This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': 'A 24 year old male presents to OPD with sensitivity to cold water. On intraoral examination, 46 is carious and dentist decides to restore the teeth with amalgam restorative material with zinc phosphate base. Which of the following statements  are true regarding manipulation of this cement? \nSelect and explain. \nA. Spatulate each increment of powder for 15 to 20 seconds before adding another increment, B. Mixing should be completed within 1.5 to 2 minutes, C. Most of the area of the mixing slab should be used to dissipate heat, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Mixing of Zinc Phosphate Cement\nMixing of this cement should be initiated by incorporating the smallest portion of powder using a thin spatula and brisk\xa0spatulation. Most\xa0of\xa0the\xa0area\xa0of\xa0the\xa0mixing\xa0slab\xa0should\xa0be used to dissipate heat. A good rule to follow is to spatulate each increment of powder for 15 to 20 seconds before adding another\xa0increment,\xa0and\xa0all\xa0mixing\xa0should\xa0be\xa0completed within 1.5 to 2 minutes. After the powder is completely incorporated and a creamy mixture has been created, the cement is\xa0drawn\xa0across\xa0the\xa0slab\xa0and\xa0the\xa0flat\xa0blade\xa0of\xa0the\xa0mixing spatula contacts the mixture and is slowly drawn away. If a string of cement can be lifted 12\xa0mm (12\xa0 inch) to 19 mm (~ 34 inch) before separating from the spatula, the cement is considered fluid enough for cementing a prosthesis. If\xa0the\xa0string\xa0exceeds\xa019 mm,\xa0the\xa0 cement\xa0is\xa0too\xa0viscous\xa0for proper\xa0seating\xa0of\xa0prostheses and\xa0another mixture should be made. After the prosthesis is coated with the cement and is seated, it should be held under pressure until the cement sets. The field of operation should be kept dry during the entire seating procedure.', 'role': 'assistant'}]