Why does dental caries hurt?

First of all, if the caries is deep, it may irritate the dental pulp, and the dental pulp may bleed, and there is a sensitive pain phenomenon. At this time, we will normally use zinc oxide to appease the dental nerve. Zinc oxide to appease the dental nerve may not show obvious pain, but may also show obvious pain. If it shows obvious pain, it is very likely that there is pulp penetration, but we did not find it, it is also possible that this tooth is already chronic pulpitis, so it shows pain, this time it needs root canal treatment, that is to say, it needs to kill nerves.