Tuesday, April 2, 2013
Direct composite restorations are a great option for a number of anterior cases including closing diastemas which can be a quick way to change an entire smile and improve a patient's confidence.
Anterior composite cases call for lifelike esthetics, and I find that with careful planning, proper shade matching, and a quick mockup as my guide, these cases can become huge successes for a practice and especially for patients.
Getting the shade match
My first step when working on any anterior composite case is to select a tooth shade. When matching the shade, it’s important to keep in mind that the middle of the shade tab and the middle of the tooth is where the body shade should come from.
But while this gives me a general assessment of color, I truly cannot determine if the shade is correct without a direct mock-up. When restoring a class IV restoration, the dentin and enamel layers will need to be reconstructed so there will need to be at a very minimum 2 shades, and depending on how complex realistic you want to make the shading, up to 5 shades can be involved in the restoration.
The important thing to remember is dentin is always richer in chroma than enamel. This means if you determine your final body shade to be A1, then your dentin should really be an A2.
Different manufacturers try to simplify color selection by creating A1 enamel, A1 dentin and translucent incisal choices. While this may work in some circumstances, it is rare that I prep a tooth and see the enamel and dentin being different opacities of the same shade. Instead, what we usually see in nature is dentin richer in chroma and more opaque than the enamel.
So, the best way to demystify the color problem is to create a quick mockup. The mockup is key to determining the thickness I will need to use for each shade in the restoration, and creating a mockup also allows the corrections to be made and visualized before commencing with the final restoration.
I truly cannot work without a mockup, and once it’s created, I snap a quick photo to make sure the color and contour are good building blocks for my final restoration.
Figure 1: A quick mockup is created to evaluate color selection and verify midline and contours.
Approaching the Diastema
While I try to use the same shade matching approach to all anterior composite cases, the workflow is different for each type of restoration. For diastemas there usually is little prep work required, and once I have a mockup I like, placing and finishing the final composite restoration is fairly straightforward.
For diastemas that are about 2 mm or less, an enamel shade of composite will usually be the only shade you need, but diastemas that are larger may require a dentin shade with an overlying enamel shade.
When the shades have been selected, the next step is the mockup which will serve as a guide for the final restoration. When creating the mockup for a composite diastema case, I like to simultaneously add to the mesial of both teeth to ensure my midline is straight and the widths of the teeth are the same. A metal matrix can be used to make sure there is a small separation between the teeth.
Figure 2: The mesial half of diastema is completed on tooth #9 against the mesial half mockup on tooth #8.
Once cured, I evaluate for color, midline and contours. If I like it, I then will very carefully “pop” off of the mesial increment of a tooth and leave the mockup on the other tooth. This will now be my guide to which I can build the half of my diastema. Having a mockup in place makes it easier to know exactly where to build the other tooth instead of just visualizing.
Tooth Preparation
If there are any aspects of the tooth that need recontouring that should be done ahead of time. Otherwise, it is really unnecessary to do any tooth preparation for a composite diastema closure. However, I do like to use a fine pumice to clean the entire facial of the tooth, and I place Tapetrix over the mockup to prevent bonding to it. I then etch the enamel for 60 seconds and place my adhesive bonding agent and cure.
Figure 3: Tooth #8 mesial half completed restoration with final polish.
Placing the Composite
Now I build the mesio-facial aspect of one tooth and do the contouring. While doing this it’s important be sure to blend the composite onto the facial surface. I like to use a gold, extra-thin interproximal carver to do my sculpting. A flat sable brush also can be used to feather the composite onto the facial surface.
Light cure in between the increments of composite. It is important to emphasize that we are only building the mesio-facial half of the restoration. Now I can “pop” off the last mockup piece and place a clear matrix against the tooth I am working on. Next I place the composite to add to the mesio-lingual half of the diastema and pull the matrix through towards the facial. This ensures there will be no voids.
Finishing and Polishing
I use a coarse disk to contour the facial surface first, and check from the incisal view to make sure the facial planes are the same. I then use polishing strips to get a nice smooth interproximal surface. I finish all the polishing with a sequence of disks and some polishing paste if a high luster is desired.
Finally I repeat the procedure for the mesial half of the other tooth to complete the diastema closure.
Figure 4: A before image of another diastema case which was well suited for this clinical approach.
Figure 5: The result after completing the case using one shade of enamel composite and the same technique.
Figure 6: A before image of another diastema case which also was well suited for this clinical approach.
Figure 7: The result after completing the case using one shade of enamel composite and the same technique.
The key to success with this direct restorative approach for diastemas is to match the shade and then complete a mockup to make sure the match is correct and the contours look natural. With the mockup as a guide it’s much easier to create an esthetic restoration your patients will be thrilled with.