Dental Impression Materials
Types of impression materials used in dental prosthetics.
Dental impression materials capture the precise details of oral structures for fabricating dental restorations and prosthetics. They are classified as elastic (flexible when set) and non-elastic (rigid when set). Elastic materials include hydrocolloids (alginate and agar) and elastomers (polyvinyl siloxane, polyether, polysulfide, and condensation silicone). Polyvinyl siloxane (PVS) is the most widely used elastomeric impression material due to its excellent detail reproduction, dimensional stability, and ease of use. It is available in various viscosities from light-body (for detail capture) to putty (for bulk support). Polyether materials offer superior hydrophilicity, making them excellent in moist conditions, and they have good dimensional stability. Alginate remains popular for diagnostic models, orthodontic records, and study casts due to its low cost and ease of use, despite its limited accuracy and dimensional instability. With the advent of digital impressions using intraoral scanners, traditional impression material use is decreasing, particularly for single-tooth restorations. However, physical impressions remain relevant for complex prosthetic cases and in practices without digital scanning technology.