Microwave And Water Bath Polymerization Methods On The Precision And Physical Properties Of Resin Denture Base Denture

Objective To evaluate the effect of microwave polymerization and water-bath heat polymerization on accuracy and physical properties of denture base resin.Methods①The study is to compare the difference of denture base resin cured by microwave polymerization and water-bath heat polymerization.The dimensional accuracy between the posterior border of upper complete denture and standardized cast at five different positions was measured by digital microscope.②Specimens with 64mmxxxxxxx 10mm×2.5mm are made for measuring flexural strength and flexural modulus by electronic universal test machine.③Specimens with 60mm×4mm×2mm are made for measuring tensile strength by electronic universal test machine.④Surface roughness and hardness are mesured on 20mm×20mm×2.5mm specimens with surface roughness tester and Rockwell Hardness Tester.Results①The posterior border gaps between the upper complete denture and standardized cast was 141±78/μm and 147±74μm,respectively cured by two methods.No statistical difference was found between the two groups(P>0.05).②The flexural strength of denture base resin cured by the two methods is 84.24±17.65Mpa and 81.60±14.04Mpa,andflexural modulus,1859.52±104.96Mpa and 1815.32±97.76Mpa, and there is no statistical difference between the two groups(P>0.05).③Tensile strength is 49.77±1.53 Mpa and 50.08±1.41 Mpa respectively,and no statistical difference(P>0.05).④Surface roughness is 0.25±0.02μm and 0.26±0.03μm,and hardness is 39.9±0.9 and 39.8±0.6,and there is no statistical difference between the two groups(P>0.05).Conclusions There is no significal difference in the accuracy,flexural strength, flexural modulus,tensile strength,surface roughness and hardness cured by microwave polymerization and by water-bath heat polymerization,but the time that microwave polymerization takes is shorter than that by water-bath heat polymerization.