Definitely dear,as the age advances it is quite normal to change the colour of enamel (outer covering)of tooth,so if u want make it to white again,there is a treatment procedure called bleaching .there r 2 types of bleaching-office and home ,cost of both depend upon the bleaching kit used.Carbamide peroxide is use in most professional bleaching kit.Approximately it costs anything between 1500 to 3000.It has some side effects if done frequently so plz do it once in 2 years
Next Steps
Visit ur dentist and get the bleaching done.
Health Tips
If u want to make the teeth whiter,by some safer and natural way u can contact me here on practo paid consultation.Regards!