Objective To evaluate periodontal health in patients during treatment with invisalign, and to compare periodontal indices in patient with conventional brackets and a series of invisible aligners. Methods Forty-five cases were randomly selected. The range for the pre-treatment age was 20 to 40 years. Forty-five patients were divided into 2 groups according to the type of appliance, which were 25 patients with conventional pre-adjusted brackets in group A and 20 patients with invisible aligners in group B. Periodontal indices, including gingival index（GI）, sulcus probing depth（SPD）, sulcus bleeding index（SBI）, plaque index（PLI）, were examined in both groups at three control visits （1st, 3rd, 6th month respective） by the same periodontal specialist. Then, compared and analysed the impacts of two appliances on the periodontal health of the patients. Results Compared with pretreatment, there was significant difference in all periodontal indices in group A except SPD, while there was no significant difference in all periodontal indices in group B during the orthodontic treatment. There was no significant difference between group A and group B during the orthodontic treatment except PLI. Conclusion Invisalign appliance could not have obvious influence on the patient’s periodontal health. Although invisialign appliance is more beneficial for the patient to keep oral hygiene, there is no significant difference on the patient’s periodontal health.
