This is the fourth in a series of articles on managing open interdental spaces, diastemas or black triangles by using a convex restorative form. In Part 1, I addressed the interproximal gingival margin location relative to the initial sulcus depth, Part 2 focused on the interdental margin location relative to the interdental contact, and Part 3 focused on proper provisionalization. Here in Part 4 I will discuss the essential communication that needs to occur with the technician to predictably close open spaces with the correct restorative contours and position the gingival aspect of the contact at the correct height relative to the desired papilla height.
In Part 1, I discussed the importance of placing the interproximal gingival finish line at the correct depth in the sulcus. This is done to create enough running room for the convex contour of the restoration which needs to be established to decrease the volume of space between teeth and influence the papilla height. The technician will not know where this finish line is placed relative to the desired interdental contact, so this information will need to be communicated to the lab.
After final tooth preparation, the clinician takes a final impression from which the technician pours a solid stone cast. This solid cast represents not only the teeth, but also the gingival contours. To get an accurate impression of the teeth, gingival retraction is required. The papilla is displaced and is blunted during the retraction procedure. This results in distortion of the gingival tissue on the cast relative to the optimal soft tissue position that is desired.
The technician does not have a clear physical or visual reference of the ideal papilla height and therefore does not know where to place the gingival extent of the interdental contact which needs to be established. The technician also does not know where the bone is relative to the desired contact and does not know the position of the finish line relative to the initial sulcus depth. Therefore, it is essential for the clinician to communicate to the technician the distance of the interproximal margin location to the interdental contact. The clinician needs to determine how much the papilla may increase in height relative to the preparation margin.
If this distance is not communicated to the technician, the technician will commonly make a longer interdental contact (extending too apical), resulting in a possible impingement of the papilla. Technicians fear leaving the contact too far incisal which may result in a black triangle. If the contact is made too long, the clinician would need to reshape the interproximal areas of the restorations, to move the contact more incisal.
This adjustment is accomplished chairside. The challenge the clinician will have is once the provisionals are removed from the teeth, the soft tissue, including the papilla, begins to change (slump). If the gingival aspect of the interdental contact is too far incisal, the restorations would need to be returned to the laboratory to add additional ceramic to make the contact longer.
Additional communication with the technician can be achieved by sending:
- A preoperative cast.
- Preoperative photographs.
- A photograph after tooth preparation but before gingival retraction. This will show how much the papilla slumps relative to the interproximal finish line of the preparation.
- A photograph of the provisional restorations after the papilla his creeped incisally. This can be used to compare any differences with the preoperative photograph.
- Casts of the provisionals after the optimal papilla height has been achieved.
It is critical to have effective communication with the technician to predictably close interdental spaces with restorative contours. It is essential for the clinician to manage the papilla correctly during the provisionalization of the teeth. In Part 5, I will discuss insertion of the veneers.
Robert Winter, D.D.S., is a member of Spear Resident Faculty.