What should be the relationship of the crown margin to the alveolar crest to preserve biological width?

The correct relationship of the crown margin to the alveolar crest to preserve biological width is to maintain it 2mm above the crest. Biological width refers to the space on the tooth surface that comprises the junctional epithelium and the connective tissue attachment. It is crucial to respect this distance to avoid damaging the periodontal attachment, which can lead to inflammation or attachment loss.

When the crown margin is positioned at an appropriate distance of 2mm above the alveolar crest, it ensures that there is enough space for the natural biological processes to occur without interference. If the crown margin were placed at a lesser distance (like 1mm or flush with the crest), it could encroach on the biological width, potentially resulting in periodontal problems, discomfort, and compromised tooth retention.

Therefore, positioning the crown margin 2mm above the alveolar crest is essential for maintaining periodontal health and ensuring that the supportive structures around the teeth remain intact and functional.