Which abrasive is specifically noted as not containing fluoride?

Flour of pumice is known for its fine texture and is specifically utilized in dental applications such as coronal polishing to provide a gentle abrasive effect without incorporating materials like fluoride. This characteristic makes it suitable for polishing procedures where the preservation of tooth structure and minimization of potential fluoride exposure is desired.

In contrast, other types of abrasives mentioned may have different formulations or additional ingredients, which could include fluoride or other compounds. Recognizing this distinction is vital for practitioners who need to choose the right abrasive depending on the specific polishing requirements and patient sensitivities, especially when fluoride might not be appropriate or desired in certain situations.