Need advise

I need an advise ,

4 weeks ago went to Dr.Well clinic in Chung Chen Rd Tienmu
Then Dr.Huang
said he found many cavities

then after 10 ! apointments he made root canal ,
and told that I need cram for 2 teeth ( each per 20.000+ 9000 some filling materials)
which even never pain before …
( he told that only after several apointments - he found that cavities too big )

I think he just spoil my good tooth

So How to find truth in such situation ?
Or where possible to complain for such Dr?

Hope to hear reply

Start by going to another dentist for a 2nd opinion, of course. Good luck!

Second Dr. said that possible in my case its should do any root canal
but due its alrady happen - then only cram choice.

SO I just want to know when possbile to go and compain for such hurmful
things ?