subcutaneous connective tissue reactions to various endodontic biomaterials: an animal study

background and aims. biocompatibility of root-end filling materials is a matter of debate. the aim of this study was to compare the biocompatibility of a variety of commercial proroot wmta cements and a resin-based cement (geristore®) with different ph values of setting reaction and different aluminum contents, implanted into the subcutaneous connective tissue of rats at various time intervals. materials and methods. fifty sprague-dawley rats were used in this study. polyethylene tubes were filled with angelus wmta, proroot wmta, bioaggregate, and geristore. empty control tubes were implanted into subcutaneous tissues and harvested at 7-, 14-, 28- and 60-day intervals. tissue sections of 5 μm were stained with hematoxylin and eosin and observed under a light microscope. inflammatory reactions were categorized as 0, none (without inflammatory cells); 1, mild (inflammatory cells ≤25); 2, moderate (25–125 inflammatory cells); and 3, severe (>125 inflammatory cells). statistical analysis was performed with kruskal-wallis and mann whitney u tests. results. proroot wmta and angelus elicited significantly less inflammation than other materials (p< 0.05). after 7 days, however, all the materials induced significantly more inflammation than the controls (p< 0.05). angelus-mta group exhibited no significant differences from the bioaggregate group (p=0.15); however, proroot wmta elicited significantly less inflammation than bioaggregate (p=0.02). geristore induced significantly more inflammation than other groups (p< 0.05). conclusion. geristore induced an inflammatory response higher than proroot wmta; therefore, it is not recommended for clinical use.