Is this a cavity?

[ch567ch]

A dentist told me I had a cavity while looking at my tooth xray, but he didn't seem very confident about it. He checked my tooth and said a bit more confidently that I did have a cavity.
But I still asked a second dentist, and showed him the xray, and he said I didn't have any cavity. He checked my teeth, and said confidently that I didn't have any cavity, and that what the previous dentist saw was probably a shadow or decalcification.
But because the first dentist still though I had a cavity, I am unsure who to believe. Thus, while looking at this xray, do you think I have a cavity? If so, in what square of the grid is it positioned at?
original: https://postimg.cc/2LzZmQh5
original with a grid!: https://postimg.cc/grGtS1Qv

 

[Dr M]

Good day

On the x-ray it doesn't look like you have any large cavities.
Keep in mind, a clinical exam with a x-ray, would give a more definite answer.

 

[honestdoc]

I agree with Dr M. Grid 30 may have an incipient (small) cavity in between. The image is not clear. I usually like to see multiple images to confirm. With small cavities that have not penetrated through the enamel, you don't need to fill them. I have 3 cavities bigger than that and have been watching them for more than 25 years.