The dynamic viscoelasticity and plasticizer leachability of tissue conditioners.
OBJECTIVE
Dynamic viscoelasticity is one of the most important characteristics of tissue conditioners. Leaching of plasticizer from tissue conditioners may cause changes in the dynamic viscoelasticity of these materials. The purpose of this study was to determine the dynamic viscoelasticity and plasticizer leachability of commercial tissue conditioners.


METHODS
Five commercial tissue conditioners were used in this study: COE Comfort (CC), Fit Softer (FS), Hydro-Cast (HC), Soft Conditioner (SC) and Visco-Gel (VG). Five specimens of each material were stored in 37°C distilled water. The dynamic viscoelasticity and plasticizer leaching of each specimen were measured at 0, 1, 3, 7 and 14 days after immersion using a dynamic mechanical analyzer and high performance liquid chromatography. Data were analyzed using one-way anova and Student-Newman-Keuls test (α = 0.05).


RESULTS
Significant differences in dynamic viscoelasticity and plasticizer leaching were found among the materials. The dynamic viscoelasticity of all materials increased or decreased significantly with time. Rapid changes in dynamic viscoelasticity were evident on day 1 after water immersion. The material CC recorded the highest level of plasticizer leaching.


CONCLUSIONS
These results suggest that the dynamic viscoelasticity of commercial tissue conditioners is affected by plasticizer leaching. However, these effects are limited.
Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai, Japan. hong@m.tohoku.ac.jp
Guang
G
Hong
Takeshi
T
Maeda
Hiroshi
H
Murata
Keiichi
K
Sasaki
D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid; D003822:Denture Liners; D004548:Elasticity; D008422:Materials Testing; D010968:Plasticizers / Q000737:chemistry*; D014016:Tissue Conditioning, Dental / Q000379:methods*; D014783:Viscosity
D010968:Plasticizers