Polytetrafluoroethylene added to acrylic resin: surface properties and Candida albicans adherence.
OBJECTIVE
To evaluate the surface properties and Candida albicans adherence on two acrylic resins, one polymerized by long cycle and the other by short polymerization cycle, with added 2% PTFE (wt/wt) (experimental groups) or not added (control groups).


METHODS
The specimens were divided into four groups (n = 10 per group): (1) acrylic resin polymerized by long cycle; (2) acrylic resin polymerized by long cycle with added 2% PTFE; (3) acrylic resin polymerized by short cycle; and (4) acrylic resin polymerized by short cycle with added 2% PTFE. After finishing and polishing, all specimens were assessed for their surface roughness (pm), contact angle (degree) and surface free energy (erg/cm 2) Saliva-coated specimens were submitted to the adherence assay with C. albicans (ATCC 90028). Adhered cells were detached from the acrylic resin surface by ultrasonic waves at 7 watts for 30 seconds in phosphate buffered saline solution (PBS). This cell solution was serially diluted in PBS and plated on Sabouraud agar. The results were expressed in colony forming units per surface area (CFU/mm2). The data was analyzed by two-way ANOVA. The significance limit was set at 5%.


RESULTS
No statistical differences were found for roughness, contact angle and surface free energy. There was a reduction trend in C. albicans adherence in PTFE added to resins, but it was not statistically significant.
Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Sao Paulo, Brazil.
Fabiana Gouveia
FG
Straioto
Renata
R
Alves
Antonio Pedro Ricomini
AP
Filho
Altair Antoninha
AA
Del Bel Cury
D000180:Acrylic Resins / Q000737:chemistry*; D002021:Buffers; D002176:Candida albicans / Q000502:physiology*; D002448:Cell Adhesion; D055598:Chemical Phenomena; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D015169:Colony Count, Microbial; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000379:methods; D006801:Humans; D008422:Materials Testing; D010710:Phosphates / Q000737:chemistry; D058105:Polymerization; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D012463:Saliva / Q000502:physiology; D016037:Single-Blind Method; D012965:Sodium Chloride / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014465:Ultrasonics; D017155:Wettability
D000180:Acrylic Resins; D002021:Buffers; D020099:Coated Materials, Biocompatible; D003764:Dental Materials; D010710:Phosphates; D012965:Sodium Chloride; D011138:Polytetrafluoroethylene; D019904:Polymethyl Methacrylate