Why would Benzocaine make a toothache hurt worse?

I have a cracked wisdom tooth which began hurting very badly a couple of nights ago. So, I bought some Oragel to put on it, which has always worked in the past. Not this time, I may as well have put straight sugar on it, it hurt so bad, I started crying. I ran to the sink and washed it out, but it still made my toothache much worse than it had originally been. Why would it make the tooth hurt worse instead of numbing it?

Why would Benzocaine make a toothache hurt worse?
If the tooth is cracked you need it taken out. It's probably because it's been cracked over a period of time now and the nerve is getting infected. If that nerve is exposed and you put something on it, it will hurt. If the orajel was cold or hot it could have upset the nerve also. Get it taken out! It won't get better.
Reply:It sounds like the nerve is exposed and you probably have an abscess which has caused the onset of pain. An abscess is and infection and usually occurs when the nerve is damaged. If the nerve is exposed anything will set it off and make it hurt worse. Also if there is infection it may prevent numbing.





If your dentist did not put you on an antibiotic you should contact them again and let them how bad the pain is. If there is infection you may not numb very well for the extraction.
Reply:First of all, I'm sorry for your pain and hope that it's resolved soon. Topical Benzocaine is meant to be applied to mucosal surfaces so that it can be absorbed and provide peripheral anesthesia. The pulp tissue in a cracked tooth may already be hypersensitive and direct contact by the anesthetic was too much of an overload. The fact that the nerve responded confirms that the pulp tissue is vital, not abscessed as has been suggested. Do everything you can to kepp the crack from being exposed to noxious environmental agents. Perhaps your dentist could give you some orthodontic wax tobe carefully placed over the cracked area until the tooth is extracted. Good luck to you!
Reply:Most likely it is the temperature of the benzocaine that you placed that made the tooth so angry. The middle layer of teeth are composed of something called dentin. Dentin is composed of a bunch of tiny straws that are fluid filled. These straws lead directly to the nerve. Temperature change causes liquids to expand or shrink. That change in pressure causes pain on the nerve. Kina like when you put water into ice trays in the freezer, they come out as ice cubes but they are bigger, or when you place a soda in the freezer and it bursts when it freezes. Probly the bes thing you could do is to get some orthodontic wax and place over the tooth. It may hurt for a second but should help prevent transmition of changes in pressure until you get to the dentist.