Go to ABOTA.ORG to find a plaintiffs medical malpractice attorney in your area. You will need to have another dentist look at the veneers and provide expert testimony that the care you received was below the standard of care. You should also file a complaint with the dentistry board in California.
This is something you should discuss with an attorney. You may be able to prepare a waiver that can be signed by everyone participating in the potluck that they understand the food is being supplied by others and recognize and waive all liability for any sickness as to the church. It would need to be whats called an "express waiver" and may not be an option in your state. That is why you need to consult an attorney.
That will likely not translate to much money in the Calif Work Comp system. You must consult with a work comp atty in Calif. to determine if the rating is accurate and then the value of your claim. I would refer you to Thomas F Martin. You can reach him at 714-547-5025.
There are companies who specialize in cleaning up and removing negative posts about individuals. I suggest contacting one first. Just google 'reputation repair on the internet' to find one suitable for you.