A great impression can facilitate superb dental work or it can present unintended problems down the road. The end result depends on your ability to troubleshoot issues that may occur and communicate your intentions with the dental lab.
Tips for a Consistently Great Impression
One of the most important steps you must take for an amazing impression is maintaining a topography difference between the tissue and preparation. Ensure impression material can flow between the surrounding gingival tissues and the prepared tooth’s margin.
This single step will guarantee the stone model is far more successful. A visually gorgeous prep will pour ideally if you use either a cord retraction or prep design that isn’t flush with the tissue.
Additionally, remember that results you believe look great intraorally may be challenging for the lab. You have to find that sweet spot between very precise and too precise. For an all-ceramic restoration, do not assume a ‘cowboy hat’ fragile shoulder can be replicated in the lab.
Another issue relates to pulls and bubbles. These appear when the impression distorts before it can set or a bubble shows up because of improper wash use. In this case, the lab tech can’t tell where the restoration should end. The only way to avoid the latter problem is by examining continuity closely and utilizing a material viscous enough to prevent pulls while it sets.
Finally, though you always want to be as conservative as possible, you shouldn’t attempt to preserve small toothbrush abrasions (abfractions). This is also true of undercuts, because what happens is the lab cannot create a fit tight enough to keep out bacteria. It simply isn’t possible to fill the divet with ceramic in this case.
What tips do you have for perfect impressions the lab will love? Please let us know in the comments!