INBDE (Integrated National Board Dental Examination) Practice Exam

Setting reaction of dental amalgam proceeds primarily by what?

1. Mercury reaction with Ag on or in the alloy particle

2. Chemical bonding with the tooth

3. Polymerization reaction

4. Hydration process

The correct answer is: Mercury reaction with Ag on or in the alloy particle

The correct answer is A. Setting reaction of dental amalgam primarily proceeds by mercury reacting with silver (Ag) on or in the alloy particle. During the setting reaction, the mercury in the dental amalgam alloy interacts with the silver component in the alloy particles to form the stable silver-mercury (Ag-Hg) phase. This reaction is crucial for the initial setting and hardening of the dental amalgam restoration. Option B, chemical bonding with the tooth, is not correct because the setting reaction of dental amalgam is primarily dependent on the reaction between mercury and the alloy particles, rather than chemical bonding with the tooth structure. Option C, polymerization reaction, is not the correct answer as polymerization is not the primary mechanism involved in the setting reaction of dental amalgam. Polymerization is a process associated with resin-based materials like composite restorations, not dental amalgam. Option D, hydration process, is also incorrect as hydration usually refers to the process of water molecules interacting with certain materials to bring about a chemical change, which is not the primary mechanism in the setting reaction of dental amalgam. The hydration process is more commonly associated with materials like gypsum products rather than dental amalgam.