Analysis of implant strain value exerted using different screw tightening protocols in screw-retained 3-unit prostheses / 대한치과보철학회지

ABSTRACT

Purpose@#The purpose of this study was to measure and compare the strain value exerted on the cervical area using different screw tightening protocols in implant-supported, screw-retained 3-unit prostheses. @*Materials and methods@#Strain gauges were attached to four implants two external and two internal. Thereafter, two study model were designed each type using acrylic resin. CAD-CAM was used to design hex and nonhex abutments for each group (EH, ENH, IH, and INH group) and Screw-cement-retained prostheses were also designed using a nonprecious base metal. Abutment was fixed with 10 Ncm torque, and the prosthesis was cemented. Screws were fixed with 30 Ncm torque using different three protocols. After 5 min, the strain gauge level was measured, and group analysis was performed (α=.05). @*Results@#External group showed significantly lower strain values than internal group and the EH group showed significantly lower strain values than the ENH group (P.05). The IH group exhibited significantly higher strain values than the INH group and the IH group showed a significant difference in strain values based on the types of screw tightening protocols used (P<.05). @*Conclusion@#There was no significant effect on the external type in the implant-supported, screw-retained prostheses. However, strain values were high in the internal type, and the types of screw tightening protocol significantly affected these implants.