DOUBLE MATRIX WHY & HOW?

How many times do you see cases that need DME? 

How Many times do you see S-shaped Margins? 

that 2 questions here we will answer them using the Double Matrix Technique.

let's go first with the technique 

when you applicate the matrix between the teeth under a microscope sometimes see gaps, between the margin and the matrix. 

it's now easy to be handled through the double matrix technique.

first of all 

put your sectional / saddle matrix or whatever matrix system you use 

then put your wedge, 

(notice that in S-shaped margins we use diamond wedge from bioclear )

now under Microscope, you will see that gap still exists.

so put your second matrix, notice the gap still exists? No, 

so you are now ready to put composite.

but what if the gap still exists? 

Tip 1 

Insert Teflon between the matrices so now you are securing the margin from any leakage, 

but here is the first disadvantage of inserting Teflon 

inserting Teflon between the matrices makes deformation for the second matrix, so we will use the second matrix for Elevating the margin that went deep because of caries only then remove it.

Tip 2 

Do not remove the wedge because of the capillary action that makes blood escape from the high-pressure area to the low-pressure area so the blood will fill the cavity again and you will need to do the bonding step again.

Note 

  when you elevate your deep margin it is the time now to remove the second matrix , but sometimes you don't have to remove the second matrix in cases such as : 

Class 2 for last molar because you don't have contact to preserve here .

disadvantage 

when you leave the double matrix while building up the missing wall like in class 2 , you double the matrix thickness here so you have double space which means open contact .

which it is something we don't need