not significantly influence its flexural strength or elasticity modulus as compared with the control; this fulfils the requirements of International Organization for Standardization 1567:1999.
  
  
  CONCLUSIONS
  Fluoridated apatite-coated titanium dioxide-containing acrylic resin is a clinically suitable material that promotes proper denture hygiene, particularly for elderly persons requiring nursing care or who have a decreased ability to perform normal activities of daily living.
authors.affiliation: Division of Fixed Prosthodontics, Department of Oral and Maxillofacial Rehabilitation, Kanagawa Dental College, Yokosuka, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Sawada
authors.forename: Tomoji
authors.initials: T
authors.lastname: Sawada
authors.forename: Tomonari
authors.initials: T
authors.lastname: Kumasaka
authors.forename: Nobushiro
authors.initials: N
authors.lastname: Hamada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shibata
authors.forename: Toru
authors.initials: T
authors.lastname: Nonami
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kimoto
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D001031:Apatites / Q000737:chemistry / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects / Q000502:physiology; D002384:Catalysis; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003819:Denture Bases / Q000382:microbiology; D017886:Durapatite / Q000737:chemistry; D055119:Elastic Modulus; D006801:Humans; D008751:Methylene Blue / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry / Q000494:pharmacology; D010782:Photolysis; D018583:Pliability; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D000180:Acrylic Resins; D001031:Apatites; D020099:Coated Materials, Biocompatible; D003764:Dental Materials; D016877:Oxidants; C009495:titanium dioxide; D017886:Durapatite; D014025:Titanium; C025105:fluorapatite; D008751:Methylene Blue
keywords: TiO2 photocatalysis; acrylic resin; mechanical property; self-cleaning effect