Taking an impression is one of the most important procedures in dentistry and it is critical to achieve a superior restoration. We need an excellent “foundation” on which to build. We have put together a list of tips to help you take a great impression, which will ensure the best restoration possible.
If the tray can be easily flexed with finger pressure, the impression material will likely flex during setting and yield a distorted impression.
Properly constructed custom trays help take impressions with over five times more dimensional accuracy than stock trays. Note: Custom trays should be made at least a day in advance, since most tray acrylic undergoes shrink polymerization within that period of time.
With adhesive, the polymerization shrinkage is toward the tray instead of toward the center of the mass.
With the fast set, the wash is already polymerizing before the tray is even leaded, causing them to set at different rates.
Sulfur found on Latex gloves inhibits the set of many impression material. Sulfur contamination can be avoided by: 1) remove gloves and wash hands before molding putty, 2) use vinyl gloves, 3) use vinyl over-gloves and 4) don’t touch the teeth with the gloves.
The extra minute helps prevent tearing of the margins during removal.
Firm, consistent pressure needs to be maintained after placement by a trained hand.
We will disinfect here and the products that we use in the lab may have an adverse reaction to the
products you use in the office. Simply rinse the impression with cold water immediately and place in the bio-hazard bag.
Expired impression material will often function abnormally and will not set properly.
Air bubbles can be formed when the syringe tip is in the open and lead to voids in the margin area.
This allows us to see the entire arch of the opposing teeth and how they fit together, allowing for a better restoration.
If the tray is loaded too far in advance, the material will begin setting and force the wash material away from the margins.
These techniques will make it easier to keep impression material away from the soft palate.
Click the images to view them full size.