Application of Polyethylene Terephthalate as a Denture Base Material for Manufacturing Temporary Removable Complete Dentures

Abstract

The mechanical properties of both polymethyl methacrylate (PMMA) and polyethylene terephthate (PET) were examined in tensile and three-point bending tests, as well as their bond and interlayer shear strengths were assessed. The results obtained were employed in computer simulation of mechanical loading of temporary removable complete dentures (TRCDs). It was shown that the variations of the elastic moduli of the dental materials studied did not exceed 15.6%; the ultimate strength of PET was higher than that of PMMA by ~2.2 times in tension and by ~1.9 times in bending. Elongation at break was greater for the PET specimens than those for the PMMA ones by ~2.3 times in tension and by ~3.1 times in bending. Computer simulation has shown that when the load was applied at the angle of 90°, the tooth fractured in all cases. Stresses were much lower in the denture base concerning the critical levels. Therefore, the adhesion conditions considered did not affect the pattern of their failure, and the critical load was the same for both denture base materials. When the load was applied to canines at the angle of 45°, the critical load was below the specified level of 100 N in the PMMA denture base due to the peculiarities of TRCD design and the lower strength of PMMA. When both canines and incisors were loaded at the angle of 45°, the PET denture base could withstand the greater critical load than the PMMA one. Both mechanical tests and computer simulation results enabled to conclude that PET is the prospect denture base material for the manufacture of TRCDs and dental orthopedic treatment.