Enhancement of orthodontic anchorage and retention by the local injection of strontium: An experimental study in rats.

Objectives: To examine the clinical and histological effects of locally injected strontium on the anchoring unit of a rat model of an experimental relapsed tooth movement.

Materials And Methods: Thirty-six 10-week-old male Wister rats were randomly divided into two groups of 18 animals that were then randomly divided into three subgroups of six animals corresponding to three observation periods: T1 = 1 week, T2 = 2 weeks, and T3 = 3 weeks. In the first experiment, both the right and left maxillary first molars were moved buccally with a standardized expansive spring.