The influence of different pH of saliva and thermal cycling on the adaptation of different denture base materials

Abstract EN

Background: The difference in the adaptation of denture bases processed from heat cure acrylic, light cure acrylic and nylon materials and the effect of artificial accelerated aging (thermal cycling and pH) on the adaptation was studied.

Materials and methods: One hundred eighty stone cast were prepared and assigned into 3 main groups according to the denture base material that processed on them(heat cure, light cure, nylon), each denture base and its cast was sectioned at posterior palatal border and the gap between the denture base and the cast was measured using digital microscope.

Half of each group exposed to thermal cycling (2000 cycle) between (5 C-55 C ) 30 second in each bath then the adaptation was evaluated again.

All denture bases were stored in artificial saliva of different pH (5.7, 7,8.3) at 37 C for 30 days, then the adaptation was measured again.

Results and discussions: The results showed that the adaptation of heat cure acrylic was better than light cure and nylon before and after aging process.

The nylon showed the poorest adaptation.

Thermal cycling decreases the adaptation of all denture bases.

Variation of pH effected the adaptation of heat cure and light cure denture bases and did not affect the adaptation of nylon.