Success rate of mini- and micro-implants used for orthodontic anchorage: a prospective clinical study.

OBJECTIVES: Whereas micro-implants have become a useful alternative as orthodontic anchorage elements in orthodontics, less is known about the clinical effectiveness of micro-implants. The aim of this prospective clinical study was to evaluate the success rate of micro-implants used for orthodontic anchorage.

MATERIAL AND METHODS: A total of 133 mini-implants (79 Abso Anchor, 54 Dual Top implants) placed in 49 patients to support orthodontic tooth movements were examined in the study. The majority of the implants were placed in the maxilla (82), followed by the vestibular (42) and lingual (nine) aspect of the mandible.

RESULTS: An overall cumulative survival rate of 86.8% (102/133) was found by Kaplan-Meier analysis. The failure rate between Dual Top implants (13%) and Abso Anchor implants (30.4%) differed significantly (P=0.0196; log-rank test). The cumulative failure rate of implants was found to be significantly higher when implants were placed in the lingual aspect of the mandible compared with the other localizations (P=0.0011; log-rank test). Clinical evaluation revealed successful dental movements when implants remained stable during the orthodontic therapy.

CONCLUSIONS: The present results confirm the effectiveness of orthodontic micro-implants used as anchorage elements.