OBJECTIVEA method for 3D-data acquisition of partially edentulous cast was introduced to lay the foundation for reconstructing 3D digital model of a partially edentulous cast and studying computer aided design (CAD) to a removable partial denture framework.

METHODSUsing projection system controlled by a computer, four frames of sinusoidal fringe pattern at pi/2 intervals were projected onto the surface of partially edentulous cast consecutively within 0.4 second. Deformed fringe patterns modulated by the surface height of the cast were recorded by a digital camera. The phase value with the height information was demodulated with phase-shifting method. The transition from the unwrapped phase to the height of the points on the cast was performed with triangulation method. The multiview 3D data was integrated automatically to obtain the complete 3D profile data and the 3D digital model of the partially edentulous cast was reconstructed.

RESULTSDense and complete points-cloud data was achieved without scanning blind zone basically. The anatomic structure of reconstructed 3D digital model was sharp and clear.

CONCLUSIONAs an alternative for acquiring 3D data of partially edentulous cast, this method presented here with high precision and high speed meets the need for the subsequent 3D design to removable partial denture framework.