Do dentists in Thailand do this, I mean to go under gums and clean out tartar, buildup with a special hook tool??

I am 36 yo and dentists in my country never do this procedure. My dentist laughed when I told him about this.

In America this is very usual process, can somebody explain this in more details?

Root planing and scaling is done here as in every country that I am aware of for those needing it. Can't imagine where they would not do this common procedure "otherwise known as conventional periodontal therapy".

http://en.wikipedia....nd_root_planing

In Slovenia, I have one of the best dentists, he never did this on me, I have never have that done in my life, they dont do that

They would not do unless you need it - most people don't. My first experience of having it done in the USA was from a doctor recently arrived from eastern Europe and that was in 1990 so would think it must be known there.

Yes, every dentist I've been to in Thailand does that.

does it hurt? is it necessary?

I've had a number of dental cleanings done here in Thailand. In my experience, the "normal" cleaning is done using some sort of ultrasonic tool, dental floss, and also polishing. The dentists normally do not do the sort of scraping and "deep" under the gums cleaning that the OP is referring to. To get that type of dental cleaning that includes "scaling and root planing" you need to specifically request it.

I recommend that you go to the dental office in person to make your appointment and take the time to make clear (politely and patiently!) what kind of cleaning you want done. Use terms like "root planing" and "periodontal cleaning". They will then schedule the additional time that it will take to do the type of cleaning you want done. I've done it this way and it worked out well.

I try to do it once every half year.

It cost 500 baht at Kitipoi clinic on pattaya tai,

between tuc kom & the temple, on the same side as the temple

I went to local densits today, she said I dont need cleaning,I dont have any tartar, I never have done ultrasound before, but I need some whitening on my teeth.

I saw crest whitening strips, do they carry them in Thailand or something similiar?

Crest does not really work. The best whitening is said to be a take-home whitening. It takes longer than laser but gives better results. I went to my dentist and had the whitening trays custom-made for my teeth. She gave me whitening gel and i wore those trays filled with the gel for like 5 consecutive nights and my teeth were like white white already.