Veneer debonded after I sneezed

It's certainly unsettling to experience a veneer de-bonding, especially after an accidental impact like a sneeze. The immediate step is to visit your dentist to assess the damage and determine if the veneer can be re-bonded or if a new one is needed. Veneers generally have a robust attachment, but sudden impacts can compromise their bond.

Considering you've had two sets of veneers with the first set lasting six years and the second set currently in use for two years, it sounds like they've generally been successful. One veneer de-bonding doesn't necessarily mean that your other veneers will fail, but it's a good idea to discuss with your dentist any preventative measures you can take to minimize further incidents, such as wearing a protective mouthguard during activities that might put your teeth at risk. Also, have your dentist check the integrity of your other veneers during your visit to ensure they are all secure.

This sounds like an unfortunate accident, and there’s no need to be too worried. Teeth can sometimes come together forcefully by accident, and even natural teeth can chip in such situations. I recommend having it rebonded and moving forward. If it happens again or if you’d like a more in-depth evaluation, consider seeing a prosthodontist or a dentist with advanced training in bite from educational centers like Kois, Pankey, Dawson, or Clinical Mastery. Hoping that this never happens to you again!

There may be different reasons for debonding a veneer such as reduction style, veneer design (occlusal closure), veneer quality, cement type or bruxism. That is not possible to understand the root cause from distance. Therefore you better see a dentist asap.