[Effect of Rhizoma Drynariae and Salvia on alveolar bone density of rats with orthodontic tooth movement].

Purpose: To detect and compare the effects of traditional Chinese drugs, Rhizoma Drynariae and Salvia, on the density of alveolar bones of rats through animal models for molar movement.

Methods: 72 female, 8-week-old SPF Wistar rats were selected to establish the animal models for orthodontic tooth movement. The rats were randomly divided into 3 groups: Rhizoma Drynariae group, Salvia group and normal saline(NS) group. Each group had 24 rats. Rhizoma Drynariae asperoides decoction (6 g/kg), Salvia decoction (6 g/kg) and 3 mL 0.9% NS were drenched daily to the rats in the Rhizoma Drynariae group, the Salvia group and the NS group, respectively. Stability of the appliances was checked every day and the applied force was raised by adjusting the springs every 7 days. The rats were executed in batch on the 7th, 14th, 21st, 28th day by removing the skulls. Then the movement distance of the first maxillary tooth and the alveolar bone density were measured. All statistical analysis was performed using SPSS 18.0 software package.

Results: Teeth movements in the Rhizoma Drynariae group and the Salvia group was greater than the NS group (P<0.05) while no significant difference (P>0.05) was found between the first two ones. Though alveolar bone density showed a trend to decrease in all 3 groups, the Rhizoma Drynariae and Salvia groups decreased slowly (P<0.05) and no significance was discovered between the two group (P>0.05).

Conclusions: Rhizoma Drynariae and Salvia can both slow the alveolar bone density decrease and accelerate the orthodontic tooth movement.