Fracture surface characteristics of damaged acrylic-resin-based dentures as analysed by SEM-replica technique.

The aim of this study was to determine some characteristics of the fracture surface of an acrylic resin denture. For this purpose, five complete upper dentures and two complete lower dentures that had fractured into two pieces were collected, the fracture surfaces were duplicated with the SEM-replica technique and duplicated surfaces were investigated with a scanning electron microscope. The reproducibility of the SEM-replica technique was tested by comparing one original sample surface and its replica surface of the same area. The SEM-photomicrographs revealed a series of fine striations in the fracture surfaces of both the upper and lower dentures perpendicularly orientated to the direction of the fracture propagation. A smooth area on the fracture surface was assumed to indicate a slow fatigue fracture process, and a rougher area fracturing with increased velocity.