Tips For Taking High-Quality Digital Impressions
Intra-oral scanners are taking off and are on the verge of becoming the new normal. As more of our Doctors integrate them into their practices, we commonly hear the question "What should I be looking out for when I take digital impressions?".
There are many steps a clinician can take to ensure a quality digital impression. Quality controlling your work before it's sent to the lab saves time in the long run and can help avoid headaches. There are three tips we tell all of our clients when they ask what they should be looking out for:
Acquire a sub-marginal line of sight.
Assure ideal margin isolation.
Select Margin Prep Design
1. Acquire a sub-marginal line of sight
Whatever you see in your mirror is what the scanner is going to pick up. Consequently, whatever the scanner picks up, the lab will see. You want to be able to see a .5mm sub-marginal so that the lab technician will be able to identify the margin without question.
Often we receive digital impressions that have not had an adequate job of tissue and moisture control. While the margin is visible, it is not clearly definable. Impression material will hydraulically force tissue and moisture out of the way and travel sub-marginal. Your pre-impression techniques for digital impression must accommodate that same sub-marginal requirement visually.
When sufficient separation between the soft tissue and the margin is not achieved, it can be immediately seen with the first scan. If moisture or tissue is picked up by the scanner and is blocking or inhibiting the margin, we advise that you adjust accordingly and re-scan.
Below is an example of an adequate sub-marginal line of sight.
2. Assure ideal margin isolation.
Digital impression technique is similar to conventional in the fact that margin isolation is crucial. The most effective way to gain a clear digital impression is to prepare a supragingival margin. This is not always possible as often clinical needs dictate subgingival margins, but whenever the situation allows for it, it will aid your digital impression experience.
When subgingival margins are present these retraction strategies work well:
● Using retraction paste such as Expasyl, Traxodent, or 3M Espe Astringent can give you the cleanest line of sight, and usually have hemostatic properties, thus controlling the problem of bleeding.
● Packing cord is an effective means to get the isolation you need, though it does take up some of the space that you need to get a clear visual submarginal.
● Use a soft-tissue laser to remove unhealthy inflamed bleeding tissue and tissue that is impinging on the margin.
Below is an isolated sub-gingival margin.
3. Margin Prep Design
It is best to prep a moderate to heavy chamfer and polish your prep. The chamfer margins allow the milling process to produce the most intimately fitting crown. Avoid feather edge margins, especially when they are deep subgingival. Scanned feather edge margins can make it more difficult for the technician to identify the margins.
Following these three tips will get you on the right path to taking high-quality digital impressions. For more helpful tips and other interesting dental content, subscribe to our mailing list. If you have any questions or want to learn more about this topic, reach out to us at Admin@greatimps.com.
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