National Dental Assisting Examining Board (NDAEB) Practice Exam

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Prepare for the National Dental Assisting Exam with comprehensive quiz questions, including multiple choice and detailed explanations. Equip yourself for success!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

Which substance is known to be the hardest calcified material in the body?

Dentin
Bone
Cementum
Enamel

The correct answer is: Enamel

Enamel is known to be the hardest calcified material in the human body. This remarkable hardness is primarily due to its high mineral content, primarily hydroxyapatite crystals, which give enamel its strength and durability. As the outermost layer of the tooth, enamel serves to protect the underlying tissues from mechanical forces during chewing as well as from chemical erosion by acids. In contrast, dentin, while also a calcified tissue, is softer than enamel and has a more flexible composition that allows it to absorb stress and provide some cushioning for the enamel. Bone, although hard and has a role in supporting the body, bears a different composition and structure compared to enamel. Cementum, which covers the root of teeth and helps anchor them to the periodontal ligament, is the least hard among these materials. The specific properties and functions of enamel make it uniquely suited for its protective role, which underscores why it is considered the hardest calcified material in the body.