title: In Vitro Microbiological Analysis of Bacterial Seal in Hybrid Zirconia Abutment Tapered Connection.
abstract: OBJECTIVE
  The aim of this study was to evaluate the bacterial seal at the implant-hybrid zirconia abutment interface and Morse taper-type connections through in vitro microbiological analysis.
  
  
  METHODS
  Sixteen implants and their respective abutments were divided into 3 groups: test (10 sets), positive control (3 sets), and negative control (3 sets). In the test group, 10 implants were contaminated with Escherichia coli using a sterile inoculating loop to the inner portion of the implants, followed by torque application to the abutment (30 N·cm). The positive controls were also contaminated, but no torque was applied to the abutment screw. The negative control consisted of uncontaminated sets. All specimens were immersed in test tubes containing 5 mL brain heart infusion (BHI) broth, maintained in a microbiological incubator for 14 days at 37°C under aerobic conditions, and monitored every 24 hours for evidence of bacterial growth.
  
  
  RESULTS
  During the 14 days of incubation, no significant increase in the number of cloudy culture media was observed in the test group (P = 0.448). No significant difference in broth turbidity ratio was observed (P > 0.05).
  
  
  CONCLUSIONS
  Hybrid zirconia abutments can create an effective seal at the tapered abutment-implant interface with a 30-N·cm installation torque.
authors.affiliation: *Master Student, Department of Implantology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil. †Professor, Department of Implantology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil. ‡Professor, Department of Immunology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil. §Professor, Department of Oral Pathology and Cell Biology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil.
authors.forename: Maurício Marcelo
authors.initials: MM
authors.lastname: Harlos
authors.forename: Thiago
authors.initials: T
authors.lastname: Bezerra da Silva
authors.forename: Daiane C
authors.initials: DC
authors.lastname: Peruzzo
authors.forename: Marcelo H
authors.initials: MH
authors.lastname: Napimoga
authors.forename: Julio Cesar
authors.initials: JC
authors.lastname: Joly
authors.forename: Elizabeth F
authors.initials: EF
authors.lastname: Martinez
mesh_terms: D001419:Bacteria; D003470:Culture Media; D000044:Dental Abutments / Q000382:microbiology*; D059605:Dental Implant-Abutment Design; D066298:In Vitro Techniques; D015040:Zirconium
chemical_list: D003470:Culture Media; D015040:Zirconium; C028541:zirconium oxide