The correct answer is Anionic detergents.

Anionic detergents are a class of surfactants that possess a negatively charged head group (anion) and a hydrophobic tail. These detergents are widely used in various cleaning products, including toothpaste. Their effectiveness stems from their ability to reduce the surface tension of water, allowing for better wetting and emulsification of dirt and debris. In toothpaste, anionic detergents such as sodium lauryl sulfate (SLS) act as foaming agents, enhancing the cleaning and refreshing experience. They help to remove plaque and food particles from the teeth, contributing to better oral hygiene. Other types of detergents, while possessing cleaning properties, are not typically included in toothpaste due to various factors including potential irritation or incompatibility with other ingredients. The selection of anionic detergents is often based on their effectiveness, safety profile, and cost-effectiveness.

Non-ionic, cationic, and synthetic detergents, while used in other cleaning applications, are not as commonly found in toothpaste. Their properties may not be as suitable for the specific requirements of oral hygiene formulations or could present adverse effects on the oral mucosa.