title: Effect of the association of nystatin with a tissue conditioner on its ultimate tensile strength.
abstract: OBJECTIVE
  This study evaluated the ultimate tensile strength of a tissue conditioner without nystatin incorporation (GI-control group) and the same tissue conditioner modified by the addition of nystatin in two concentrations: GII-500,000 International Units (U) and GIII-1,000,000 U, in which each milligram of the medicament corresponded to 6079 U.
  
  
  METHODS
  Dumbbell-shaped specimens (N= 7) with a central cross-sectional area of 33 x 6 x 3 mm were produced for the three experimental groups. After polymerization following manufacturer's instructions, specimens were immersed in distilled water at 37 degrees C for either 24 hours or 7 days and then tested in tension in the MTS 810 at 40 mm/minute. Data were analyzed by two-way ANOVA followed by Tukey's test, at 95% level of confidence.
  
  
  RESULTS
  The means (force-grams (gf) +/- standard deviation) of the ultimate tensile strength were: GI-634.29 +/- 122.80; GII-561.92 +/- 133.56; and GIII-547.30 +/- 73.47 for 24-hour storage, and GI-536.68 +/- 54.71; GII-467.50 +/- 143.51; and GIII-500.62 +/- 159.76 for 7-day storage. There were no statistically significant differences among the three experimental groups (p > 0.05). The ultimate tensile strength means of all experimental groups after 7 days were significantly lower than those observed after 24 hours (p= 0.04).
  
  
  CONCLUSIONS
  The results of this study suggest that the addition of nystatin into the tissue conditioner investigated in concentrations below 1,000,000 U did not affect its ultimate tensile strength.
authors.affiliation: Department of Dental Materials and Prosthodontics, Araraquara Dental School, São Paulo State University, Araraquara, São Paulo, Brazil. vanurban@yahoo.com
authors.forename: Vanessa Migliorini
authors.initials: VM
authors.lastname: Urban
authors.forename: Raphael Freitas
authors.initials: RF
authors.lastname: de Souza
authors.forename: Cesar Augusto Galvao
authors.initials: CA
authors.lastname: Arrais
authors.forename: Karina Tostes
authors.initials: KT
authors.lastname: Borsato
authors.forename: Luís Geraldo
authors.initials: LG
authors.lastname: Vaz
mesh_terms: D000704:Analysis of Variance; D000935:Antifungal Agents / Q000008:administration & dosage*; D002180:Candidiasis, Oral / Q000517:prevention & control; D003799:Dental Stress Analysis; D003822:Denture Liners; D003993:Dibutyl Phthalate; D004356:Drug Storage; D000431:Ethanol; D008422:Materials Testing; D020366:Methylmethacrylate; D009761:Nystatin / Q000008:administration & dosage*; D010968:Plasticizers; D013282:Stomatitis, Denture / Q000517:prevention & control; D013718:Tensile Strength; D013997:Time Factors; D014016:Tissue Conditioning, Dental
chemical_list: D000935:Antifungal Agents; D010968:Plasticizers; D009761:Nystatin; D020366:Methylmethacrylate; D003993:Dibutyl Phthalate; D000431:Ethanol