She’s back, and she’s not happy. The composite that you placed last month on tooth #9 is already staining. She especially notices that her lipstick sticks to the bonded tooth.
If this hasn’t happened to you, it’s probably because your composite polishing techniques for anterior composite restorations are great. But some of you might notice this staining even if you are being diligent with your polishing techniques.
Before we begin the conversation
on technique for polishing, we need to discuss the various composites that are
in the marketplace, and the “polishability” of those materials.
It’s been my experience that
many dentists are unsure of the ‘type’ of composite they are using in their
practice; let’s review this issue first.
Most, but not all, composite systems today are nano based – either nanofills or nanohybrids. These nano-based composites are generally referred to as ‘Universal Systems’.
Before the nanofills were introduced to dentistry, dentists were typically using microhybrids. The microhybrids were the universal composite back in the late 1980’s thru the 1990’s. The challenges that we encountered typically with microhybrids was a lack of a durable polish. We would be able to get a decent polish initially, but the polish faded away quite rapidly after the patient left, due to tooth brushing and the foods and drinks that the patient consumed.
An alternative to using the microhybrids, was to use microfilled composites on the esthetic surfaces of teeth. Microfills, given their smaller particle size and shape, are able to be polished to a much higher luster than the microhybrids, and the polish is long lasting.
Unfortunatley, the microfill composites have poor flexural strength and are prone to fracture if used on a biting edge. To prevent the microfill fracturing, microhybrid composites would be used to support the microfill, combining the best properties of both materials.
The nano-based composites were
introduced to dentistry in the late 1990’s as a ‘Universal’ composite – strong
enough to replace the microhybrids where needed for strength, and as polishable
as the microfills, where needed for high esthetics.
While the nano-based composites
are a step in the right direction for a true ‘universal’ material, evaluation
of these materials over time have found that while they are strong, and can
replace the microhybrid composite, they are not quite as flexure resistant as
the microhybrids. And while the
nano-based composites are more polishable than the microhybrids, they fall
short of the polishability of the microfills 1.
In my dental practice, for anterior teeth, I tend to use either a
microhybrid (if I need greatest strength) or a nanofill for the palatal wall of
an anterior restoration. I’ll use a microfill for the facial surface which
gives me the ultimate polishability and luster of the restoration. If I am less
concerned about ultimate esthetics, like when I do prototype or transitional
bonding, then I tend to use a nanofill, or nanohybrid, composite which gives me
good strength, and good polishability.
Our composite polishing systems today are a bit confusing. To
simplify our conversation, we’ll break the polishing systems down to either a
disc system, or rubber-based polishers.
These polishers will typically have diamond or other abrasive
particles impregnated into the polisher which, when used over the composite,
will remove surface defects and create a smooth surface.
They come in a variety of shapes and sizes, but typically are brush, wheel, cup or
point shaped. The polishers are use with a slow-speed handpiece at a slow, to
moderate speed, with light to moderate pressure.
I have come to favor the
‘Feather-Lite’ polishers from Brasseler when
I’m using a rubber-based polisher for anterior composites. For posterior restorations, I may still use
the feather-lite polishers, but tend to use cups, points or brush shape
polishers to be able to more adequately polish the composite, and the composite-tooth
interface.
