Areas where the impression material fails to capture the complete tooth anatomy or gum line.
This usually occurs due to an insufficient amount of impression material in the tray.
Ensure that there is ample material in the tray when taking impressions. It is better to have excess material than too little.
Bubbles
Air bubbles present within the impression.
Bubbles can form when the mixing tip is lifted out of the impression material during dispensing or due to excessive saliva in the patient's mouth.
Keep the mixing tip submerged in the impression material during use and remove any excess saliva from the patient's mouth before taking the impression.
Thin Walls
The impression captures most of the tooth anatomy, but the scan of the material is incomplete or distorted due to thin material walls.
Caused by insufficient material, using trays that are too small, or pressing the tray too deeply into the mouth.
Use enough material, ensure the tray fits properly and extends beyond the most distal tooth, and avoid pressing the tray too hard against the teeth.
Double Imprints
Impressions that show duplicate gum lines or tooth imprints.
Movement of the tray during the setting process or incorrect initial impression steps, such as not using a plastic sheet in two-step impressions.
Instruct patients to keep still during impressions and use a plastic sheet over the first-step impression when using two-step procedures.
Pulls
The impression shows a "pulled" effect around the gingival margins.
Setting of the impression material before it is fully placed in the mouth or removal of the tray before the material has set.
Quickly place the tray in the mouth after dispensing the material and leave it in place slightly longer than the recommended time.
Tears
Tearing of the impression material during removal, affecting the accuracy of the impression.
Occurs when the material catches on undercuts or black triangles, or if the material has not fully set.
Block out undercuts with wax and ensure the material is fully set before tray removal by extending the set time.
Improper 2-Step Impression
The second step of the impression does not bond properly to the first, indicated by only seeing the top layer of material.
Use of incompatible types of heavy and light body materials.
Verify the compatibility of heavy and light body materials before use.
Insufficient Material
Not enough material used to accurately capture the desired anatomy.
Mismeasurement of material needed relative to the tray size.
It's preferable to use more material than needed to ensure all details are captured accurately.