title: Peri-implant bone organization surrounding zirconia-microgrooved surfaces circularly polarized light and confocal laser scanning microscopy study.
abstract: OBJECTIVE
  To study the peri-implant bone organization pattern of immediately loaded (IL) zirconia implants with microgrooved surfaces.
  
  
  METHODS
  Forty-eight dental implants of 4 mm diameter and 10 mm length were inserted after two months postextraction healing in the edentulous mandible of six dogs. Three groups of sixteen implants were used, titanium implants (Control), zirconia implants (test A), and zirconia-microgrooved implants (test B), which were loaded immediately. After 4-month healing period, implant-bone samples were processed and analyzed by circularly polarized light (CPL) and confocal laser scanning microscopy (CLSM) in two regions of interest ROI1 (to evaluate the interthread bone) and ROI2 (to evaluate the bone adjacent to the threads) of 1 mm thickness × 10 mm length each one.
  
  
  RESULTS
  Bone organization differs near to the test B, compared with test A and control surfaces, active remodeling was detected surrounding test B implants, with alternancy of organized zones, meanwhile controls and test A areas showed organized areas mainly at 2 mm of implant surfaces. Transverse collagen fibers were significatively higher at ROI1 for test B implants (60.34 ± 4.34%), compared with controls (47.25 ± 3.51%) and test A (43.78 ± 2.78%) groups (P < 0.05). Meanwhile, it was not found any significant difference between groups in ROI2 (P > 0.05). CLSM confirmed the presence of collagen mineralized matrix inside microgrooves of test B groups. 3D reconstruction showed blood vessels in direct contact with the implant surfaces of all groups and bone and blood vessels penetration inside the microgrooves in test B group.
  
  
  CONCLUSIONS
  The organized pattern of the microgrooved surfaces is able to induce transverse collagen fiber microenvironment reaction to the load, being positive to promote and to maintain the bone remodeling; in addition blood vessels and bone cells are able to penetrate microgrooved surfaces.
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Rafael Arcesio
authors.initials: RA
authors.lastname: Delgado-Ruiz
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Marcus
authors.initials: M
authors.lastname: Abboud
authors.affiliation: School of Medicine and Dentistry, Granada University, Granada, Spain.
authors.forename: Georgios
authors.initials: G
authors.lastname: Romanos
authors.affiliation: School of Medicine and Dentistry, Granada University, Granada, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Aguilar-Salvatierra
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Gomez-Moreno
authors.affiliation: School of Medicine and Dentistry, Murcia University, Murcia, Spain.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Calvo-Guirado
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D003094:Collagen / Q000378:metabolism; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003764:Dental Materials; D004285:Dogs; D007150:Immunohistochemistry; D008297:Male; D008334:Mandible / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D018613:Microscopy, Confocal; D015040:Zirconium
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D003094:Collagen; D015040:Zirconium; C028541:zirconium oxide
keywords: circularly polarized light; collagen fiber orientation; confocal laser scanning microscopy; dental implants; immediate loading; osseointegration