The effect of water sorption on the ultimate transverse strength of a heat-cured denture base resin relined with four different direct denture reline materials was investigated. The relined specimens weretested after 1 day and 1 month of water immersion. It was found that prolonged duration of water immersionand an increase in the thickness of the reline material significantly (p<0.01) decreased the ultimate transversestrength of specimens relined with powder-liquid type direct reline materials. Specimens relined with pastetype reline material did not change the ultimate transverse strength after 1 month of water immersionsignificantly.
