A very common clinical scenario is the patient who wants to have restorative dentistry done to close black triangles in the esthetic zone. This can be a gratifying but challenging situation. One of the first things to assess is the height of the papilla and how is compares to the adjacent teeth. Do you have papilla symmetry? Or are there varying heights in the esthetic zone? Next is the relative position of the papilla tip to the proposed incisal edge position. Esthetically we like the length of the tooth to be split between the papilla and the contact. If you have this then closing the triangle can be a simple matter of proper prep design and changing the shape of the tooth using the veneer. If you have a short papilla relative to the final tooth length, you will create a long contact when you close the embrasure space, and although most patients find this preferable to the black triangle, it requires creating achievable expectations.
Veneer preparations that include incisal reduction require a decision about lingual margin design. The two most common designs are a butt joint or a lingual wrap design. There are pros and cons to each of these designs and one or the other may be appropriate depending on the parameters of the case. Creating a butt joint margin is what I prepare more commonly these days. This design allows us to have adequate thickness of porcelain at the incisal edge to allow the technician artistic freedom to create incisal translucency and dentinal effects. Wrapping over the incisal edge also creates the ability for the technician to have artistic freedom, so what are the differences.
Preparation designs for porcelain veneers have varied dramatically over the years. We began utilizing them as a conservative alternative to full coverage and strove to do a minimal prep. Then the pendulum swung back the other way and we were doing much more reductive veneer designs. Now we are moving back to thinner and smaller pieces of porcelain, replacing just corners, and even no prep restorations.
I’ve polished up a presentation tonight that I will be giving tomorrow in Bellevue Washington on Anterior Esthetic Techniques & Materials. One of the concepts we will be looking at is incisal reduction as part of a veneer prep, when do we do it and why? Another way to look at this is when would we not need to create incisal reduction. If we are placing a veneer simply to correct damaged labial enamel on a tooth that has the correct length, incisal edge position, contour and we have underlying dentin that will create exquisite esthetics the tooth can be prepared without incisal reduction.
Recently I received a series of clinical photographs with a question, “What should I do to close the gingival embrasures?” It’s a common question and comes down to preparation design. We close gingival embrasures (or try to) routinely with direct composite. You all know the routine, you place the composite, do some finishing and then it is time to check with an explorer and floss. Sure enough there is a catch at the gingival, so you get out the mosquito diamond or finishing bur and get to work. Several passes later with your explorer it feels as smooth as silk, you sit back and stare at an open gingival embrasure. Ok, maybe this has never happened to you, it happened to me and it is the same issue our technicians face.