Ozden N, Ayhan H, Erkut S, Can G, Pişkin E
Department of Prosthetics, Faculty of Dentistry, Ankara University, Turkey.
Dent Mater. 1997 May;13(3):174-8. doi: 10.1016/S0109-5641(97)80120-0.
The main purpose of this study was to demonstrate an increase in the wettability of silicone-based impression materials after coating them with a hydrophilic film in a glow-discharge system.
Two vinyl polysiloxane impression materials, Extrude (Kerr) and Accuflex (GC America Inc.) were used. Impression specimens were treated in a glow-discharge reactor at a radio frequency of 13.56 MHz at different discharge powers (5-20 W) and exposure times (5-60 min). Surface analysis of the specimens was done by FTIR. Surface contact angles were obtained by a captive-bubble method. These results were analyzed by ANOVA and Duncan's Multiple Range test (p < 0.05). The total number of voids on the die stone casts was observed microscopically. Linear dimensional accuracy, detail reproducibility, and surface hardness of the die stone casts were also determined. A Student t-test was performed for statistical analysis of these parameters (p > 0.05).
FTIR spectra indicated that the number of hydroxyl groups on the surfaces increased (p > 0.05) because of the glow-discharge treatment. Contact angle measurements showed an increase (p < 0.05) in surface hydrophilicity. Total void formation in the stone casts decreased. There were no significant differences in the linear dimensional accuracy, detail reproducibility, and hardness, before and after glow-discharge treatment (p > 0.05).
It was concluded that the surface wettability of the impression materials may be increased by plasma deposition, and therefore, the formation of voids was reduced in the stone casts.
