Effects of echistatin and an RGD peptide on orthodontic tooth movement

We tested whether orthodontic tooth movement (OTM) could be blocked by local administration of echistatin or an arginine-glycine-aspartic acid (RGD) peptide, agents known to perturb bone remodeling, adjacent to maxillary molars in rats. These molecules were incorporated into ethylene-vinyl acetate (ELVAX), a non-biodegradable, sustained-release polymer. In vitro experiments showed that the echistatin and RGD peptide were released from ELVAX in active forms at levels sufficient to disrupt osteoclasts. Biotinylated RGD peptide was released from ELVAX into the PDL after surgical implantation. ELVAX loaded with either RGD peptide or echistatin and surgically implanted next to the maxillary molars inhibited orthodontic tooth movement (p < 0.01). The RGD peptide also reduced molar drift (p < 0.05). This study shows the feasibility of using ELVAX to deliver integrin inhibitors adjacent to teeth to limit local tooth movement in response to orthodontic forces.