Changes in prosthetic screw stability because of misfit of implant-supported prostheses.
OBJECTIVE
The effect of two levels of prosthesis misfit on prosthetic screw stability was evaluated.


METHODS
Two levels of vertical discrepancies--100 and 175 microns--were introduced between an implant-supported complete denture and the terminal abutment. An implant-supported complete denture without vertical discrepancy served as a control. Cyclic load was delivered vertically on the cantilever portion of the prosthesis next to the terminal abutment for 48 hours for each trial. A total of seven sets of new screws were tested for each level of fit.


RESULTS
The results revealed significant prosthetic screw instability at both the 100- and 175-micron levels of discrepancy.


CONCLUSIONS
Vertical discrepancies of 100 and 175 microns introduced between an implant-supported fixed complete denture and the terminal abutment resulted in significant prosthetic screw instability.
al-Turki
Lulwa Ebrahim E
LE
Chai
John
J
Lautenschlager
Eugene P
EP
Hutten
Mark C
MC
D000704:Analysis of Variance; D000044:Dental Abutments; D017268:Dental Prosthesis Retention / Q000295:instrumentation*; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D006801:Humans; D017755:Prosthesis Fitting; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical; D019415:Torque