All matrices are available in two thicknesses and three shapes:

shape 1 - standard shape
shape 2 - with the adjustable central part,
shape 3 - with enlarged sub-gingival ledge



When operating with a ring:
1) make sure the integrity of the ring and absence of rust on it; 
2) avoid high-speed opening;
3) open the ring not more than 10 - 12 mm width;
4) open the ring for necessary width outside the mouth before placing it on a tooth.

Liquid error: include usage is not allowed in this context