When preparing a chamfer, what concern must be taken into account?

The concern of an unsupported lip of enamel is critical when preparing a chamfer in prosthetic dentistry. A chamfer preparation typically involves creating a smooth, rounded margin that allows the restoration to achieve proper adaptation and seal. If there is an unsupported lip of enamel, it can lead to fracture or chipping of the enamel, ultimately compromising the integrity of the tooth structure.

Moreover, this situation can create difficulties in the seating of the restoration and may prevent an effective bond between the tooth and the material used for the restoration. Preserving the enamel margin is essential for the longevity and success of the dental work. Proper techniques during the preparation can help ensure that the enamel is adequately supported, which provides a stable base for the final restoration and maintains the strength of the natural tooth structure.

In contrast, considerations like overcontouring, retention of the material, and alignment with occlusion are also important but relate to different aspects of the prosthetic design and functionality rather than directly addressing the structural integrity of the enamel margin.