Veneers can fall off for a host of reasons, just like crowns and fillings can fall out.There are several conditions that make a veneer more susceptible to coming off. For instance, if the veneer is on a small tooth it will be more likely that it will come off than a large tooth. Here, the issue is amount of surface area that the dentist has to bond the porcelain onto the tooth.Another reason veneers may come off is some kind of force that dislodges them. It could be biting on hard food? Also, a blow to the tooth, like hitting your tooth on the steering wheel in an accident. A third reason relates to the materials and techniques utilized by your dentist. Probably one of the most common reasons veneers can come off is if the patient is a bruxer or grinder. Dentist can usually spot patients who do this and commonly recommend that their patients wear a night guard at night to protect the bite and the veneers.