Lu Zhicen1, Xie Haifeng1, Zhang Feimin1, Zhang Huaiqin1, Chen Chen2. 1. Dept. of Prosthetics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China;Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing 210029, China. 2. Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing 210029, China;Dept. of Conservative Dentistry and Endodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China.
Abstract
OBJECTIVE: To analyze chemical mechanism of bonding improvement of zirconia via 10-methacryloyloxydecyl dihydrogen phosphate (MDP) conditioning. METHODS: Various models were created for tetragonal zirconia crystals, molecular MDP, and MDP complex, and tetragonal zirconia crystal. Thermodynamic methods were used to analyze configuration between MDP and tetragonal zirconia crystal through calculation of their Gibbs free energy values and equilibrium constants. RESULTS: Two potential configurations (double- and single-coordinate) may occur between MDP and ZrO2 crystal clusters. Thermodynamic calculations showed that -147.761 and -158.073 kJ·mol⁻¹ Gibbs free energy were required to form single- and double-coordinate configurations; their negative signs indicate that reactions for both configurations can occur. Equilibrium constant for single-coordinate configuration was 7.72×10²⁵, which was less than that of double-coordinate configuration (4.95×10²⁷), suggesting that the latter was more stable. CONCLUSIONS: MDP can spontaneously establish a double-coordinate configuration with zirconia. .
OBJECTIVE: To analyze chemical mechanism of bonding improvement of zirconia via 10-methacryloyloxydecyl dihydrogen phosphate (MDP) conditioning. METHODS: Various models were created for tetragonal zirconia crystals, molecular MDP, and MDP complex, and tetragonal zirconia crystal. Thermodynamic methods were used to analyze configuration between MDP and tetragonal zirconia crystal through calculation of their Gibbs free energy values and equilibrium constants. RESULTS: Two potential configurations (double- and single-coordinate) may occur between MDP and ZrO2 crystal clusters. Thermodynamic calculations showed that -147.761 and -158.073 kJ·mol⁻¹ Gibbs free energy were required to form single- and double-coordinate configurations; their negative signs indicate that reactions for both configurations can occur. Equilibrium constant for single-coordinate configuration was 7.72×10²⁵, which was less than that of double-coordinate configuration (4.95×10²⁷), suggesting that the latter was more stable. CONCLUSIONS:MDP can spontaneously establish a double-coordinate configuration with zirconia. .
Authors: Evaggelia Papia; Christel Larsson; Madeleine du Toit; Per Vult von Steyern Journal: J Biomed Mater Res B Appl Biomater Date: 2013-10-09 Impact factor: 3.368