title: Enzymatic degradation of BISGMA/TEGDMA-polymers causing decreased microhardness and greater wear in vitro.
abstract: The microhardness of the surfaces of BISGMA/TEGDMA-polymers decreased after treatment with pork liver esterase for 48 h in concentrations greater than or equal to 0.05 U/ml. This softening effect on BISGMA/TEGDMA-polymer surfaces was also shown as an increased wear rate of the polymers in the presence of esterase measured by a laboratory abrasion method. In this method, polymer cylinders were vigorously shaken in an aqueous slurry containing abrasive particles. The shaking was performed for 3 s followed by a rest period of either 100 or 200 s. This was repeated for 24 h. A greater mean loss of weight of the cylinders was measured when esterase was present in the slurry and the loss of weight increased significantly from 6.7% to 23.8% (P less than 0.001) when the rest period was increased from 100 s to 200 s. The results indicate that enzymatic hydrolytic activity in the mouth will contribute to a breakdown of composite resin fillings.
authors: Department of Dental Materials & Technology, Royal Dental College, Copenhagen, Denmark.
authors: M
authors: M
authors: Freund
authors: E C
authors: EC
authors: Munksgaard
mesh_terms: D000179:Acrylates; D017438:Bisphenol A-Glycidyl Methacrylate; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003188:Composite Resins; D004950:Esterases; D006244:Hardness; D008422:Materials Testing / Q000379:methods; D008689:Methacrylates; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000179:Acrylates; D003188:Composite Resins; D008689:Methacrylates; D011109:Polymethacrylic Acids; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D004950:Esterases