Objective: the aim of this study was to evaluate the retention of the copy post in endodontically
treated teeth cemented by three different types of cement for over-denture abutments: An in-vitro
study.
Method: nine recently extracted human mandibular canines and premolars were endodontically
treated and randomly divided into three groups of three specimens each. Group I: the copy posts
were cemented by zinc phosphate cement (ZPC), Group II: the copy posts were cemented by Fuji
cement (FC) and Group III: the copy posts cemented by core x composite cement (CXFC).
Universal Testing Machine was used for retention test of copy posts. The data was collected and
statistically analyzed by one way ANOVA with Tukey’s post hoc multiple comparison tests.
Result: By compression of retentive forces between different types of cement, The highest
retentive value was shown in combination of the copy post with zinc phosphate cement with p
value less than 0.05 (p =0.03), followed by fuji cement while the core X flow cement showed
The lowest retentive value.
Conclusion: within the limitation of the present study, the selection of proper cement is critical
for success and survival of the core post system to support over-denture, and the ZPC showed the
highest retentive value in combine with core post in compare with FC and CX FC.
Keywords: Over-denture, Metal Copy Post, Luting cement, Retention test