Is there a specialized teeth whitening dental hospital in Gwangju?

My teeth are somewhat yellow, so I am currently studying about teeth whitening.

I recently purchased and am using a toothpaste that is said to be good for teeth whitening, but...

I don't think the effect is that good...ㅠㅠ

I want to try teeth whitening, but I can't.

Side effects or disadvantages of teeth whitening include

1) Teeth may feel sensitive - this is said to happen when the teeth are cracked.
2) Prohibit colored foods - It is said that foods like kimchi or coffee should be avoided...ㅠㅠ
3) Regularly perform teeth whitening - the cost doesn't seem to be affordable...ㅠㅠ

Teeth whitening should be done regularly, just like washing clothes that are dirty with detergent.

Please recommend a dentist in Gwangju Metropolitan City who specializes well in teeth whitening.