Dental Alginate Impressions

Excerpt

Impression materials are classified as either elastic or non-elastic based on mechanical properties. Elastic materials are capable of stretching, compressing, and recovering after deformation. Elastic materials comprise reversible and irreversible hydrocolloids, addition and condensation silicones, polysulfides, and polyether. Non-elastic or rigid impression materials include impression compounds, zinc oxide eugenol, and impression waxes.

Hydrocolloids were the first elastic materials used in the dental field. Hydrocolloids produce an imprint providing high-definition details despite undercuts. While the impressions deform upon removal, they later adapt to the original shape due to their elastic properties. Alginate is an elastic, irreversible hydrocolloid that offers lower costs, improved patient tolerance, ease of manipulation, reduced execution times, and the possibility of obtaining a detailed impression in a single step.