Step 2: If it's stuck on fabric, gently tug the fabric to the side and pull the slider up and down. To help the zipper work more smoothly after fixing bent teeth, lubricate the teeth, just as you would a stuck zipper. If you're zipping correctly, but your zipper is still misaligned, check the zipper for bent teeth—a single bent tooth can throw off the entire zipper. Zipper teeth do wear down over time. "Missing zipper teeth or crushed zipper sliders are generally unfixable problems for that specific zipper," says Reed.