title: Ultrastructural study by backscattered electron imaging and elemental microanalysis of biomaterial-to-bone interface and mineral degradation of bovine xenografts in maxillary sinus floor elevation.
abstract: OBJECTIVE
  The aim of this study was to perform an ultrastructural study of the bone-to-biomaterial interface and biomaterial mineral degradation in retrieved bone biopsies following maxillary sinus augmentation using bovine xenografts (Endobon(®)) 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 occurred during surgery. Scanning electron microscopy revealed that newly formed bone was closely attached to the xenograft. Elemental analysis showed a significantly high Ca/P ratio in the residual biomaterials (3.031 ± 0.104) compared with the interface (2.908 ± 0.115) and new bone (2.889 ± 0.113), 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 bovine biomaterial showed particle categories with different mean Ca/P ratios according to size, pointing to different stages of the resorption process.
  
  
  CONCLUSIONS
  The biomaterial proved to be biocompatible and osteoconductive when used as a bone substitute for maxillary sinus elevation. The grafting material used is not a completely resorbable material over the time period covered by this study.
authors.affiliation: Department of Implant Dentistry, Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain. mpramirezfern@hotmail.com
authors.forename: María Piedad
authors.initials: MP
authors.lastname: Ramírez-Fernández
authors.forename: José Luis
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.forename: Rafael Arcesio
authors.initials: RA
authors.lastname: Delgado-Ruiz
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Maté-Sánchez del Val
authors.forename: Bruno
authors.initials: B
authors.lastname: Negri
authors.forename: María Peñarrocha
authors.initials: MP
authors.lastname: Diago
mesh_terms: D000328:Adult; D000818:Animals; D001706:Biopsy; D002417:Cattle; D003094:Collagen / Q000494:pharmacology; D003758:Dental Implantation, Endosseous; D005260:Female; D064593:Heterografts; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation*; D008297:Male; D008443:Maxillary Sinus / Q000601:surgery / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D059546:Sinus Floor Augmentation; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D013524:Surgical Flaps; D016896:Treatment Outcome
chemical_list: D003094:Collagen