I'm guessing your body had that reaction from the Antibiotics because you had a systemic bacterial infection of some sort kind of like mine with whipples disease it sounds like it gave you a pretty strong herx-reaction. Many dentists offices are breading grounds for bacteria especially actinobacteria that is commonly found in our saliva and stool. I had a pretty strong brain herx-reaction today from the tspn of pine needle oil I took. Our bodies are full of bacteria from the food we eat especially from fruits and vegetables.