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Comparison of conventional and resin‐modified glass–ionomer luting cements in the retention of post‐crowns by fatigue loading
Author(s) -
Christina A. Mitchell,
John Orr
Publication year - 1998
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1046/j.1365-2842.1998.00287.x
Subject(s) - glass ionomer cement , materials science , composite material , cement , dentistry , medicine
Fatigue testing may be used for in vitro evaluation of luting cements, allowing comparison of materials under controlled conditions. It is recognized that glass–ionomer cements are materials which are susceptible to microcracking, even during curing prior to load application, and their failure can be related to crack propagation. The aim of this study was to compare the retention of post‐crowns cemented with conventional and resin‐modified glass–ionomer cements, the latter having significantly greater fracture toughness, under cyclic loads which are representative of physiological service. A custom‐designed fatigue machine was used for three tests each comprising 18 specimens in a modified randomized complete block programme. Correlation of load amplitude to endurance was low, as expected from static test experience, but cement comparison was made through Kaplan‐Meier survival and cumulative hazard functions. Differences in the performance of the cements were indicated, but were not statistically significant in this study, although analysis by Cox’s proportional hazards model indicated that significance may be gained by a larger study.