title: Evaluation of implant-abutment microgap and bacterial leakage in five external-hex implant systems: an in vitro study.
abstract: OBJECTIVE
  The aim of the present study was to verify the presence of a microgap between implants and prosthetic abutments on their external surfaces in five different external-hex implant systems and to determine whether bacterial leakage occurs through the implant-abutment (I-A) interface.
  
  
  METHODS
  Ten samples of each implant system were used. Eight samples of each implant system were inoculated with 0.3 μL of a suspension of Escherichia coli for bacterial leakage evaluation. Two other samples were used as controls. Sample analysis was accomplished at 24 and 48 hours and on the 5th, 7th, and 14th day after inoculation. After microbiologic analysis, all samples were prepared for I-A interface evaluation by scanning electron microscopy. The mean of the microgap misfit was obtained from six points at x1,000 and x3,000 magnifications.
  
  
  RESULTS
  The Neodent implant system (0.51 ± 0.39 μm) showed the closest adaptation, followed by Dentoflex (1.44 ± 0.73 μm), Titanium Fix (1.88 ± 1.28 μm), SIN (2.46 ± 3.38 μm), and Conexão (2.68 ± 3.02 Μm). Twenty-five percent of the Dentoflex samples showed bacterial leakage through the I-A interface; no other implant system presented bacterial leakage.
  
  
  CONCLUSIONS
  The width of the microgap at the I-A interface was less than 3 μm in all systems. A direct correlation between bacterial leakage and I-A interface misfit was not observed.
authors.affiliation: Grande Rio University-UNIGRANRIO Vitória, ES, Brazil. eduardodias@uol.com.br
authors.forename: Eduardo Cláudio Lopes de Chaves e Mello
authors.initials: EC
authors.lastname: Dias
authors.forename: Edecir Décio Cargnin
authors.initials: ED
authors.lastname: Bisognin
authors.forename: Nassim David
authors.initials: ND
authors.lastname: Harari
authors.forename: Sílvio Jorge
authors.initials: SJ
authors.lastname: Machado
authors.forename: Cristiano Pereira
authors.initials: CP
authors.lastname: da Silva
authors.forename: Glória Dulce de Almeida
authors.initials: GD
authors.lastname: Soares
authors.forename: Guaracilei Maciel
authors.initials: GM
authors.lastname: Vidigal
mesh_terms: D058491:Bacterial Load; D001431:Bacteriological Techniques; D000044:Dental Abutments / Q000382:microbiology*; D059605:Dental Implant-Abutment Design; D015921:Dental Implants / Q000382:microbiology*; D003763:Dental Leakage / Q000382:microbiology*; D018772:Dental Marginal Adaptation; D017267:Dental Prosthesis Design; D004926:Escherichia coli / Q000302:isolation & purification; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D013997:Time Factors
chemical_list: D015921:Dental Implants