Flexural properties of denture base resins subjected to long-term water immersion.
OBJECTIVE
The aim of this study was to investigate the flexural properties of denture base resins subjected to long-term water immersion.


METHODS
Four denture base resins (one conventional heat-processed, one microwave energy-processed and two pour-type autopolymerizing) were selected for this study. The specimens of each denture base material tested were fabricated according to the manufacturers' instructions (n = 10). The flexural properties of the denture base resins were measured according to ISO 20795-1. The ultimate flexural strength, the flexural strength at the proportional limit and the elastic modulus of the specimens were evaluated.


RESULTS
The ultimate flexural strengths of the heat-processed resin and the two pour-type autopolymerizing resins significantly decreased after 6 months water immersion. The flexural strength at the proportional limit of the heat-processed resin significantly decreased after 6 months water immersion, but the microwave energy-processed denture base resin and two pour-type autopolymerizing resins did not change after 6 months water immersion. The elastic moduli of the heat-processed resin, the microwave energy-processed denture base resin and one pour-type autopolymerizing resin significantly increased after 6 months water immersion.


CONCLUSIONS
The flexural properties of denture base resins significantly changed after long-term water immersion.
Division of Removable Prosthodontics, Fukuoka Dental College, Fukuoka, Japan. ytakaha@college.fdcnet.ac.jp
Yutaka
Y
Takahashi
Ippei
I
Hamanaka
Hiroshi
H
Shimizu
D000704:Analysis of Variance; D003778:Dentures; D008422:Materials Testing; D012117:Resins, Synthetic; D014867:Water
D012117:Resins, Synthetic; D014867:Water