Effect of the association of nystatin with a tissue conditioner on its ultimate tensile strength.
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.
Urban
Vanessa Migliorini
VM
Department of Dental Materials and Prosthodontics, Araraquara Dental School, São Paulo State University, Araraquara, São Paulo, Brazil. vanurban@yahoo.com
de Souza
Raphael Freitas
RF
Arrais
Cesar Augusto Galvao
CA
Borsato
Karina Tostes
KT
Vaz
Luís Geraldo
LG
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
D000935:Antifungal Agents; D010968:Plasticizers; D009761:Nystatin; D020366:Methylmethacrylate; D003993:Dibutyl Phthalate; D000431:Ethanol