title: A novel approach for enhanced nanoparticle-sized bone substitute adhesion to chemically treated peri-implantitis-affected implant surfaces: an in vitro proof-of-principle study.
abstract: BACKGROUND
  The objective of this study is to evaluate micro and nano-hydroxyapatite (NHA) blended clot adhesion to citric acid-conditioned peri-implantitis-affected surfaces.
  
  
  METHODS
  Forty hopeless implants with peri-implantitis designated for removal were included in this study. Implants were divided into eight groups of five each: group 1 (G1) test areas were coated with hydroxyapatite of a microparticle size (MHA); group 2 (G2) test areas were coated with NHA; group 3 (G3) implants were coated with MHA after surface conditioning using citric acid; group 4 (G4) samples were treated in the same manner as in G3 except for the use of NHA; group 5 (G5) samples were coated without surface treatment with MHA mixed with whole human blood; group 6 (G6) implant samples were treated in the same manner as in G5 except for the use of NHA; group 7 (G7) implant samples were treated in the same way as in G5 plus surface conditioning using citric acid; and group 8 (G8) samples were treated in the same manner as in G7 except for the use of NHA. All implants in all groups were agitated for 3 minutes in phosphate-buffered saline. All samples were prepared for scanning electron microscopy evaluation.
  
  
  RESULTS
  G1 and G2 non-etched implants coated with MHA or NHA sizes were devoid of any bone particle adhesion to the peri-implantitis-affected surfaces. Contrary to the lack of microparticle adhesion to the root surface that was seen in G3, G4 acid-treated and NHA-coated samples revealed nearly complete coverage of the peri-implantitis-affected parts by the graft material. G5 non-etched, clot-blended MHA showed some areas of clot-blended graft adhesion covering 6.7% of the examined surfaces. G6 non-etched, clot-blended NHA showed NHA retention within the fibrin strands in areas where the implant surface pores were exposed (24.3%). G7 acid-treated and clot-blended MHA-treated implant surfaces showed partial coverage of the implant surface with detached fibrin clot-blended graft material (31.4%). G8 acid-treated and NHA clot-blended graft-coated implants showed complete coverage of the implant surface by the clot-blended graft material (93.4%).
  
  
  CONCLUSIONS
  Peri-implantitis-affected surface conditioning with citric acid improves NHA-blended clot adhesion to titanium implant surfaces.
authors.affiliation: Department of Periodontology, Faculty of Dental Medicine, El-Azhar University, Cairo, Egypt.
authors.forename: Ahmed Y
authors.initials: AY
authors.lastname: Gamal
authors.forename: Khaled A
authors.initials: KA
authors.lastname: Abdel-Ghaffar
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Iacono
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D000328:Adult; D001777:Blood Coagulation; D018786:Bone Substitutes / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry*; D005337:Fibrin / Q000737:chemistry / Q000648:ultrastructure; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D057873:Peri-Implantitis / Q000473:pathology*; D016062:Porosity; D011446:Prospective Studies; D016037:Single-Blind Method; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D018786:Bone Substitutes; D015921:Dental Implants; D003764:Dental Materials; D019343:Citric Acid; D005337:Fibrin; D017886:Durapatite; D014025:Titanium