title: Microleakage into and from two-stage implants: an in vitro comparative study.
abstract: OBJECTIVE
  Gaps between an abutment and a dental implant are unavoidable, and microleakage may occur, leading to problems such as malodor and peri-implantitis. The aim of the present in vitro study was to investigate leakage of Staphylococcus aureus through the implant/abutment interface by the method of bacterial culture, and to compare the leakage rates of two different types of implant-abutment connections.
  
  
  METHODS
  Twenty Morse taper implants with abutments were divided into two groups: group A, which were evaluated for microleakage into the inner part of the implants, and group B, which were evaluated for microleakage from the inner part of the implants. Twenty internal-hexagon implants with abutments were also divided into two groups: group C, which were evaluated for microleakage into the inner part of the implants, and group D, which were evaluated for microleakage from the inner part of the implants. For the evaluation of leakage from the implants, the assemblies had the inner parts inoculated with S aureus, and each assembly was incubated in sterile brain heart infusion broth for 1 week. For assessment of leakage into the implants, each assembly was submerged in 4 mL S aureus culture in tubes and incubated for 2 weeks. The microleakage of the two implant connections was compared.
  
  
  RESULTS
  Microbial leakage occurred in all groups, and there was no statistically significant difference between groups A and C or between groups B and D.
  
  
  CONCLUSIONS
  In vitro, S aureus leakage through the implant/abutment interface occurred with both Morse taper and internal-hexagon implants.
authors.affiliation: Department of Dental Materials and Prosthodontics, Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Brazil. wendelteixeira@gmail.com
authors.forename: Wendel
authors.initials: W
authors.lastname: Teixeira
authors.forename: Ricardo Faria
authors.initials: RF
authors.lastname: Ribeiro
authors.forename: Sandra
authors.initials: S
authors.lastname: Sato
authors.forename: Vinicius
authors.initials: V
authors.lastname: Pedrazzi
mesh_terms: D058491:Bacterial Load; D001431:Bacteriological Techniques; D003030:Coagulase / Q000032:analysis; D000044:Dental Abutments / Q000382:microbiology*; D015921:Dental Implants / Q000382:microbiology*; D003763:Dental Leakage / Q000382:microbiology*; D018772:Dental Marginal Adaptation; D017267:Dental Prosthesis Design; D006801:Humans; D008422:Materials Testing; D050296:Microbial Viability; D013211:Staphylococcus aureus / Q000201:enzymology / Q000302:isolation & purification*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D019415:Torque
chemical_list: D003030:Coagulase; D015921:Dental Implants