Effect of immersion in sodium chloride solution during microwave disinfection on dimensional stability, water sorption, and water solubility of denture base acrylic resin

Abstract

ABSTRACT
Background: Microwave energy has been used as an alternative method for disinfection and sterilization of dental
prosthesis. This study evaluated the influence of immersion in NaCl solution, immersion in water, and in dry air during
microwave disinfection on dimensional stability, water sorption, and water solubility of hot cure, cold cure, and soft
acrylic resin.
Materials and methods: Three types of acrylic resin denture base materials were used in this study: hot cure, cold
cure, and soft acrylic resin material. This study was conducted to evaluate the affect of immersion in NaCl solution,
immersion in water, and in dry air during microwave disinfection on dimensional stability, water sorption, &water
solubility of acrylic resin denture base. Forty-five rectangular specimens were used for testing dimensional stability,
and twenty disks specimens for each type of material were made to test water sorption and water solubility.
Results: results for dimensional stability revealed that all test groups was insignificantly (p>0.05) affected by different
methods of microwave disinfection except HN and SW test groups which were significantly affect (p<0.05). For water
sorption test, the results revealed that only cold cure acrylic resin showed a highly significant difference (p<0.01) for
CW, and CD test group. And finally, for water solubility test show there was no significant difference (p>0.05) for all
test groups.
Conclusion: Dimensional stability could be affected by immersion in NaCl solution when used for hot cure acrylic
resin, while for soft acrylic resin it could be affected when immersed in water during microwave disinfection. Water
sorption for cold cure acrylic resin significantly changed when immersed in water and when placed in dry air during
microwave disinfection.
Keywords: acrylic resin, dimensional stability, water sorption, water solubility, microwave. (J Bagh Coll Dentistry
2010;22(3):46-51).