Background: Fixed orthodontic appliances (FOA) temporarily interfere with periodontal health of patients, as the appliance complicates oral hygiene. The use of aligners in orthodontic therapy increased strongly during the last decade. In the literature, the reports about effects of aligner treatment on oral hygiene and gingival conditions are scarce. This cross-sectional study evaluated oral hygiene and patient's satisfaction during orthodontic treatment of patients with FOA or Invisalign®.
Methods: 100 patients (FOA = 50, Invisalign® = 50) were included who underwent orthodontic treatment for more than 6 months. Clinical examinations were performed to evaluate patients' periodontal condition and were compared with clinical data at the beginning of the orthodontic treatment. Oral hygiene, patients' satisfaction and dietary habits were documented by a detailed questionnaire. For statistical analysis, the Mann-Whitney U-Test and Fisher's Exact Test were used; as multiple testing was applied, a Bonferroni correction was performed.
Results: At the time of clinical examinations, patients with FOA were in orthodontic therapy for 12.9 ± 7.2 months, whereas patients with Invisalign® were in orthodontic therapy for 12.6 ± 7.4 months. Significantly better gingival health conditions were recorded in Invisalign® patients (GI: 0.54 ± 0.50 for FOA versus 0.35 ± 0.34 for Invisalign®; SBI: 15.2 ± 7.6 for FOA versus 7.6 ± 4.1 for Invisalign®), whereas the amount of dental plaque was also less but not significantly different (API: 37.7 % ± 21.9 for FOA versus 27.8 % ± 24.6 for Invisalign®). The evaluation of the questionnaire showed greater patients' satisfaction in patients treated with Invisalign® than with FOA.
Conclusion: Patients treated with Invisalign® have a better periodontal health and greater satisfaction during orthodontic treatment than patients treated with FOA.