RESUMO
OBJECTIVE: The objectives of this study were to evaluate the effect of a CAD/CAM nickel-titanium retainer on the stability of mandibular anterior teeth and periodontal health and to compare it with other retainers. SETTING/SAMPLE POPULATION: Sixty participants from both genders who had irregularities prior to orthodontic therapy and who had been treated with full-fixed appliance mechanotherapy were included in the study and randomly allocated into four groups: CAD/CAM NiTi, multi-stranded stainless steel, single-stranded nickel-free titanium and vacuum-formed removable retainer groups. The mean age of the participants at the end of the treatment was approximately 20 years. MATERIALS AND METHODS: Digital impressions were taken for all participants at three different times: immediately (T0 ), three months (T1 ) and six months (T2 ) after treatment. Irregularity index, inter-canine and inter-molar width, and arch length were recorded using software. Additionally, a full periodontal assessment was carried out at T2 . RESULTS: During the follow-ups, all groups showed some relapse in the lower anterior teeth. No statistical significance was found intergroup in terms of all measured values. Within the multi-stranded group, inter-canine width had decreased by 0.10 mm with a statistical significance (P = .048). An additional statistical significance with P = .045 was found within the single-stranded group regarding the increased arch length. The periodontal assessment results of the mandibular anterior teeth between groups did not show clinically significant differences. CONCLUSION: No statistical significance was found between the CAD/CAM retainer and other retainers regarding the clinical failure rate. Less plaque accumulation and gingival inflammation were observed in the CAD/CAM NiTi retainer group.