Closing 'Black Triangles'

Closing black triangles is a common request among esthetically aware patients. This particular patient wanted porcelain veneers to cover the mottled appearance, cracks and spaces. She also has class III carious lesions between the laterals and centrals that have not been treated.

If the embrasures were not open between the lateral and centrals and the decay were not present, preparations for veneers would be very conservative. However, in order to take care of the decay and then close the black triangles, the preparations become more aggressive.

In order to close a diastema or black triangle and not have a restoration with abnormal contours or overhangs the preparation must allow for a normal emergence profile of the final restoration. That means that the margin of the preparation must extend onto the palatal aspect of the teeth involved. Carrying the margins slightly subgingival and past the palatal aspect of the papilla allows the ceramist to develop normal contours. Without that room, the resulting restoration will have abnormal contours that are hard to clean, may trap food and not be esthetically ideal.

In this case, the decay added to the extent of the preparations, but the preps on the facial are still in enamel. We always would like to remove as little tooth structure as possible, yet sometimes being too conservative can create problems.