How Do I Get Rid of the Odor from the Gap Between the Ceramic Caps and the Gum Line?

I've had two root canals (top left molars) along with ceramic caps fitted. I've been experiencing sever halitosis from this region. Every time I floss this area, the floss smells horrible. This happens even after I've flossed, brushed and rinsed my mouth with various mouthwashes. I've been to two other dentists who've both said that nothing is wrong. One suggested using something called "Micro-floss". I need to desperately get rid of this problem as I'm starting my new job in two week's time.