Which material is known for its mild abrasive properties and is used for polishing teeth?

Chalk is known for its mild abrasive properties and is commonly used in dental polishing pastes. Its soft nature allows it to effectively remove extrinsic stains from the tooth surface while minimizing the risk of damaging the enamel. The calcium carbonate in chalk provides a gentle polishing effect, making it suitable for use in dental settings where careful attention to enamel preservation is necessary.

Flour of pumice, while also abrasive, is generally coarser compared to chalk and may not be considered as mild. Silex and zirconium silicate are more abrasive materials and are often used for specific purposes or in professional dental equipment rather than for routine tooth polishing. Therefore, chalk is favored in dental hygiene practices for its effectiveness combined with safety for tooth enamel.