hello,
this is a very tough question, firstly the time and cost depends on the amount of build and stains you have in your mouth. A well equipped dental clinic where all the basic precautions are being taken to prevent cross infection, instruments are being autoclaved and good quality equipments are being used the charges will be on little higher side in comparison to gen. hospitals. But as it is said health is above wealth. there are some hospitals charging with eco charges and good services as well so you have to decide
Next Steps
visit your dentist and get scaling and polishing done, get it done every 6 months to keep your oral hygiene at best and check
Health Tips
brush twicw daily using fluoridated toothpaste and soft toothbrush, floss your teeth and use chlorhexidine mouthwash at least once a day.