Grey margins: 4 mistakes to avoid

I am still seeing that grey line. My restoration is visible. What can we do when our anterior restorations keep failing aesthetically? By following a couple of simple actions, we will change the way we perform everyday dentistry. These actions are actually nothing elaborated or complicated: on the other hand, they are extremely simple, and the only thing they require is constancy.

style italiano styleitaliano dentistry

Fig.1
It is very frequent to obtain gray restorations when working with composites. Each composite has different optical behavior, but, speaking in general, by increasing the thickness of composite enamel, we actually make the restoration become greyish.

style italiano styleitaliano dentistry

Fig.2
We can see three glasses in which there is a glass another glass inside. In the first picture, on the left we can appreciate both glasses. However, in the third one, there is also a glass inside but there is material between them, which makes it optically disappear. This is a light effect in which the refraction and reflection indexes are equal. In a restorative material, researchers serch for this effect, for the light to travel in the same way as in a natural tooth. The refraction index tells us how the light will pass through an object and in which direction it’s gonna go. The way that the light travels in the enamel is very effective, as it is reflected and refracted a lot, but usually in composites the light travels less efficiently.

style italiano styleitaliano dentistry

Fig.3
Dentists, when obtaining grey composites could decide to change for a more whiteish enamel. When adding white to an enamel it becomes more opaque. But this is not convenient because we need translucent enamel masses to be able to see the dentin color and effects beneath the enamel layer. The key factor is on enamel thickness. We must reproduce enamel composites in a smaller thickness than the natural enamel to achieve an optical integration. This is the only way to make two completely different materials look the same. The most frequent mistakes are the following 4.

style italiano styleitaliano dentistry

Fig.4
MISTAKE no. 1 – USING THE VITA SHADE GUIDE AS THE ULTIMATE REFERENCE
Take your vita shade guide and then take your syringe with the same name (e.g. A2) printed onto its label. I had the opportunity to be in touch with dentists from all around the world and I frequently see that is usual to use vita shade guide to choose the color when performing direct composites. What happens if an A3 color from the vita shade guide is chosen and then you pick up an A3 syringe from the composite system you have in that moment? Is more than sure that you are committing a mistake. (1,2)

style italiano styleitaliano dentistry

Fig.5
MISTAKE no. 2 – BELIEVING THAT DIFFERENT BRANDED COMPOSITES WILL LOOK THE SAME
An A3 from one brand is completely different from another brand. In this image we can see 8 syringes named A3 dentin on their labels. Different brands, same names, and completely different properties. Different hue, chromaticity and opacity. It’s impossible to have predictable results if you believe that A3 are all the same.

style italiano styleitaliano dentistry

Fig.6
MISTAKE no. 3 – NOT CAREFULLY CONSIDERING THE MARGINS
Sharp margins must be finished and polished: trying to restore sharp margins just like these will most probably end up in aesthetic failure.

style italiano styleitaliano dentistry

Fig.7
To hide the margin we usually use a long bevel (between 1.5mm-2mm).

style italiano styleitaliano dentistry

Fig.8
Margin polishing can be done with an abrasive disc, or a rubber tip or a multi-blade bur.

style italiano styleitaliano dentistry

Fig.9
MISTAKE no. 4 – NOT CALCULATING THE ENAMEL THICKNESS
Issue: some dentists don’t even know the enamel thickness they used. It is crucial to reproduce the precise enamel thickness to obtain the right color. We prepared composite discs, different enamel thicknesses, to better understand the behavior of composite. We prepared discs from different composite brands, and, in general, when using 0,3 mm enamel on dentin, the enamel effect is almost imperceptible. 0,5 mm is the right compromise because it modifies the dentin but without lowering value; 0,7 mm enamel thickness is usually too much because restorations become grey. When 0,9-1 mm thicknesses were used, the enamel hid the dentin and lowered the value.

style italiano styleitaliano dentistry

Fig.10
The key factor is to control the enamel thickness (3,4,5)

style italiano styleitaliano dentistry

Fig.11
We usually use instrument Misura (LM Arte kit) to measure the 0,5 mm ideal enamel thickness.

style italiano styleitaliano dentistry

Fig.12
The opposite end is useful in narrow areas or near the cervical third where the “probe end” does not fit.

style italiano styleitaliano dentistry

Fig.13
Class IV fracture, after radiological evaluation, color was taken with a custom shade guide (6)

style italiano styleitaliano dentistry

Fig.14
Isolation and cavity preparation.

style italiano styleitaliano dentistry

Fig.15
Proximal and palatal wall build-up: after having this structures, dentin can be inserted and calibrated.

style italiano styleitaliano dentistry

Fig.16
A White halo was created with a tiny amount of A1 dentin.

style italiano styleitaliano dentistry

Fig.17
After enamel placement.

style italiano styleitaliano dentistry

Fig.18
Result after rehydration. In some situations the result is not perfect but in most of the cases the aesthetic result satisfies the doctor and patient expectations.

style italiano styleitaliano dentistry

Fig.19
Class IV fracture before restoring.

style italiano styleitaliano dentistry

Fig.20
I followed exactly the same protocol to hide the margin. It is important to use a personalized shadeguide to choose the color, to bevel the margin, to polish and finish the margin and control the enamel thickness.

style italiano styleitaliano dentistry

Fig.21
Class IV fracture before restoring.

style italiano styleitaliano dentistry

Fig.22
The same concepts are taken into consideration in each clinical case when dealing with anterior restorations.

style italiano styleitaliano dentistry

Fig.23
Class IV fracture and old composites.

style italiano styleitaliano dentistry

Fig.24
Isolation.

style italiano styleitaliano dentistry

Fig.25
Finishing steps.

style italiano styleitaliano dentistry

Fig.26
Exactly the same concepts are used by other doctors (this is Dr. Walter Devoto’s clinical case) with predictable results in the daily practice.

Conclusions

Keep in mind that:
– VITA color is not what you get in your material
– All composites have different color and opacity
– Margins should be beveled and thoroughly cleaned
– The thickness of your enamel has to be 0,5 mm, or very very close to that value
The margin error rate in anterior restorations will tremendously decrease, with no fancy equipment and no complicated techniques.

Bibliography

1. Browning WD, Contreras-Bulnes R, Brackett MG, Brackett WW. Color differences: polymerized composite and corresponding Vitapan Classical shade tab. J Dent. 2009;37 Suppl 1:e34-9.
2. Kim HS, Um CM. Color differences between resin composites and shade guides. Quintessence Int. 1996 Aug;27(8):559-67.
3. Manauta J, Salat A, Putignano A, Devoto W, Paolone G, Hardan LS. Stratification in anterior teeth using one dentine shade and a predefined thickness of enamel: a new concept in composite layering–Part II. Odontostomatol Trop. 2014 Sep;37(147):5-13.
4. Manauta J, Salat A, Putignano A, Devoto W, Paolone G, Hardan LS. Stratification in anterior teeth using one dentine shade and a predefined thickness of enamel: a new concept in composite layering Part I. Odontostomatol Trop. 2014 Jun;37(146):5-16.
6. Kahng L. Custom shade matching: fine-tuning and patient communication lead to success. Compend Contin Educ Dent. 2011 Oct;32(8):68-70, 72-4, 76.)
7. Salat A, Devoto W, Manauta J.Achieving a precise color chart with common computer software for excellence in anterior composite restorations. Eur J Esthet Dent; 2011;6(3):280-96.
8. Manauta J, Salat A. Layers, An atlas of composite resin stratification. Quintessence Books, 2012.

RELATED CASES

Teeth Recontouring and Shape Perfecting

In this article we will show how we can use direct composite veneers to correct the alignment and also modify the shape of teeth to make a smile beautiful.
styleitaliano style italiano silicone index positioning under rubber dam isolation

Double-mold Technique

styleitaliano style italiano composite restoration of premolar and molar

Free hand vs Sectional band