The Middle Layer

Just a tiny amount of a strong color can completely change the outcome of a restoration, taking integration to a next level. Talking about stratification of masses, the layer located between the dentin and the enamel is called the middle layer. Paradoxically, this layer is extremely easy to reproduce when the dentinal thickness is correctly managed.
In this case report, we would like to point out the importance of reproducing white spots, a feature generally related to the enamel layer in natural teeth and reproduced in the middle layer when stratifying.

styleitaliano style italiano dentistry

Fig.1
The adjacent 21 showed a large white and opaque stain fig.1 (type 1M++++) (1 “spot” M “medium” ++++ Strong white) (1).

styleitaliano style italiano dentistry

Fig.2
Looking from a lateral view, it could be appreciated that it was not only a simple blotch, but also an hypoplasic spot.

styleitaliano style italiano dentistry

Fig.3
An underexposed picture showed the chromatic complexity of this tooth with a better contrast. (2)

styleitaliano style italiano dentistry

Fig.4
At the second appointment, after the local anesthesia, the teeth were isolated with rubber dam.

styleitaliano style italiano dentistry

Fig.5
Then the spot on 21 was slightly prepared using a low speed carbide bur in order to eliminate the rudest aspect of the opaque white spot. Less intense white spots were left intact.

styleitaliano style italiano dentistry

Fig.6
The margin on the tooth 11 was regularized with diamond removing the uneven edges of thin enamel.

styleitaliano style italiano dentistry

Fig.7
A 20 blade carbide bur was used to remove unsupported prisms invisible to the naked eye and a short bevel was prepared.

styleitaliano style italiano dentistry

Fig.8
During acid etching, two “wedgeguards” were used to protect adjacent teeth from the acid

styleitaliano style italiano dentistry

Fig.9
Adhesive procedures were performed.

styleitaliano style italiano dentistry

Fig.10
The silicon key was applied and the margin of 11 was marked with “LM Fissura” instrument.

styleitaliano style italiano dentistry

Fig.11
In order to apply the exact amount of composite to create the first palatal layer.

styleitaliano style italiano dentistry

Fig.12
A layer of A2 dentin was applied over the spot on 21, trying to cover it.

styleitaliano style italiano dentistry

Fig.13
Then a sectional metallic matrix was placed on the mesial side of 11 and blocked with a plastic wedge (Img. 17); the anatomic shape of this kind of matrix, even if designed for posterior restorations, is very helpful to give the proper curvature to inteproximal areas of central incisors.

styleitaliano style italiano dentistry

Fig.14
A thin layer of natural enamel was applied on the 21, while the central dentinal body of the 11 was made using an A2 dentin mass, mimicking the anatomy of the adjacent tooth.

styleitaliano style italiano dentistry

Fig.15
Dentinal body being modeled.

styleitaliano style italiano dentistry

Fig.16
Dentin body finished must have the right thickness in order to obtain an optimal enamel-dentin ratio.

styleitaliano style italiano dentistry

Fig.17
As one of the most important stages, the white spot fabrication (type 1S ++) on the 11, applying a white stain with the LM “Fissura” instrument, according to the programmed characterizations decided on the color analysis phase.

styleitaliano style italiano dentistry

Fig.18
The characterizations modeled and polymerized.

styleitaliano style italiano dentistry

Fig.19
A final layer of natural enamel was applied on the vestibular surfcae, making sure thant the margin is perfectly sealed, but without surpassing the margin.

styleitaliano style italiano dentistry

Fig.20
Glycerin was used to improve the light curing.

styleitaliano style italiano dentistry

Fig.21
Prolonged light curing (not optional). under glycerine (optional).

styleitaliano style italiano dentistry

Fig.22
Finishing procedure was made with “LM Eccesso” instrument, and a diamond bur on contra-angle (Perioset, flame bur); it is highly efficient and it allows the clinician to control speed and torque very easily.

styleitaliano style italiano dentistry

Fig.23
After polishing with silicon points, stripes and pastes, the rubber dam can be removed.

styleitaliano style italiano dentistry

Fig.24
Immediate aspect of the teeth whithout rehydration.

styleitaliano style italiano dentistry

Fig.24
Before the restorations.

styleitaliano style italiano dentistry

Fig.25
After two weeks, the good integration of the restorations can be appreciated, together with the natural aspect of the white stains.

Bibliography

1. Manauta J, Salat A. Layers, An atlas of composite resin stratification. Chapter 4 and 5, Quintessence Books, 2012.
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;6:280–-296.
3. Devoto W, Saracinelli M, Manauta J.Composite in everyday practice: how to choose the right material and simplify application techniques in the anterior teeth.Eur J Esthet Dent. 2010 Spring;5(1):102-24.
4. Vichi A, Fraioli A, Davidson CL, Ferrari M. Influence of thickness on color in multi- layering technique. Dent Mater 2007;23:1584-9.

Previous articleNo-prep Additive Veneers
Next articleCustom Rings

RELATED CASES

There’s much more to a smile than space closure

In this multidisciplinary article, a maxillary midline diastema was solved including orthodontic resolutions combined with periodontics and restorative dentistry.