The Essential Lines Technique. Fast and Predictable Anatomy in Posterior Composite Restorations.

The Essential Lines technique was created to shape the occlusal anatomy at one single time, without missing proportions or valuable information which is drawn onto the tooth surface.
It is easy and for everyone, so that it can really improve your daily practice.
The 3 most important characteristics of the Essential Lines technique are:
1. Its fast learning curve.
2. It gives predictable results, not depending on the clinician’s personal skill or the artistic inspiration of the day.
3. It allows you to schedule your agenda more efficiently, as it’s faster than the traditional layering techniques and doesn’t really take more time if more anatomy is lost.

anatomical features of upper molar

The key to acing this technique is reading the tooth. It’s very important to keep all the available anatomical information, in order to make modelling even easier. So it’s crucial to keep sound sulci.

starting points for modelling molar

The peripheral anatomy is very useful when using this technique. The dots you see are the starting point for our future design.

bulk single layer filling

The first step to this technique, is the single mass layering. The composite paste is placed inside the cavity and compacted thoroughly, in order to avoid bubbles.
Capsule composite pastes might be easier to handle compared to syringe materials, as the pressure will make the paste just kind of flow into the cavity in one increment.

lm arte condensa for cusp inclination

To avoid getting flat restorations and lots of excess material, the LM Arte Condensa is ideal to start spreading the composite resin following the inclination of the cusps.

amalgam filling on molar

This may remind you of amalgam modeling, from which there are a couple differences:
1. Amalgam was moulded by reduction, while composite can be spread to adapt to the walls of the cavity.
2. Amalgam was very easy to distinguish from the white tissues of the tooth, while composite is often hard to distinguish from a white background, and requires much more attention not to leave excess material, which would require additional time at the end of the session to remove.

different diameters of styleitaliano composite spatulas

Not all teeth look the same, as we tend to draw them. In the real world, we need to adapt our restoration to very complex and different anatomies, with variable depths of pits and fissures. That’s why we need the right tools!

lm arte condensa styleitaliano spatula for composite packing

The LM Arte Condensa is ideal to pack the composite following cusp inclination in order to get the general shape of the tooth just right.

pit design in composite paste with fissura styleitaliano instrument

The tapered end of the LM Arte Fissura will help separate cusp anatomy and design pits and fissures.

thin instrument by styleitaliano for grooves

The probe-like end of the LM Arte Fissura is ideal to draw the sulci.

essential lines in upper posterior dental anatomy

When you decide to copy, it is essential to copy from someone very good, and who can do better than nature itself. I have designed the essential lines that make a tooth look like a tooth. In this picture, you can see the upper posterior Essential Lines.

essential lines in lower posterior dental anatomy

And the lower Essential Lines.

first class cavity on upper molar

This is a molar case. Here’s how easy it is to get a perfect single layer restoration.
You just need to follow the instructions that are drawn on the surface of the tooth.

bulk composite in first class cavity

Here’s the single bulk layer.

central pit in upper molar composite modeling

Now we have to design our surface. First of all, set the center of your restoration, and once your central pit is marked, you can start. Drawing a line is much simpler if you move from the center outwards.

first sulcus in composite modelling

Now we can start drawing our lines, following the essential design.

essential lines in composite posterior design

As you can see, after having drawn your Essential Lines, finishing the anatomy is a piece of cake. This anatomy can be improved by closing and opening the fissures or by designing secondary ones.

anatomy with essential lines on upper molar composite

What’s special about this approach, is you have a very fast, basic, predictable way to draw the basic anatomy to make your restoration immediately lifelike.

staining the composite sulci for lifelike composite restoration

Sometimes it is nice to stain the sulci, especially if they are a characteristic we can find in the neighboring teeth. On the procedural side, staining is an excuse to light cure once more, which is never enough.

finished composite restoration on upper molar

And here’s the finished restoration.

old composite MOD restoration

In this second case, we needed to replace an old composite MOD restoration. As this kind is quite a large cavity, we have a higher risk of losing reference.

distal incorrect contact point

After isolating with the rubber dam it is even clearer how the mesial of tooth 17 kind of invades the space of the old restoration on distal 16.

proximal cavity and old composite and amalgam

The space between teeth 16 and 15 looks funny.

MOD cavity and proximal caries

So, first thing, we remove the old composite restoration. First we will clean the lesion on tooth 15 and adjust the restoration on mesial 17.

clean MOD cavity on upper molar

The we concentrate on cleaning the cavity on 16 and on smoothening the margins.

bulk one shot filling

Of course, first, we build the proximal walls, so we can later concentrate just on the anatomy. At this point, with this kind of case, our session is almost over, so we really need a fast way to get this done.

essential lines for groove dental composite restoration

The cusps will guide us, so with just a few Essential Lines we can draw a lifelike surface and make our tooth quickly look like a tooth.

pop on disc for margin finishing

If we save time building-up the restoration, we will have time for the finishing and polishing step.

pop-on disc for excess composite removal

This step is one of the main reasons why I need time left at the end of the session.
I need to better define the anatomy, and to remove excess composite.

spiral wheel for posterior composite polishing

And then I want to polish the margins very thoroughly.

spiral wheel for posterior composite polishing the grooves

I want my composite to shine, as a glossy restoration will last longer and retain less bacteria on its surface.

finishing strip for proximal polishing of composite

A finishing strip can be really useful to finish the cervical area. As curing is never too much, polishing isn’t either!

glossy composite restoration

Long-term success strictly depends on these two steps!

perfect composite resin restoration on upper molar

And here’s the final result. High gloss, proper occlusion, and proper curing are the basics for long-term success. No patient with proper, thorough hygiene can keep up with rough, plaque-retentive restorations!


As time goes by, finding faster and more efficient protocols is becoming more of a necessity. As new materials allow us to meet our patients’ timing requirements, we also need faster, but reliable techniques, to make dentistry better. To make life better.


1. Dhadwal AS, Hurst D. No difference in the long -term clinical performance of direct and i indirect inlay /onlay composite restorations in posterior teeth. Evid Based Dent. 2017;18(4):121-122.
2. da Veiga AM , Cunha AC, Ferreira DM, da Silva Fidalgo TK, Chianca TK, Reis KR, Maia LC. Longevity of direct and indirect resin composite restorations in permanent posterior teeth: A systematic review and meta-analysis. J Dent. 2016;54:1-12.
3. Monterubbianesi R, Orsini G, Tosi G, Conti C, Librando V, Procaccini M, Putignano A. Spectroscopic and Mechanical Properties of a New Generation of Bulk Fill Composites, Front. Physiol. 2016;7. doi:10.3389/fphys.2016.00652.
4. Hirata R, Kabbach W, de Andrade OS, Bonfante EA, Giannini M, Coelho PG. Bulk Fill Composites: An Anatomic Sculpting Technique. J Esthet Restor Dent. 2015;27:335–343. doi: 10.1111/jerd.12159.


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