Improving dimensional stability of dental amalgam by using Nano Zinc Oxide.

To investigate the dimensional stability of dental amalgam after the incorporation of zinc oxide nano powder. The experimental study was conducted at the Hamdard University Dental Hospital and the Pakistan Council of Scientific and Industrial Research laboratories, Karachi, from January to June, 2018. Direct precipitation method was used in which analytical grade sodium hydroxide and zinc nitrate hex hydrate were used without any further purification. The sample was randomly divided into two groups. The control group A had 0 wt.% of nano zinc oxide, while the experimental group was further divided into 2 subgroups, with group B containing samples having 3 wt.% and group C 5 wt.% of nano zinc oxide. Delayed expansion was checked using electron micrometer. Data was analysed using SPSS 22. Of the 180 samples, there were 90(50%) in control group A, and 45(25%) each in experimental groups B and C. Subgroup B showed significantly more linear expansion than subgroup C. Subgroups B and C achieved their entire linear expansion after 24 hours. There was improvement in the dimensional stability of dental amalgam after the incorporation of nano particles of zinc oxide.