Tearing at the Margin

Insufficient retraction +

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

Inhibition of setting due to use of acidic retraction materials/hemostatic agents like aluminum or ferric salts +

Thoroughly rinse preparation with water and dry before taking the impression.

Smear layer from custom temporary, provisional cements (acrylics) or core build-up present +

Smear layers from acrylates (e.g. core build-up or temporary materials) can inhibit the setting of impression materials. When core build-up and final impression are made in one appointment:

• Be sure to remove the smear layer completely prior to impression taking with alcohol/by polishing. Check surrounding teeth and tissue for any residue. When the temporary and final impressions are made in one appointment:
• Fabricate the provisional after taking the final impression or remove the air-inhibited layer on the exposed preparation with alcohol before taking the final impression.
• Do not use impressions already used to fabricate the provisional for subsequent precision impression taking.
• If a temporary is removed prior to impression taking: Remove all residues of cement and clean the abutment tooth. In case of a core build-up remove the air-inhibition layer on the exposed preparation with alcohol before taking the final impression.

Inadequately mixed materials +

Bleed cartridge before applying the mix tip to ensure even dispensing. Then use the mix tips recommended by the manufacturer and dispense a pea-sized amount onto a mix pad prior to use.

Premature removal of the impression +

Follow manufacturer´s instructions for intra-oral setting time and make sure that the impression material has completely set before removal. Store impression material at room temperature. Usually, times given in the manufacturer’s instructions for use are valid for a storage temperature of 23 °C/74 °F. 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.

Inhibition of setting of VPS impression materials due to contact with sulfur from latex gloves +

Use gloves which do not contain traces of sulfur, e.g. nitrile gloves.

Inhibition of setting of VPS impression materials due to contact with sulfur from latex gloves +

Use gloves which do not contain traces of sulfur, e.g. nitrile gloves.

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.

Expired impression material +

Do not use expired impression material. Follow defined storage conditions for materials given in the instructions for use for full shelf life.