Abstract: Objective　 To evaluate the effect of a silane coupling agent (γ-MPS) on the formation of 10-MDP-Ca salts. Methods　 The experimental primer was obtained by adding different weight (0%、5%、10%、15%) of γ-MPS in 10% 10-MDP solution. Silane solutions of different weight (5%、10%、15%) are also prepared. The primer reacted with hydroxyapatite (HAp) to obtain residual recants. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis（XRD） was performed to evaluate the formation of 10-MDP-Ca salts. Results　 Fourier transform infrared spectroscopy showed that the peak of methacryloxy carbonyl group of 10-MDP was detected in the residual recants after treatment with primer containing 10-MDP. After treatment with different weight of γ-MPS, there was no difference when comparing with the control group. X-ray diffraction results indicated that the residual recants were significantly different from that of the 10% 10-MDP group when 10% or 15%γ-MPS were added. Conclusions　10- MDP and HAp can form 10-MDP-Ca salts, while γ-MPS cannot react with HAp. 10% or 15% γ-MPS inhibited the formation of 10-MDP-Ca salts.

Key words: γ-MPS, 10-MDP, 10-MDP-Ca salts, fourier transform infrared spectroscopy, x-ray diffraction