When doctors send dental work to us, they of course trust us on receiving nice work finally. Indeed, we make a lot of beautiful big dental cases every day, but at the same time, we need your good impressions with good preps. Here we use some real case examples and give 7 advises:
1. Please prepare teeth before oral scanning or taking impressions (unless you need non-prep veneers or diagnostic wax-up). Please do not ask us to prepare teeth in our lab, because you could have big problems with fitting.

teeth without preparation
2. Please try not to leave undercuts after preparing teeth, or at least not big undercuts. In many situations, doctors ask for bridges, but they send cases with very big undercuts. If we just block so many big undercuts, doctors may find the crowns very loose (for easier fitting). And patients could suffer from food trap over time. This could also cause gum infection.

big undercut dental preps
3. Please prepare more of teeth, so there is about 1.5mm space between teeth. We also need space for the occlusion (1.5mm). If doctors only prepare little teeth, there is no space for making details such as translucency and more color blending on the incisor.

preps without enough space
4. Please prepare teeth referring to the arch of jaw, so we can align teeth with crowns. Let’s take an example of the tooth in the picture below. The tooth (red arrow) is very bulky. Doctor could prepare more towards palatal, so we can try to make the tooth less bulky, and align is with other teeth.

full arch dental work
5. Please take care of the bite. Let’s look at the example below. The occlusal space is way too big. We could not decide the patient’s bite, so we suggest making a temporary bridge first. With temporary bridges, doctors can make adjustments for correct bite. Please note wrong bite could break crowns and bridges easily.

wrong bite relationship
6. If gum lines of the crowns have to be symmetrical (especially for upper front teeth), please let us know before production. Actually, it is best that you make symmetrical gum lines through surgical operations. If we do that only through making crowns, there could be food trap over time.

unsymmetrical gum lines
7. Please send us clear scans with clear margins. Before oral scanning or taking impressions, please clean blood and saliva first. With clear margins, you will find our fitting is perfect!

dental scans with blur margins