title: Ultrastructural study by backscattered electron imaging and elemental microanalysis of bone-to-biomaterial interface and mineral degradation of porcine xenografts used in maxillary sinus floor elevation.
abstract: OBJECTIVE
  The aim of this study was to carry out an ultrastructural study of the biomaterial-to-bone interface and biomaterial mineral degradation in retrieved bone biopsies following maxillary sinus augmentation using collagenized porcine xenografts (Osteobiol(®) Mp3) in 15 clinical cases.
  
  
  METHODS
  Nine months after sinus lifting, bone cores were harvested from the maxillary sinus. The specimens were processed for observation under a scanning electron microscope with backscattered electron imaging (SEM-BSE). In addition, chemical analysis and elemental mapping of the mineral composition were generated using a microanalytical system based on energy-dispersive X-ray spectrometry (EDX).
  
  
  RESULTS
  No clinical complications were evident during surgery. Scanning electron microscopy revealed that newly formed bone had become closely attached to the xenograft. Statistical analysis showed a significantly high Ca/P ratio in the biomaterial (2.46 ± 0.16) and at the bone interface (2.00 ± 0.48) compared to bone (1.97 ± 0.36), which suggests that there may be a gradual diffusion of Ca ions from the biomaterial into the newly forming bone at the interface as part of the biomaterial's resorption process. EDX analysis of the residual porcine biomaterial at different points showed some particle categories with different mean ratios of Ca/P according to size, pointing to different stages of the resorption process.
  
  
  CONCLUSIONS
  The biomaterial proved to be biocompatible, bioreabsorbable and osteoconductive when used as a bone substitute for maxillary sinus elevation. SEM-BSE revealed that newly formed bone had become closely attached to the xenografts. EDX analysis monitored the resorption process of the porcine bone xenograft. Elemental mapping showed that there was a gradual diffusion of Ca ions from the biomaterial to the newly forming bone at the interface.
authors.affiliation: Department of Implant Dentistry, Faculty of Medicine and Dentistry, University of Murcia, Spain. mpramirezfern@hotmail.com
authors.forename: Maria Piedad
authors.initials: MP
authors.lastname: Ramírez-Fernández
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.forename: Jose Eduardo
authors.initials: JE
authors.lastname: Maté-Sánchez Del Val
authors.forename: Rafael Arcesio
authors.initials: RA
authors.lastname: Delgado-Ruiz
authors.forename: Bruno
authors.initials: B
authors.lastname: Negri
authors.forename: Cristina
authors.initials: C
authors.lastname: Barona-Dorado
mesh_terms: D000328:Adult; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001706:Biopsy; D018786:Bone Substitutes / Q000494:pharmacology*; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D005260:Female; D064593:Heterografts; D006801:Humans; D008297:Male; D008443:Maxillary Sinus / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D059546:Sinus Floor Augmentation; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D013552:Swine; D014183:Transplantation, Heterologous; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D015921:Dental Implants; C586522:osteobiol