What can u say about plastic retainer to align the teeth? is it effective? by the way, it has 3 types from soft to the hardest one and should be worn mostly at night while sleeping?

Moving teeth using plastic aligners is better accomplished when being treated by a dentist. Orthodontics is not a DIY endeavour. Yes, plastic aligners do work for many malocclusions but cannot always replace traditional wires and brackets. They are worn all the time, except when eating. Aberrant forces can damage your teeth and bony support.

Ineffective & dangerous. Part-time treatment fails. Removable appliances have to be worn at least 22 hours per day to achieve even a modicum of tooth movement. Removable appliances will not treat skeletal problems. A one-size-fits-all appliance will probably make things worse. If you want effective, not harmful, safe care, see a fully qualified specialist in Orthodontics. You get what you pay for