A single material aligner system with the same thickness for all aligners results in forces that can sometimes be too much for individual teeth, leading to an increased chance of root resorption and unpredictable movements. In TrioClear, a combination of 1 soft and 1 hard aligners contribute around 0.6mm tooth movement. The use of a soft aligner to start every sequence of movement helps to ensure that forces initially expressed are low, before finishing up the final movement with a hard aligner. This principle of alternating between soft and hard aligners ensures a perfect range of orthodontic forces. The principle of this light force and then subsequent force reactivation might be compared with the principle of leveling and alignment in fixed appliance therapy. This unique Progressive Force Concept has been proven to make orthodontic teeth movements very predictable as you will also experience.