National Dental Examining Board of Canada (NDEB) Practice Exam

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Master your National Dental Examining Board of Canada (NDEB) exams with our comprehensive practice guide. Achieve excellence in your dental certification with expertly crafted questions and detailed explanations.

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How is the Therapeutic index calculated?

  1. ED50/LD50

  2. LD50/ED50

  3. ED95/LD95

  4. LD95/ED95

The correct answer is: LD50/ED50

The Therapeutic index is a measure of the safety of a drug. It is calculated by dividing the lethal dose (LD50) by the effective dose (ED50). This ratio helps determine the range of doses in which a drug is safe and effective for use. Option A and C are incorrect because they reverse the order of the ratio, which would result in a meaningless calculation. Option D also reverses the order and includes LD95 and ED95, which are not commonly used measurements in drug research.