Controlled body thickness part 2

Correct layering of the enamel and dentin is one of the most important goals in aesthetic stratification, this will allow us to easily understand which extra masses besides enamel and dentin are necessary or not. Surprisingly, enamel and dentin are more than enough to obtain ordinary or high end aesthetic results in most of the cases. The importance of layering correctly the thickness of the enamel will show the user that the middle layer, those masses that go between the enamel and dentin are usually extremely thin and are not the most important masses.

From the technique developed by Walter Devoto and Angelo Putigano with the styleitaliano group, a clinical case by Jordi Manauta, Gaetano Paolone and Louis Hardan

The systematic use of two masses, one dentin (In) and one enamel (Out) has been widely used since almost centuries. There are plenty of examples of the successful use of only two masses in dentistry; such as denture teeth, generally made of an acrylic opaque mass and a translucent enamel, the same case in many commercial shade guides with opaque ceramic dentin and a translucent enamel, it is fair to say that no one would question the beauty of these teeth that are widely used.

As we have noticed in different composite found in the market, almost every enamel and dentin differ in opacity and translucency from one another, even if they are very similar, small changes can provide dramatic outcomes. After thorough studies of the composite enamel and composite dentin refraction indexes, opacity values and other optical features, it is clear from clinical evidence and research that a 0,5mm enamel thickness gives the most consistent result in its systematic use and in a wide range of materials.

The following case will demonstrate the clinical performance of the CBT technique, and how the use of two masses with perfect enamel/dentin association will not have a negative influence in the final aesthetic outcome but in most cases all the contrary. It will also give a full understanding of extra masses use (such as the translucent mass used in the case) and its capacity to improve the overall quality of the final outcome of the restoration.

Dentists often use a multi-color layering technique, especially during their first attempt of stratification. The use of many colors can give importance to special effects which may lead to a beautiful restoration but unfortunately, it does not integrate at a marginal level or in the overall value or opacity. Sometimes even the color is completely missed, that is why in our experience we can say that less is better.

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Fig.1
The coauthors of this article which I would like to thank for their precious collaboration, help and brainstorming are Gaetano Paolone, Louis Hardan, Walter Devoto and Angelo Putignano

style italiano styleitaliano dentistry

Fig.2
Initial situation of a tooth 11 that has an inappropriate restoration. In a quick analysis, this restoration is not completely wrong, in terms of opacity and value, but in a deep analysis it is clear how the shape, tooth dimension, surface texture, gingival over contour are the reasons for the replacement of this restoration. Given the fact that this outcome must be improved, all variables must be taken into consideration, especially the color and the morphology.

style italiano styleitaliano dentistry

Fig.3
Complete isolation is the first step. It is important to know that placing the rubber dam is not enough, it has to be well positioned so it does not infiltrate or interfere with the operative steps. A clean and visually perfect rubber dam is of outmost importance, because this step can drastically influence the outcome of the restoration.

style italiano styleitaliano dentistry

Fig.4
With the first step of “direct style bur” the margin will be located. It is a hard task sometimes, especially if a good bonding was realized previously and there is a fair enough color blending. It is mandatory to remove the full restoration without harming the sound dental tissue. To do so, a low speed bur must be used in order to remove the composite from the interface without causing any harm to the enamel and to locate the boundary between the tooth and the restoration.

style italiano styleitaliano dentistry

Fig.5
Once the margin was located, the second step from the “direct style” bur sequence will be used to quickly remove the full restoration.

style italiano styleitaliano dentistry

Fig.6
At this point, unfortunately, many dentists give the cavity as good enough as the starting point and continue to the bonding stage, which makes it clear why many restorations fail and why many dentists still don’t believe in adhesive dentistry. In this picture it is shown that an over hanging is present at the mesio-gingival area, giving a false over contour that pushes the papilla and gives the tooth the wrong dimension. A special instrument “Eccesso” LM arte by Styleitaliano (Excess) was used to remove manually this excess in a safe and efficient way.

style italiano styleitaliano dentistry

Fig.7
With the step 3 of “Direct style bur” which is a low speed small rounded carbide bur, the closest and invisible composite excess will be cut efficiently, as well as caries or other debris.

style italiano styleitaliano dentistry

Fig.8
The cavity after step 4 and 5 of the Direct Style burs. The aspect must be smooth clean and uniform.

style italiano styleitaliano dentistry

Fig.9
Bonding procedures, with selective acid etching and an Etch and dry technique.

style italiano styleitaliano dentistry

Fig.10
Extended polymerization of the bonding layer is of outmost importance.

style italiano styleitaliano dentistry

Fig.11
On the mesial wall of 21, a small increment of composite was placed in order to give back the right dimensions to the left incisor and consequently to the right incisor, This decision must be made on the preliminary shade and shape estimation. The aspect of the hybrid layer should be smooth bright and polished. The substrate is now ready to receive the composite.

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Fig.12
The palatal wall is built with the chosen enamel with the aid of the silicon index that was previously obtained from the modified old restoration. The palatal wall must be thin, it will be strong enough to give support to the following masses.

style italiano styleitaliano dentistry

Fig.13
The use of an inverted posterior matrix (how to choose a matrix part 2) gives an amazing contour to the proximal walls. The matrix choice is done systematically in anterior teeth, the use of flat transparent strip has been relegated to almost zero as they throw out very inconvenient results regarding proximal shape. This strategy is easy, fast, affordable and accessible to anyone.

style italiano styleitaliano dentistry

Fig.14
A close up of how the matrix should adapt to the tooth and the composite wall.

style italiano styleitaliano dentistry

Fig.15
Proximal wall after matrix removal. The contour of the wall is precise, rounded and clean, especially in the cervical area where no excess is present.

style italiano styleitaliano dentistry

Fig.16
With the bur 3 of “Finishing style” which is a low speed diamond bur, corrections can be carried out if needed as described in Controlled Body Thickness Part 1, dust removal was done with solvent-free bonding.

style italiano styleitaliano dentistry

Fig.17
Dentin is placed in bulk, no special attention was paid during this step.
The main tip for this article: before curing the dentin composite, with the “Misura” instrument a space is created for the enamel by passing the instrument several times across the margin, this technique will allow to remove the composite excess for the 0.5mm space needed for the enamel.

style italiano styleitaliano dentistry

Fig.18
The full dentin body is calibrated with the “Misura”, the composite excess is removed and the incisal edge is modeled in order to leave space for the enamel and translucent masses. The polymerization step is completed

style italiano styleitaliano dentistry

Fig.19
Translucent enamel was used in the incisal edge and proximal wall to mimic most of all the strong opalescence in the proximal wall.

style italiano styleitaliano dentistry

Fig.20
The last enamel layer is placed as smooth as possible.
Tip: If there are some irregular areas or bubbles, it is possible to add a little bit of flow in the suspected area. It is better to fill up with flow at this stage than to have bubbles in the finishing stage.

style italiano styleitaliano dentistry

Fig.21
The most important phase of the finishing and polishing stage is the rough finishing, doing too little will result in a restoration impossible to polish with a very bad surface aspect and texture. The strategy the authors propose is to do the finishing stage with a low speed medium/coarse diamond bur (Step 3 of “Finishing Style”), to smooth the surface in a very similar way as the ceramists correct their restorations between oven cycles. This allows the clinician to have an effective bur, but delicate enough to respect the material and not to damage it with a high speed and less controlled bur.
The aspect of the composite after the first stage of finishing should be similar to that of the ceramic ready for biscuit stage. It is after we accomplish this aspect of the composite, we can proceed to other stages.

style italiano styleitaliano dentistry

Fig.22
With step 1 bur of “finishing style” which is a multi-blade low speed big round bur (generally used for posteriors) we can develop secondary anatomy with very gentle touches. It is possible to go back to the diamond bur in any moment. In this case lobes are drawn with a pencil imitating those on the adjacent tooth and then carved with much care in the new composite restoration.

style italiano styleitaliano dentistry

Fig.23
After the finishing stage, polishing is rather simple. In fact following the method described under, the clinician must be careful not to obtain too much polishing.
Summary of the finishing stage
a) Finishing Style step 3 (low speed diamond bur)
b) Finishing Style step 1 (low speed multi-blade round carbide bur)
c) Finishing Style step 3, used again if needed to smooth the surface
Summary of the polishing stage
d) Abrasive rubber point (Shofu One gloss) with very soft touch to erase the marks of the diamond bur
e) Goat brush cup (Kerr) and diamond paste (Diamond Twist SCL)
f) Felt Wheel (Micerium) and Opal L paste (Renfert)

style italiano styleitaliano dentistry

Fig.24
After rubber dam removal, the restoration looks slightly yellowish, but at this moment this is normal, final evaluation must be done after Rehydration and no decision regarding color must be taken now.

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Fig.25
The restoration after a week check-up shows excellent color integration, and overall mimicry thanks to the primary shape, secondary and tertiary anatomy and adequate polishing.

Conclusions

In the developed color recipes, it is easy to take the Vita shade guide, match the color and build up the two suggested colors, the upcoming articles will show how sometimes other shades can be combined in order to obtain colors different from those in the suggested recipes.

Find out more on Controlled Body Thickness (CBT) Controlled Body Thickness Part 1 and part 3.

Bibliography

1. Manauta J, Paolone G, Devoto W. 2013 IN ‘n’ OUT – A New Concept in Composite Stratification. Labline Magazine, 3(2);110-127
2. 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.
3. Manauta J, Salat A. Layers. An atlas of composite resin stratification. Quintessence Books, 2012.
4. Baratieri LN. Soluciones Clinicas: Fundamentos y Tecnicas. Sao Paulo: Livraria Santos, 2009.
5. Dietschi D, Ardu S, Krejci I. A new shading concept base on natural tooth color applied to direct composite restorations. Quintessence Int 2006;37:91-102.
6. Vanini L, Mangani F, Klimovskaia O. Conservative Restoration of Anterior Teeth. Viterbo, Italy: Acme.

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