Incomplete Reproduction of Margins

Insufficient retraction +

Retract gingival tissue to entirely capture the prepared area. Retraction cords as well as retraction pasts are suitable.

Blood and saliva contamination +

Rinse and dry the prepared area and stop any bleeding by using appropriate retraction technique and a hemostatic agent. Liquids or pastes based on aluminum chloride, aluminum sulfate, or iron sulfate are suitable hemostatic agents.

Working time exceeded, flowability already impaired +

Select material with sufficient working time and pay attention to storage temperature. Working times are reduced due to higher temperatures of the product, while intra-oral setting times might be longer if the temperature of the product is lower.

Inadequate coverage of marginal area with light body impression material +

Use wash material liberally on preparation and abutments.

• When using 1-step technique: Avoid high viscosity contrast between tray and wash material. Especially, when using putty materials combine them with a high viscosity wash material. In general, follow manufacturers’ recommendations for material combinations.
• When using 2-step technique: Carve tray material before applying wash material oruse foil as spacer.

Impression material has low tear resistance +

Let the material completely set prior to removal of the impression and use impression material with sufficient tear resistance.