Invisalign is a system of clear aligners used by orthodontists to straighten teeth. These removable aligners are made of smooth BPA free plastic. They have proven to be one of the finest ways of treating simple orthodontic conditions since the aligners are invisible. It is easy to maintain oral hygiene with these aligners since a patient can remove them when cleaning teeth. The treatment duration may vary from 18 months to 24 months based on the condition. A series of aligners are custom-made for the patient and each pair should be replaced with another after every 2 weeks.