You can not send Dentacoin tokens directly to your bank accounts as most banks do not accept cryptocurrencies yet. First, you need to exchange your Dentacoin tokens on a platform, then withdraw from there. Note that if you received your DCN tokens as rewards from Dentacoin platforms - DentaVox and TrustedReviews or Dentacoin Assurance after 24/01/2022, your DCN tokens are on Optimism Network. Before sending them to an exchange platform, you have to swap them to DCN on Ethereum Mainnet as exchanges, except Uniswap, do not support Optimism Mainnet yet. Follow the steps here.
Then, pick an exchange platform where Dentacoin is listed: https://dentacoin.com/traders
In most cases, you will have to create an account on the exchange platform. Once you do this, you can find the DCN deposit address by selecting DCN (Dentacoin) currency. Note that this address is only for DCN on Ethereum Mainnet and depositing DCN from Optimism will result in loss of your assets. Sending the tokens to the exchange means that you are going to make a transaction on the Ethereum blockchain. As for all tokens on Ethereum, the transaction is processed against the "gas fee" in ETH which goes to the miners on the blockchain.
When you deposit DCN on Ethereum Mainnet to your account on the exchange platform, you will be able to convert it to USDT or ETH. Finally, you can exchange the USDT/ETH to the national currency and withdraw.