Clear aligners donít hurt. However, itís fairly common to experience some tenderness or sensitivity that will occur when the aligner is first fitted and when aligner trays are changed. For most, discomfort is minor and will subside within one to two weeks, while others may feel discomfort throughout treatment. However, the more you wear the aligner the more comfortable they become. Sores and irritation are possible but really donít occur that often.
The aligners can also sometimes temporarily affect your speech. But most people adapt quickly to wearing the aligners and your speech would rarely be impaired for an extended period of time. You may also experience a temporary increase in salivation or dryness of the mouth.
Clear aligners are significantly less painful than metal braces. Most people report discomfort for the first few days of wearing the trays and some tenderness, but when compared to the agony of metal braces, Invisalign wins by being less painful. One of the pains of braces comes with eating.