Problems and Complications with Lumineers?

The answer is simple.  Avoid Lumineers if possible!  The porcelain is of poor quality.  The Lumineer people recommend finishing the edges at the gum line of the Lumineer with a dental bur (drill) which is an absolute no no with veneers.  Often the Lumineers are overcontoured which can cause chronic gum inflamation. 

Lumineers are one brand of prepless veneers. There are many brands and performed properly are a durable, healthy and esthetic solution to many smile issues. Bad Breath may occur from a poor seal when bonding the veneers and bacteria collecting under the restoration. Fractures can occur from a poor bonding technique, inappropriate design of the bite, or excessive clenching and grinding without a night time appliance. And placing the Veneers too car under the gum can cause a non healing... more

Lumineers is touted as "no prep" veneers. If there is no margin (recessed edge), then there will be a ledge at the edges. This can trap plaque, which can smell or stain. Trapped plaque can also lead to gum disease. Bulky edges can irritate gum tissues, leading to gum disease. Since they are very thin, they are more prone to break. Not all Lumineers cases are terrible, but often these cases disappoint people and get replaced.