title: Influence of hydroxyapatite granule size, porosity, and crystallinity on tissue reaction in vivo. Part A: synthesis, characterization of the materials, and SEM analysis.
abstract: OBJECTIVE
  The aim of this study was the synthesis and analysis of the tissue reaction to three different Hydroxyapatite (HA)-based bone substitute materials differing only in granule size, porosity, and crystallinity through an animal experimental model at 60 days.
  
  
  METHODS
  Three different HA-based biomaterials were synthesized and characterized by X-ray diffraction, SEM, and EDS analysis, the resultant product was ground in three particle sizes: Group I (2000-4000 μm), Group II (1000-2000 μm), and Group III (600-1000 μm). Critical size defects were created in both tibias of 15 rabbits. Four defects per rabbit for a total of 60 defects were grafted with the synthesized materials as follows: Group I (15 defects), Group II (15 defects), Group III (15 defects), and empty (15 defects control). After animals sacrifice at 60 days samples were obtained and processed for SEM and EDS evaluation of Ca/P ratios, elemental mapping was performed to determine the chemical degradation process and changes to medullary composition in all the four study groups.
  
  
  RESULTS
  The tendency for the density was to increase with the increasing annealing temperature; in this way it was possible to observe that the sample that shows highest crystallinity and crystal size corresponding to that of group I. The SEM morphological examination showed that group III implant showed numerous resorption regions, group II implant presented an average resorption rate of all the implants. The group I displayed smoother surface features, in comparison with the other two implants.
  
  
  CONCLUSIONS
  The data from this study show that changing the size, porosity, and crystallinity of one HA-based bone substitute material can influence the integration of the biomaterials within the implantation site and the new bone formation.
authors.affiliation: International Research Cathedra, UCAM, Universidad Católica San Antonio, Murcia, Spain. jemate@ucam.edu.
authors.forename: José E
authors.initials: JE
authors.lastname: Maté Sánchez de Val
authors.affiliation: International Research Cathedra, UCAM, Universidad Católica San Antonio, Murcia, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.affiliation: Periodontology and Implant Dentistry, Pharmacological Research in Dentistry Group, Special Care in Dentistry, Faculty of Dentistry, University of Granada, Granada, Spain.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Gómez-Moreno
authors.affiliation: Murcia University, Murcia, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Pérez-Albacete Martínez
authors.affiliation: Departamento de Materiales, Óptica y Tecnologia Electrónica, Universidad Miguel Hernández, Avda. Universidad s/n, Elche (Alicante), Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Mazón
authors.affiliation: Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. Universidad s/n, Elche (Alicante), Spain.
authors.forename: Piedad N
authors.initials: PN
authors.lastname: De Aza
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000737:chemistry*; D003460:Crystallization; D017886:Durapatite / Q000138:chemical synthesis / Q000737:chemistry*; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D010316:Particle Size; D016062:Porosity; D011817:Rabbits; D013499:Surface Properties; D013977:Tibia / Q000601:surgery; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D017886:Durapatite
keywords: 
  SEM
  ; 
  in vivo
  ; characterization; hydroxyapatite; synthesis