The other issue, and this where things get really tough when we are dealing with dark teeth, is that the more that we prep the tooth for the restoration, the darker the tooth becomes! That’s right – the enamel is filtering the darkened dentin underneath, and as we remove the enamel to gain restorative space, we make it harder on ourselves to block out the discoloration. So now that we are prepping deeper to gain space for our restorative material, the more likely we are to having to rely on dentin as our bonding substrate, rather than enamel. In this case, if I am relying on my bond to dentin instead of enamel, my choice of restorative material will always be composite. Why, you ask? For two reasons. Reason #1 – porcelain, especially zirconia, is a very stiff substrate whereas the dentin of the tooth has more flex, especially under function. Composite, in my experience, is better able to ‘bend’ and flex with the tooth structure and I find that the margins maintain better than when I have bonded porcelain to teeth with reduced enamel. The second issue, and this is critical, we must realize that regardless of the material chosen, over time, there will likely be breakdown of the restorative margin interface. A major advantage of composite over porcelain or zirconia, is its reparability. In cases of margin breakdown, or recession, I can roughen the existing composite and tooth structure, and following proper adhesion procedures, bond new composite to the existing composite covering over the failed margin or the exposed, dark tooth structure. It is my opinion that using composite to veneer dark teeth allows me to manage the inherent challenges of maintaining the restorations long term.
The other advantage of composite is that it is inherently more opaque than porcelain. We can use this to our advantage when we are working with dark teeth. But it is important to understand the step-by-step workflow when using composite. The first key when blocking out dark teeth is to use a pink opaquer as the first layer of material, after the adhesion technique. Pink opaquer is used to neutralize the dark under color. For clinicians that have tried to use white opaquers, they probably have found that when the white opaquer is used in a thin layer, the value (brightness) is low and the white becomes grey. Alternatively, when the white is used in a thicker layer, the white will become too opaque in an effort to block out the underlying dark tooth structure, and masking the white with the composite becomes impossible, resulting in an opaque, unnatural restoration. The pink opaque in contrast, when placed in thin layers, raises the value of the restorative surface without over opaquing the tooth. Utilizing pink opaquer as an undersurface allows the dentist to layer traditional composites to create a natural and esthetic final restoration.
I hope that the information on pink opaquer was
helpful in understanding its use in pre-opaquing to raise the value of the dark
Yours for better dental health,
Dennis Hartlieb, DDS, AAACD