Matrix placement hack: distal areas

21 Jul 2017 - 54021

Posterior isolation helps us prevent fluids and contamination from invading the area of our restoration when going direct, and that of our build up for indirect solutions. We have several solutions for interproximal area restorations, and for those cases in which when we have deep margins to restore, as you can read in our previous articles. On the other hand, sometimes we need to put a matrix right in a place where the clamp is placed, and then our problem starts; if we want to put the matrix prior to the isolation, we can't put the rubber dam, and if we want to do the opposite, the matrix will not adjust the cervical margin. We are going to show a clinical case and a solution for those types of situation to help you in daily practice.

Fig. 1

Img. 1 – Initial situation with a lower second molar fractured in the lingual area. When we see the situation we decide to go for an indirect restoration, but, due to economical reasons, the patient decided to have a direct restoration and wait until he can afford an indirect one.

Fig. 2

Img. 2 – After anesthesia infiltration, we isolate with the rubber dam and a wingless clamp

Fig. 3

Img. 3 – Using the Direct Style bur kit we eliminate the old restoration with high speed at the beginning and a ceramic bur in 1:1 handpiece micromotor to remove the composite and respect the enamel

Fig. 4

Img. 4 – Situation after the removal of the old restoration

Fig. 5

Img. 5 – Now we get to our problem: how do I insert the matrix…?

Fig. 6

Img. 6 – In this case, any kind of matrix would collide with the clamp

Fig. 7

Img. 7 – But here is the solution, step by step, of how we make the process

Fig. 8

Img. 8 – First, we need to detach the clamp from the tooth surface only on the lingual side.

Fig. 9

Img. 9 – Of course we need the help of the dental assistant to hold the rubber dam and open the clamp a little bit with the rubber dam clamp forceps, to allow the dentist to insert the matrix

Fig. 10

Img. 10 – After that, we check that we can restore the cavity

Fig. 11

Img. 11 – We can now etch the enamel for 30 seconds

Fig. 12

Img. 12 – Apply 2% chlorexidine to stabilize the adhesion

Fig. 13

Img. 13 – Then apply your adhesive system

Fig. 14

Img. 14 – Polymerization with a deep cure polimerization lamp

Fig. 15

Img. 15 – Seal the margin with a flowable bulk fill material

Fig. 16

Img. 16 – And convert the cavity in a class I design to make it easier with a A2 body shade material

Fig. 17

Img. 17 – With the help of the spatulas and the compobrush we build up the lingual area trying to imitate the natural shape of the molar

Fig. 18

Img. 18 – We finish the build up and now we have a simpler class I situation

Fig. 19

Img. 19 – Bending the brush with a plier helps us work in posterior areas

Fig. 20

Img. 20 – We eliminate the matrix carefully and continue building up the occlusal anatomy with the same composite

Fig. 21

Img. 21 – The Fissura instrument by Style Italiano allows an ideal design of the anatomy on the occlusal surface

Fig. 22

Img. 22 – And we can smoothen everything with the Compobrush

Fig. 23

Img. 23 – After finishing and polishing, we take off the rubber dam

Fig. 24

Img. 24 – Check the occlusion with two different articulating papers

Fig. 25

Img. 25 – Conctrol 3 weeks later, after the healing of the gingiva the patient is satisfied with the result.



In the present case, the best thing would be to build up the damaged area or take an impression for an indirect restoration; as sometimes, due to the patient’s situation we need to go for a direct solution, here we show a solution for that specific moment. Can we do an indirect restoration later on? Have we done something that restricts indications for an indirect restoration in the future? We think this is another proper option to solve this particular situation.


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