Root damage and repair in patients with temporary skeletal anchorage devices

Introduction The aim of this study was to evaluate the reparative potential of cementum histologically after intentional root contact with a temporary skeletal anchorage device. Methods Seventeen patients (8 male, 9 female; mean age, 16.2 years; range, 13.5-21.6 years) who were scheduled for extraction of 4 first premolars as part of their orthodontic treatment participated in this study. The roots of the premolars were intentionally injured with a temporary skeletal anchorage device. The teeth were extracted at 4, 8, or 12 weeks after the injury. Root contact with the temporary skeletal anchorage device was confirmed by using a stereomicroscope. Histologic samples were prepared. Demineralized serial sections were stained with eosin and hematoxylin, and cementum repair was assessed histomorphometrically. Results Despite varying depths of the injuries, including involvement of dentin, reparative cementum formation was observed in all sections. Healing cementum was almost exclusively of the cellular type; 70% of all the teeth exhibited good repair by the end of week 12. Conclusions This study established that healing of cementum takes place after an injury with a temporary skeletal anchorage device, and it is a time-dependent phenomenon.