One of the biggest thing that baffles a lot of people is about how to do the lingual tilt. However, the bigger question in this matter isn’t about the how to demonstrate a lingual tilt on a lower posterior tooth prep but rather how you MUST relate your bur to the long axis of the clinical crown. Your bur must be parallel to the long axis of the clinical crown. Any tooth has its own angulation, actually. But this issue about the lingual tilt becomes more important in the lower posterior teeth because these tend to show the most obvious lingual teeth compared from the rest of the teeth.

So you have to drill this into your mind that no matter what tooth you are preparing, always consider the long axis of the clinical crown! Do not be that person that doesn’t pay attention to the long axis of the clinical crown even though it is the most fundamental step in any kind of preparation.

Take a look at this picture, it summarizes the different angulation of each tooth. Naturally, the lower molars are lingually tilted, so the bur should follow that angulation. But how do we effectively see and visualize this angulation on the tooth?

To simplify things, when looking at the buccal and lingual surface from a mesial perspective, notice that the general direction of the clinical crown goes lingual (this is the long axis of the clinical crown). Always visualize that the tooth is tilted in this way and place the bur directly on the center of the occlusal surface. Then look at it from afar, and slowly tilt your bur matching it to the long axis of the clinical crown.

When do I start and end doing the lingual tilt?

After you determined the long axis of the clinical crown and already matched it with the bur angulation, this lingual tilt of the bur should be maintained from the punch cut until the end of the prep. This lingual tilt does not apply on burs alone but also applies to handling of hand instruments as well.

It is very important that the lingual tilt should be maintained and locked in position while doing the whole preparation. Since the lingual angulation is inherently existing on a lower posterior tooth, we must respectfully follow it along the way. This lingual tilt is what’s considered as “straight” for this tooth.

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