title: Efficacy of Gutta-Percha and Polytetrafluoroethylene Tape to Microbiologically Seal the Screw Access Channel of Different Prosthetic Implant Abutments.
abstract: OBJECTIVE
  To evaluate in vitro, the efficacy of gutta-percha (GP) and polytetrafluoroethylene (PTFE) tape to act as a seal against the penetration of Escherichia coli through prosthetic implant abutments (PIA) with external hexagon (EH) and morse taper (MT) connections.
  
  
  METHODS
  120 sets of implant analogs with their respective PIA were used. 60 sets from each system were divided into four groups (n = 15): I - GP sealing; II - PTFE tape sealing; III - no sealing (NS) and IV - negative control. Microbiological challenge was performed by placing bacterial colonies inside the titanium PIA before screwing them into their respective analogs. Each set was immersed in 5 mL of BHI and incubated for 14 days with daily checks for contamination, according to the nutrient medium turbidity.
  
  
  RESULTS
  The type of seal used influenced microbial penetration at all evaluation times (p < 0.05). Compared to GP, PTFE led to an increase in turbidity and its effectiveness against microbial penetration was equivalent to group NS. When the sealing efficacy of each group was compared in terms of time, Cochran's Q test revealed that in the two groups sealed with PTFE, there was a progressive increase in the number of turbid nutrient media (p < 0.0001), while in the group sealed with GP, this was only observed in the MT system (p = 0.0310).
  
  
  CONCLUSIONS
  Sealing the PIA channel with GP was a significantly superior approach to sealing it with PTFE tape. PTFE tape or NS led to a progressive increase in microbiological leakage over time in PIA channels, however, this only occurred with GP in the MT system.
authors: São Leopoldo Mandic Institute, Dental Research Center, Campinas, SP, Brazil.
authors: Alexei Gama de Albuquerque
authors: AG
authors: Cavalcanti
authors: São Leopoldo Mandic Institute, Dental Research Center, Campinas, SP, Brazil.
authors: Fernando Toledo Arruda
authors: FT
authors: Fonseca
authors: São Leopoldo Mandic Institute, Dental Research Center, Campinas, SP, Brazil.
authors: Camila D'Acampora Reis
authors: CD
authors: Zago
authors: São Leopoldo Mandic Institute, Dental Research Center, Campinas, SP, Brazil.
authors: Rui Barbosa
authors: RB
authors: Brito Junior
authors: São Leopoldo Mandic Institute, Dental Research Center, Campinas, SP, Brazil.
authors: Fabiana Mantovani Gomes
authors: FM
authors: França
mesh_terms: D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D015921:Dental Implants / Q000382:microbiology*; D003763:Dental Leakage / Q000382:microbiology / Q000517:prevention & control*; D006171:Gutta-Percha; D006801:Humans; D008422:Materials Testing; D011138:Polytetrafluoroethylene; D014025:Titanium
chemical_list: D015921:Dental Implants; D006171:Gutta-Percha; D011138:Polytetrafluoroethylene; D014025:Titanium
keywords: abutment-prosthesis interface; contamination; dental implant; microleakage; prosthetic implant abutment