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                        ABSTRACT
 
Background &Aim: Wear of acrylic teeth after passing years is still one of the main problems in dentistry that may lead to loss of chewing function, decrease of facial vertical height and unpleasant smile.This study aimed to evaluate the comparison of wear resistance of President &Ivoclar teeth against natural teeth.
Materials &Methods: In this Experimental Study, 64 samples of second premolar teeth that included 24 upper & lower second premolar of President teeth and 24 upper & lower second premolar of Ivoclar teeth and 16 upper & lower natural teeth, were included. The samples divided into 6 groups (5 case and 1 control), Each of 5 case groups included 12 samples, and the control group included 4 samples. After that, 3D images of each samples were provided by lab 3D scanner and then all of the samples (case and control) were put in the incubator (37°c ) for 24h.  After that, they were put in thermocycler After these processes, samples were scanned for the second time.Finally, 3D scans were superimposed.In the comparison of difference between samples volume ,Repeated Measure ANOVA Test, was used.
Results: after wear procedure with chewing stimulator, control group (natural teeth) had less wear vs president and ivoclar teeth, significantly CP<0.05). But President& Ivoclar teeth had not significant difference when they against each other (p>0.05). President  & Ivoclar teeth when against to the natural teeth had more wear vs when they put against each other (p<0.05).
Conclusions: It seems, wear of artificial teeth was more when they put against natural teeth. But there was not different between president and Ivoclar teeth.