Some people think that if they get a cavity their tooth would hurt, however that is not always the case.  In fact a large majority of cavities are completely painless.  The reason for this is that the outer tooth enamel has no nerves. It is only when the cavity gets larger enough that it starts to enter the underlying dentin that the cavity may begin to feel sensitive.

Therefore waiting to see a dentist only when you have dental pain is not good advise. By the time you feel pain from a cavity you may also have larger dental issues to address. This is because the cavity may have spread to infect the dental pulp, necessitating a root canal procedure or an extraction to eliminate the infection.    With regular dental check ups a dentist will be able to spot small cavities. It is far better to treat a small cavity than to wait until you have symptoms like pain.