title: Fabrication and characterization of biomimetic ceramic/polymer composite materials for dental restoration.
abstract: OBJECTIVE
  Conventional dental composites with randomly dispersed inorganic particles within a polymer matrix fail to recapitulate the aligned and anisotropic structure of the dentin and enamel. The aim of the study was to produce a biomimetic composite consisting of a ceramic preform with graded and continuously aligned open pores, infiltrated with epoxy resin.
  
  
  METHODS
  The freeze casting technique was used to obtain the hierarchically structured architecture of the ceramic preforms. Optical and scanning electron microscopy (SEM) and differential thermal analysis and thermogravimetry (TG-DTA) were used to characterize the samples. Three point bending test and compression test were also performed.
  
  
  RESULTS
  All analysis confirmed that the biomimetic composite was characterized by a multi-level hierarchical structure along the freezing direction. In the bottom layers close to the cooling plate (up to 2mm thick), a randomly packed ceramic with closed pores were formed, which resulted in incomplete infiltration with resin and resultant poor mechanical propertiesof the composite. Above 2mm, all ceramic samples showed an aligned structure with an increasing lamellae spacing (wavelength) and a decreasing wall thickness. Mechanical tests showed that the properties of the composites made from ceramic preforms above 2mm from cooling plate are similar to those of the dentin.
  
  
  CONCLUSIONS
  The fabrication processing reported in this work offers a viable route for the fabrication of biomimetic composites, which could be potentially used in a range of dental restorations to compete with the current dental composites and ceramics.
authors.affiliation: Dental Materials Laboratory, Department of Medical, Oral and Biotechnological Science, University G. D'Annunzio, Chieti, Italy. burnich@hotmail.it
authors.forename: Morena
authors.initials: M
authors.lastname: Petrini
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ferrante
authors.forename: Bo
authors.initials: B
authors.lastname: Su
mesh_terms: D000180:Acrylic Resins / Q000138:chemical synthesis*; D000537:Aluminum Oxide / Q000737:chemistry*; D040761:Biomimetic Materials / Q000138:chemical synthesis*; D002516:Ceramics / Q000737:chemistry*; D003188:Composite Resins / Q000138:chemical synthesis*; D004055:Differential Thermal Analysis; D055119:Elastic Modulus; D004852:Epoxy Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D011140:Polyurethanes / Q000138:chemical synthesis*; D013499:Surface Properties; D013818:Thermogravimetry
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D004852:Epoxy Compounds; D011140:Polyurethanes; D000537:Aluminum Oxide