There could be a few reasons why the bonding fell off of your tooth. Many times it is due to the relationship of your upper and lower teeth causing excessive force on this area. This force could be more than the material will hold up too. Also, there could have been a problem or some contamination in the bonding process, thus leading to a weaker bond and regardless of your "bite" it would fail. I would suggest seeing the dentist who performed this and have them review your bite and if all is ok, then re-bond the area and make sure all the proper steps are followed to make sure it is bonded properly.
