Fig.1
Posterior restorations can be a challenge for the Dentist.
Sometimes it can be difficult to manage different aspects of the restoration:
How to manage the contact point, the shape and the occlusion.
In this case I will tell you the story of a patient who came to my practice because she had a lot of pain in the lower left area. All the teeth were vital no periodontal pocket, only a great inflammation of the gum between 3.6 and 3.7.
The diagnosis was gingivitis given by the inconsistency of the contact point.
The problem of molar 3.7 was represented by the impact of food in the space between 3.6 and 3.7 and also the distal portion was over-contoured.
We decided to improve the shape of the restoration on 3.7 in order to achieve a proper contact point and distal emergency profile.

Fig.2
Rubber dam isolation.

Fig.3
After removing the old restoration, we prepare the cavity.
It is important to etch all the enamel surface to have the best adhesion in all the marginal area.

Fig.4
It can be a good strategy to etch not only the proper margin of the preparation, but over extend a little more.
One of the problems of adhesive restorations is the possible contact between the restoration margin and not-etch enamel.

Fig.5
Selective etching of the enamel, 30 seconds.
The universal adhesives such as ( Scotchbond Universal™ etchant  3M ) adhesive is much more effective on not-etched dentine, so we DO NOT ETCH DENTINE.
Usually we protect the neighbour teeth, but in this case 3.6 it’s a ceramic overlay so we don’t need isolation.

Fig.6
Cavity dry and ready to the adhesive.

Fig.7
After placing Scotchbond Universal adhesive 3M in all the cavity by a brush, it is mandatory leave it in the cavity for at least 20 seconds.
Then distribute it with a light air gentle jet until it becomes impossible to see the small waves when the air intercepts the adhesive. The surface must always be glossy!

Fig.8
By using a black matrix (Polydentia lumicontrast) it is possible to have a better control of adaptation of the matrix on the margin thanks to its high contrast. To allow the matrix to embrace the tooth, we use a special Niti ring with specific silicone tips (My Polydentia classic ring with diamond 24 silicone tips). The most precise is the embrace between the matrix and the ring, the less time it will take for the correction at the end of the restoration.

Fig.9
Curing at least 40 seconds. In the picture Elipar deep cure 3M.

Fig.10
The pressure of the material extruding from the capsules helps to adapt it on the margin also during the construction of the mesial crest.

Fig.11
The good opacity of the material combined with the darkness of the matrix allows us to understand the thickness of the wall we are building. When it is possible to see the darkness of the matrix through the uncured composite, it means that the wall is thinner than 0.5 mm (3M Filtek body). This value changes with different composites!

Fig.12
Misura posterior on the uncured crest, will can easy copy from the neighbour how tall the crest has to be. Using the neighbour crest as a stamp, then polymerize 40 seconds.

Fig.13
One of the most important steps!
Once the marginal crest has been polymerized.
It is a good idea to open the matrix to check if the margins are good.
If we have bubbles, it will be easy to fill them with a drop of flowable composite.

Fig.14
A flowable layer is an excellent system to make the bottom of the cavity more regular.

Fig.15
Occlusal view of the flowable layer.

Fig.16
Direct reconstruction of the distal crest. Now it is just a class one restoration.
Always dividing a complex problem into many easy problems is a good strategy this is why the choice is to always transform class 2 into class 1 restoration.

Fig.17
In one shot we will fill the cavity, it was not a deep cavity and thanks to the flow layer, now it is less deep than 2 mm.

Fig.18
The material is positioned and fills the cavity very well, thanks to the good pressure of the capsule. (3M Body Filtek A2) then we will press it with Condensa LM.

Fig.19
With Condensa LM, distribute the material in the cavity trying to follow the anatomy written in the tooth.

Fig.20
The informations are written in the tooth, the next step will be designing the lines following the Essential Lines using Fissura LM.

Fig.21
How to design the lines using Fissura LM. It is important to fix the center, and always design the lines starting from the center.

Fig.22
Design the lines using Fissura LM it is important to always start from the center.

Fig.23
Polishing with Sof-Lex™ Diamond Polishing System is a quick and easy way to get fantastic result, just in two steps:
First step the brown spiral.

Fig.24
Second step the pink spiral.

Fig.25
Occlusal view of final the restoration under rubber dam.
Before cut and remove the rubber dam we will finish and polish the buccal and lingual surface by  Sof-Lex™  Pop-On and Polish the cervical portion and finish it with sof-lex strips.

Fig.26
Final result without rubber dam.

Fig.27
1 year follow up.

Conclusions

Reliable, stable materials with excellent polishing characteristics such as the 3M Filtek Supreme body, allows us to manage long-lasting reconstructions while maintaining the aesthetic & function for a long time.
Both are important target the clinicians.
In this case the tips it is what we need to give a good contact point stable during the time and an anatomy easier to be cleaned by the patient and maintained by the hygienist.