How many roots are present in a first premolar?

The first premolar typically has a single root. In both primary and permanent dentitions, premolars are generally characterized by their single-root structure. However, it's important to note that while primary dentition does not have premolars—since the primary dentition consists of incisors and canines, followed by molars—this particular question seems to focus on the anatomy of teeth rather than their existence in primary dentition.

The understanding that a first premolar has a single root is critical in dental anatomy, aiding in the identification and treatment of dental conditions. Moreover, in permanent dentition, the first premolar usually has one root, but it sometimes may exhibit two canals within that root. It's beneficial for dental nurses to have a thorough knowledge of these anatomical structures for effective patient care and treatment planning.

Therefore, while the response regarding the absence of roots in primary dentition is contextually valid, the anatomy of a first premolar in the context of permanent dentition is accurately described by the presence of a single root.