Hi, u have to get a round of cleaning done for ur teeth ,which will help in getting rid of those deposits and help u get back ur normal gum form.about the  yellowish discoloration there are many ways to handle it like bleaching, laminates, ceramic caps,the cost varies for each treatment and also depends on the intensity and the cause of the discoloration,so it's better if u discuss with ur doctor when u going to get ur teeth cleaned.

Hello.  Yellow teeth are due to many reasons. 1) If they are due to tarter then you should go for teeth cleaning. 2) sometimes some people have naturally yellow teeth then nothing has to be done and still if you want white teeth then go for teeth bleaching. 3) If teeth yellowish are due to teeth wear then you should go for Ceramic veneers.