My usual dentist is away on holidays so I saw a different younger dentist and I’m feeling a bit doubtful with her findings.
She said I had a couple of cavities and took some X-rays. I didn’t get a copy of the X-rays, but are they very obvious confirming a cavity or should I get a second opinion?
If you have doubts then yes, go ahead. You of course don't have to tell your dentist you sought a second opinion.
A cavity caught early and treated early is less expensive and less painful for you. Some people do leave it too late and cause extra problems for themselves. If a dentist said you need treatment then get a second opinion soon.