Esterases affect the physical properties of materials used to seal the endodontic space

Materials used to seal the endodontic space are subjected to enzymatic degradative activities of body fluids and bacteria. Objectives. To assess effects of simulated human salivary, blood and bacterial esterases (SHSE) on physical properties of typical restorative material and root canal sealers. Methods. Specimens of set methacrylate-based resin composite (Bisfil (TM) 2B; RC), calcium-silicate sealer (EndoSequence (R); BC) or epoxy-resin sealer (AH-Plus (R); ER) were tested after up to 28 Days exposure to phosphate buffered saline (PBS) or SHSE, using ANSI/ADA-57:2000 and ISO-6876:2012. Results. Regardless of media, microhardness increased with time for BC remained unchanged for ER and decreased for RC (p < 0.05). SHSE moderated the increase for BC compared to PBS (28.0 +/- 4.8 vs. 38.1 +/- 7.9 KHN) at 7 Days, and enhanced the decrease for RC at 7 Days (55.6 +/- 7.1 vs. 66.3 +/- 6.5 KHN) and 28 Days (52.3 +/- 9.2 vs. 62.6 +/- 8.5 KHN). Compressive strength was enhanced only for BC by either media. BC expanded with time for both incubation conditions; SHSE moderated the expansion compared to PBS at 7 Days (0.026 +/- 0.01% vs. 0.049 +/- 0.007%). Shrinkage of ER was similar for both incubation media and was lower than that for RC (p < 0.05). Shrinkage of RC was enhanced by SHSE compared to PBS at 7 Days (0.5 +/- 0.07% vs. 0.38 +/- 0.08%). Weight loss was lowest for ER and highest for BC (p < 0.05). It was enhanced by SHSE compared to PBS for BC at 28 Days (2.40 +/- 0.2 vs. 2.96 +/- 0.19 W L%), and for RC at 7 Days (0.54 +/- 0.09 vs. 0.80 +/- 0.1 W L%). Significance. Simulated body fluids and bacterial esterases affected the physical properties of test materials, suggesting potential impacts on sealing ability and resistance to bacterial ingress, and to oth strength ultimately affecting their clinical performance. (C) 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.