title: Apatite formation on dental ceramics modified by a bioactive glass.
abstract: Restorative dental materials are considered biocompatible without exhibiting any bioactive behaviour. The aim of this study was the investigation of surface structure changes on conventional dental ceramics used in metal-ceramic restorations modified by a bioactive glass, after immersion in SBF for various time periods. Bioactive glass powder was mixed with porcelain powder with three different weight ratios: 1:1, 1:2, and 2:1. The two powders were mixed with porcelain modelling liquid and the mixture was transferred and spread on the surface of pre-fabricated ceramic disks. Coated ceramic specimens after being exposed to a specific thermal cycle as it is recommended for dental ceramics were soaked in Simulated Body Fluid (SBF) at 37 degrees C for various periods of time. After soaking, specimens were studied using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Results revealed the development of a non-stoichiometric, biological apatite layer on their surface after exposure in SBF for several time periods. The onset of apatite-layer formation is directly dependent on the amount of bioglass in the coating and its thickness reduces within the specimens of the same bioactive glass-porcelain proportion with time, reaching an average thickness of 15 microm at the longest immersion time, for all the specimens.
authors.affiliation: Department of Fixed Prosthesis and Implants Prosthodontics, Aristotle University of Thessaloniki, Dental School, Thessaloniki, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Kontonasaki
authors.forename: L
authors.initials: L
authors.lastname: Papadopoulou
authors.forename: T
authors.initials: T
authors.lastname: Zorba
authors.forename: E
authors.initials: E
authors.lastname: Pavlidou
authors.forename: K
authors.initials: K
authors.lastname: Paraskevopoulos
authors.forename: P
authors.initials: P
authors.lastname: Koidis
mesh_terms: D001031:Apatites / Q000138:chemical synthesis*; D001672:Biocompatible Materials / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D003764:Dental Materials; D019554:Dental Restoration Wear; D006801:Humans; D008855:Microscopy, Electron, Scanning / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013499:Surface Properties
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; C022107:Bioglass; D003764:Dental Materials