**Core Concept**
Local anaesthetics are a class of drugs that temporarily block the transmission of nerve impulses, providing pain relief by preventing the generation and conduction of action potentials. Surface local anaesthetics are applied topically to the skin to achieve this effect.

**Why the Correct Answer is Right**
The correct answer is **C. Dibucaine**. Dibucaine is a potent intravenous local anaesthetic, but it is not typically used as a surface local anaesthetic due to its high potency and potential for systemic toxicity. In contrast, surface local anaesthetics like lidocaine and benzocaine are designed for topical application and have a lower risk of systemic absorption.

**Why Each Wrong Option is Incorrect**
**Option A:** **Lidocaine** is commonly used as a surface local anaesthetic due to its rapid onset and short duration of action. It is often used in conjunction with other agents to enhance its effects.

**Option B:** **Benzocaine** is another surface local anaesthetic that is frequently used in topical formulations, such as sprays and ointments, to provide pain relief for minor skin injuries.

**Option D:** **Tetracaine** is a surface local anaesthetic that is used in some topical formulations, although it is less commonly used than lidocaine or benzocaine.

**Clinical Pearl / High-Yield Fact**
Remember that surface local anaesthetics should be used with caution in patients with certain medical conditions, such as cardiovascular disease or neurological disorders, due to the risk of systemic toxicity.

**Correct Answer: C. Dibucaine is not typically used as a surface local anaesthetic due to its high potency and potential for systemic toxicity.**