title: Experimental models for contamination of titanium surfaces and disinfection protocols.
abstract: OBJECTIVE
  The aim of this pilot study was to describe an in vitro model of peri-implantitis microcosm for contamination of titanium surfaces and an in vivo model for evaluating different disinfection strategies of titanium surfaces.
  
  
  METHODS
  Biofilms were grown in vitro for 30 days on sandblasted large-grit acid-etched (SLA) Ti discs (n = 69) in a constant depth film fermentor (CDFF) associated with peri-implantitis conditions. Four Swedish loop rabbits were randomly allocated in three test groups (T1, T2, T3) and one control group (C). In group C, two sterile SLA Ti discs were implanted/fixed in each tibia. In the test groups (to evaluate the potential of different surface disinfection techniques), one sterile and three previously disinfected SLA Ti discs were placed following different disinfection protocols: group T1: the discs were treated with a titanium brush - TiB; group T2: the discs were treated with the combination of TiB and photodynamic therapy; and group T3: the discs were treated with TiB and 1%NaOCl plus 0.2%CHX. Tensile strength test and qualitative histological analysis were performed on all 16 discs after 4 weeks of healing.
  
  
  RESULTS
  Thirty days following CDFF emulating peri-implantitis microcosm, all SLA Ti discs had a mean total viable aerobes and facultative anaerobes count of 8.06 log10CFU/biofilm and anaerobes 8.32 log10CFU/biofilm. Before implantation/fixation on the tibia, differences of log10CFU/biofilm counts between control and test groups after post hoc adjustment were highly significant (P < 0.001). In the in vivo analysis, group C exhibited the highest tensile strength (67.60 N [25.64-127.02]) and the histological sections revealed the presence of dense mature bone in direct contact with the disc surface. The analysis at the test groups showed that T2presented with the highest tensile strength in comparison with the other two test groups.
  
  
  CONCLUSIONS
  The in vitro model used in this study provides a valuable and reproducible tool for evaluating the in vitro dynamics of the peri-implantitis microcosm biofilm and for contaminating in a reproducible manner titanium surfaces. At the same time, the in vivo model used in this study provides a standardised mode of evaluating disinfection modalities of previously infected titanium surfaces.
authors: Periodontology Unit, Department of Clinical Research, UCL Eastman Dental Institute, London, UK.|Department of Microbial Diseases, UCL Eastman Dental Institute, London, UK.
authors: Vanessa
authors: V
authors: Sousa
authors: Centre for Adult Oral Health, Periodontology Unit, QMUL Bart's and The London School of Dentistry and Hospital, London, UK.
authors: Nikos
authors: N
authors: Mardas
authors: Department of Microbial Diseases, UCL Eastman Dental Institute, London, UK.
authors: David
authors: D
authors: Spratt
authors: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK.
authors: David
authors: D
authors: Boniface
authors: Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, NY, USA.
authors: Michel
authors: M
authors: Dard
authors: Periodontology Unit, Department of Clinical Research, UCL Eastman Dental Institute, London, UK. n.donos@qmul.ac.uk.|Centre for Oral Clinical Research, Institute of Dentistry, Barts & The London School of Medicine & Dentistry, QMUL, London, UK. n.donos@qmul.ac.uk.
authors: Nikolaos
authors: N
authors: Donos
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology; D015921:Dental Implants / Q000382:microbiology*; D003764:Dental Materials; D004195:Disease Models, Animal; D004203:Disinfection / Q000379:methods*; D066298:In Vitro Techniques; D008962:Models, Theoretical; D057873:Peri-Implantitis / Q000473:pathology / Q000517:prevention & control*; D010778:Photochemotherapy; D010784:Photomicrography; D010865:Pilot Projects; D011817:Rabbits; D011897:Random Allocation; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013499:Surface Properties; D013977:Tibia / Q000473:pathology; D014025:Titanium
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D003513:Cycloheximide; D014025:Titanium; D012973:Sodium Hypochlorite
keywords: CDFF; biomaterials; bone implant interactions; histomorphometric analysis; microbiology; microcosm; preclinical study