Hello. Sir, u have got a big tooth decay between upper 1st and 2nd molars (6 & 7). The decay is deep in 7, which will need a root canal treatment. The decay in 6 is not very severe.
The decay cannot get filled by itself. U have to go for root canal treatment with 7 as the nerve of the tooth is involved because of decay. And u will need to get a filling done in 6.
Also, u have some interdental bone loss between 6 & 7 because of continuous food getting stuck. After the root canal treatment in 7 and filling in 6, u will have to get a crown done for tooth 7.
Next Steps
Whatever opinion your dentist has given, is correct. U must go ahead with the treatment to get relief from pain.