Which material is commonly used for making dental impressions?

• A. Composite resin
• B. Alginate
• C. Amalgam
• D. Dental wax

Answer: (B)

The material commonly used for making dental impressions is alginate. Alginate is a hydrocolloid material derived from seaweed, known for its ability to capture fine details of the oral structures. It is widely favored in dentistry due to its ease of use, quick setting time, and ability to produce accurate impressions with excellent detail reproduction.

Alginate impressions are generally made for preliminary casts and for creating study models. They are also used because they are economical and can be mixed as needed to create the desired consistency. The material also provides sufficient flexibility, allowing for easy removal from undercuts in the teeth or oral tissues.

In contrast, composite resins are primarily used for direct restorations and not for capturing impressions of the oral cavity. Amalgam, which is a material used for dental fillings, would not serve as an impression material either, given its solid form once set, which would not lend itself to capturing the nuances of oral anatomy. Dental wax, while capable of making functional impressions (like bite registrations), is not as commonly used for detailed impressions of the teeth and gums as alginate. This emphasizes alginate's unique properties that make it the standard choice for dental impressions.