**Question:** The complication of using airotor at 30,000 rpm for impacted molar is:

A. Pulpal injury
B. Gingival recession
C. Tooth fracture
D. Oral mucosal injury

**Core Concept:** Airotor is a dental instrument used for various dental procedures, particularly for the removal of impacted molars. Its rotational speed determines the force and precision of the tool. 30,000 rpm (revolutions per minute) is a relatively high speed that might increase the risk of complications.

**Why the Correct Answer is Right:** Using a dental airotor at a speed of 30,000 rpm for an impacted molar can lead to pulpal injury (Option A). The high speed of the airotor can cause excessive heat generation due to friction between the instrument and the tooth, leading to thermal necrosis of the dental pulp and potential irreversible pulpitis or pulp necrosis.

**Why Each Wrong Option is Incorrect:**

- Gingival recession (Option B) is not directly related to the airotor's rotational speed. It is caused by gingival tissue erosion due to prolonged use of the instrument and improper technique.
- Tooth fracture (Option C) can occur during dental procedures, but not specifically due to the rotational speed of the airotor. Factors like the tooth condition, operator's skill, and excessive force applied during the procedure are more relevant for tooth fracture.
- Oral mucosal injury (Option D) can occur during dental procedures, but it is not directly linked to the rotational speed of the airotor. Inadequate technique, operator inexperience, or excessive force applied during the procedure are more likely causes.

**Clinical Pearl:** When using a dental airotor for dental procedures, especially on impacted molars, it is crucial to maintain appropriate technique and apply minimal force to minimize complications like pulpal injury and other potential harm to adjacent tissues. Choose a suitable speed for the specific procedure, ensuring the balance between effectiveness and patient safety.