One of the largest complaints I hear about posterior composites is in our ability to predictably create tight interproximal contacts. I often joke that when I am ready I take the floss from my assistant, place it in the occlusal embrasure, turn my head and say a prayer before I try and pop it through to the gingival embrasure. Over the years it has been the combination of multiple steps that have helped me overcome this technique challenge. The first thing I do is pre-wedge any tooth that will be prepared with an interproximal box. This step creates adequate tooth separation to overcome the thickness of the band.
Step two is to make sure I have adequate convenience form. This is the space between the walls of the box and the adjacent tooth. If I have a minimum of .5mm of clearance around the walls of the box I can shape the band to create the curve toward the buccal and lingual, as well as seal these margins with my separator ring. Next I place a sectional matrix, replace larger wedge and lastly a ring that has not been stretched or fatigued.
Prior to placing the composite evaluate the band and make sure when looking from the lingual that the dimension of the contact of the band to the adjacent tooth is adequate as well as the width of the contact from buccal to lingual. Narrow contacts will snap to floss and still pack chicken and steak resulting in patient complaints and recurrent decay and gingival issues.