Legal Question in Personal Injury in Illinois

They could be. Here's what I would do:

1) Save the sunflower seed that caused your injury. Was there anything unusual about it? For instance, if it contained a piece of metal, that may be very problematic for them. If it was a typical sunflower seed, and you ate it in a manner that caused your injury, you will probably lose.

2) Request all of your medical records. Ask your dentist how much it will cost to fix the chipped tooth, and whether there is any other injury.

Retain an attorney to send them a demand letter and try to get you compensation.

On your facts, there is simply no liability.