What is true about dentine?

Dentine is a vital component of tooth structure that plays a significant role in the overall health and function of teeth. One of its primary characteristics is that it contains microscopic tubules that communicate with the pulp of the tooth. These tubules allow stimuli such as temperature changes and pressure to reach the nerve endings in the pulp, which is why dentine is associated with sensations of pain and sensitivity.

This sensitivity is particularly important in clinical dentistry, as it influences the diagnosis and management of dental conditions, including caries and pulpitis. Understanding the role of dentine in sensation can help dental professionals address patient concerns regarding discomfort or sensitivity during procedures or in response to certain foods.

Other statements about dentine do not hold true: it is not the outermost layer of the tooth—that would be enamel. Additionally, dentine is present not only in primary teeth but also in permanent teeth. Therefore, option B accurately reflects the unique property of dentine regarding pain and sensitivity.