Article information
Year 2019 Volume 69 Issue 2 Page 175-184
Title:
Effect of Ultrasonic Treatment on The Leachable Monomer Content from A Self Cured Acrylic Hard Denture Reline Material
Keyword(s):
High pressure liquid chromatography, Leached monomer, Acrylic resin, Hard reline, Ultrasonic
Abstract:
The aim of this study was to compare the amount of leachable monomer of a hard reline acrylic resin,
after residual monomer reduction treatments, in water immersion at various times. Twenty-four specimens of an
auto-polymerized acrylic hard denture reline material (Unifast Trad Pink) were prepared and divided into four groups
(n= 6): Group 1 control, untreated; Group 2 water immersion at 50oC for 1 hour; Group 3 and 4 water and 30 %
ethanol solution immersion at 50oC in ultrasonic bath for 5 minutes, respectively. Specimens were immersed in water 37oC. Water samples were taken from each immersion solution at the periods of 1, 3, and 24h and also at 3,
7 days. The water samples containing leachable monomer were analyzed using HPLC following ISO 20795-1(2013).
The data were analyzed by Two-way ANOVA, One-way and Dunnett’s T3 comparison test. All tests were performed
at a confidence level of 95 %. The result showed that the amount of leached methyl methacrylate (MMA) in Group
2, 3 and 4 was significantly lower than that of Group 1 (p<0.05) but Group 1 and 2 was not significantly different
in day 7 (p>0.05) and the amount of leached MMA in Group 1 and 2 was significantly higher than that of Group 4
(p<0.05) but there was not significantly different from that of Group 3 (p>0.05). In conclusion, water or 30 % ethanol
solution immersion in ultrasonic post polymerization treatment at 50oC for 5 minutes of a hard reline acrylic resin
significantly reduced the amount of leached MMA, which was better or similar than water immersion at 50oC for 1
hour and this method is more effective in clinical situation than presently recommended methods because of only 5
minutes immersion time.