Assuming the whitening strip you have is of superior quality, one pair strip can give you whitening result that can last up to 6 months. It varies based on a lot of factors like diest, quality of whitening strip and others

Hello!

Hello It is not recommended to use Please visit the dentist for scaling

No matter whatever you use it’s not gonna give you permanent solution. It’s always temporary. Regarding if you want to use on a regular basis or at an interval it depends how frequently you want your teeth to stay bright. But all such things have post sensitivity problems which you should be aware of before using it. Though the sensitivity is minimal. However if you want to get a long lasting permanent solution visit a doctor who knows the art of doing laminates and veneers. It’s a myth if people say you veneers and laminates won’t last for long. Those are the longest lasting restoration inside our mouth provided if every protocol is being followed and proper case selection is done for the patient.