Fig.1
These are the Essential Lines

Fig.2
And their purpose is to move from point A to point Z… saving time.

Fig.3
We reproduced them both from superior and inferior posterior teeth, copied them from the natural tooth, but shaping down to the basic few lines, i.e. the essential ones that are enough to capture the idea of a tooth.

Fig.4

Fig.5
Fill, stratify, put the material into the cavity up to 1.5 mm from the cavity edge, in the way you prefer: horizontal, oblique, respecting the C factor.Posterior misura LM Artecan lay on the edge of the prepration because of its shape and measure 1.5 mm thickness that will represent that of the final layer of the restoration.

Fig.6
It is important to be careful to remove all the composite excess and to properly distribute the composite on the margins

Fig.7
Essential Lines are used to draw the sulcus.

Fig.8
Essential lines and bulk & body is some tasty combination. Combining bulk material and body, bulk can be used to fill the cavity all at once and, thanks to the Posterior Misura instrument it is possible to calibrate the thickness of the final layer.

Fig.9
To have the best performance from both materials and achieve the best result with body on the occlusal surface and bulk below, thickness control is really important.

Fig.10
If we decide to use a bulk material to fill the entire cavity altogether, the Essential Lines will help us to form the occlusal anatomy without losing its proportions and in a simple way.

STEP BY STEP PROCEDURE
A key point is not to lose information about the tooth, from the residual anatomy. Certainly the best way to find information is to not to miss it!

Fig.11
Hint no. 1: inclination of the residual cusps

Fig.12
Hint no. 2: location of the sulci, or what is left of them.

Fig.13
So, place the material by compacting it with Condensa LM Arte on the entire occlusal area.

Fig.14
It is important to lay the Condensa LM Arte instrument on the cusp to copy its inclination. This way we also remove the excess material.

Fig.15
With the Fissura instrument we can draw the sulci and improve the marginal adaptation of the material, to reduce the finishing time and the restoration.

Fig.16
A key point is to determine the center of the modeling, it is the correct base to orient the lines. It will be the starting point of the lines while the tooth tells us where it should end, we just have to connect the dots following the design of the Essential Lines.
Once the sulci are drawn, we can decide whether to add secondary slots like the one in blue if the tooth anatomy requires it.
A clinical case is here shown to explain the step by step.

Fig.17
Pre op; cavity clean; composite in place and condensed with the Condensa instrument on the whole occlusal surface.

Fig.18
Track the center; start designing the lingual sulcus; then the mesio-buccal.

Fig.19
The instrument movement to trace the groove must be from the center to the periphery for a more proper displacement of the material.

Fig.20
As a final step we use a Compobrush to make the anatomy more gentle, and we enhance with a stain into the sulcus.

Conclusions

New materials allow to reduce the polymerization contraction and, hence, a more effective deep polymerization.
Today, modeling the entire occlusal anatomy at one time is becoming more and more a necessity if we are to exploit new materials. This can lead to better results in terms of time and quality, if we spend less time to layer, we have more time for the details and/or to finish and polish the restoration.
Thanks to Roberto Spreafico, who inspired this approach.
Thanks to the Style Italiano Team, and, of course, our readers, that make our ideas go far!

Bibliography