(31)P solid-state MAS-NMR spectroscopy of the compounds that form in phosphate-bonded dental casting investment materials during setting.

Objectives: To use (31)P solid-state MAS-NMR to determine which compounds form in phosphate-bonded dental casting investment material during setting, when the ambient temperature is altered. To determine whether they differ in material originating at the center of the mix from material that adheres to the mixing bowl wall.

Methods: (1)H high powered decoupled (HPDC) and (1)H cross polarized (CP) (31)P solid-state MAS-NMR spectroscopy were used at a resonance frequency of 121.