You can use it again and again for other lightning payments though, as long as you have enough incoming/outgoing liquidity.
You have to close the channel and wait for a couple of confirmations before it can be used for "regular transactions" again.
But if we reach the time when everyone is using LN, closing your channels might not be considerable since you can just send and receive BTC through LN.
Don't say "normal bitcoin blochchain", it's just bitcoin's blockchain or as others said: "main chain"; LN is a network, not another blockchain.