A high-quality impression is the foundation of a successful case. Whether for a submission or a revision, accurate impressions are vital to ensuring that treatment is effective and time-wasting delays are avoided. We recently determined that 3 basic issues are accounting for over 75% of all the bad impressions that we receive. Here are the issues, and how to correct them.
Issue #1: Double impression in 2-step material
The most common problem that we find is a double impression, which usually happens during a 2-step impression.
The easiest solution is to switch to a simpler, more reliable 1-step impression material, such as Sultan Genie VPS. We've prepared a video and a printed guide for this type of material.
If you prefer the 2-step impression process, that's okay too. Just keep an eye out for double impressions. Remember to cover the putty with a plastic sheet when you take the first impression, and to take your second impression before the first one has fully set. We have a video and printed guide for this type of impression as well.
Issue #2: Material not fully set
Our second-most common issue is material that hasn't fully set before being removed. There are two simple things you can do to prevent this problem:
- Set a timer and make sure to follow the directions for your material exactly.
- Discard the first 1 inch of material that comes out of every new mixing tip.
Issue #3: Posterior distortion
The final big issue is distortion of the most distal teeth in the impression. It can be hard to see back there, and sometimes the posterior teeth get shortchanged. There are a couple of ways to avoid this problem:
- Make sure that you're using a correctly-sized tray. It should extend past the last tooth in the arch without touching the gums.
- Before inserting the tray containing light body, add some light body directly to the occlusal and distal portion of the last tooth in the arch, ensuring that the last tooth is completely covered with material.
We hope this helps. Look for these issues before you send your impressions in, and you could save yourself & your patient the hassle of taking new impressions.
More Helpful Tips:
- Make sure the tray is not too small and fits your patient well. If the teeth are touching the edges of the tray, the tray is too small.
- Use plenty of PVS material. It's better to have too much than too little.
- Remove all engagers prior to taking the impression. We need impressions free of engagers to make accurate molds.
- Fill in deep undercuts with wax. This will allow you to remove the impression material cleanly without creating tears or distortions.
We hope this helps. Looks for these issues before you send your impressions in, and you could save yourself and your patient the hassle of taking new impressions.