RESUMEN
<p><b>OBJECTIVE</b>To synthesize and evaluate a novel injectable and water-swelling gingival displacement materials.</p><p><b>METHODS</b>A kind of water-swelling polymer, kaolin and aluminum chloride were mechanically mixed at certain ratio in water solution, resulting to a novel paste materials for gingival displacement. Then, its stability in aqueous solution and water swelling properties were evaluated in vitro. The effect on gingival displacement was evaluated by animal experiments in dogs. A commercial gingival displacement materials paste of Expasyl was used as control.</p><p><b>RESULTS</b>While contacting with water, the novel gingival displacement paste did not collapse, maintained its integrity structure, and could expand for adsorbing water. Animal experiments in dogs showed that the materials could lead to displace the gingival margins from the dental root surfaces.</p><p><b>CONCLUSION</b>The novel injectable and expanded gingival displacement material is efficient to retract free gingival margin with potential clinical application.</p>