Fit of Implant Frameworks Fabricated by One-Piece Casting, Laser Welding, Soldering, and Electric Discharge Machining / 대한치과보철학회지

ABSTRACT

The purpose of this study was to measure and compare the strains produced by screw-tightening implant frameworks fabricated by five different fabrication methods;(1)one-piece cast using plastic sleeve,(2)one-piece cast using gold cylinder,(3)laser welding,(4)soldering,and (5)electrical discharge machining,and also to measure and compare the strains produced when the order of screw tightening was changed. A research model incorporating eighteen strain gages was made to measure the fit of implant frameworks in three dimensions.Three implants aligned in an arc were fixed on the top ends of the L-shape aluminum bars of the research model,and standard abutments were joined to the implants with abutment screws.Five types of implant framework were placed on the abutments and screwed by a torque wrench using 10 Ncm. Under the conditions of this study,the following conclusions were drawn 1.The electrical discharge machining group showed the smallest magnitude of strain,followed by the soldering group,the laser welding group,the one-piece cast group using gold cylinder,and the one-piece cast group using plastic sleeve.However,among the magnitude of strain for the remaining groups except the electrical discharge machining group,there were not significant differences. 2.When the order of screw tightening was changed,there were not significant differences in the magnitude of strain. 3.In comparison with the electrical discharge machining group,the laser welding group and the one-piece cast groups showed greater horizontal distortion and the soldering group showed greater horizontal and vertical distortion.