Retentive Properties of Re-activated Temporary Cements

Methods: Three groups of 10 provisional crowns (n=30) were luted individually to a prepared tooth with IRM, TempBond, or RelyX Temp E. A tensile force was applied with a universal testing machine at a speed of 5 mm/min to dislodge the crowns. One drop of eugenol was incorporated into the residual cement prior to the re-cementation of each crown. The crowns were then subjected to a second removal test. Each crown was then re-cemented a second time following the same protocol and subjected to the third removal test. Results were analyzed with ANOVA followed by Tukey's HSD test. A p<.05 was considered significant.

Results: Crowns cemented with IRM exhibited significantly higher load to dislodgment values initially (6.99 ± 3.23 Kg) and even after reactivation and re-cementation (6.86 ± 2.73) than those obtained from crowns initially cemented with RelyX Temp E (2.57 ± 0.66) or reactivated TempBond (1.91 ± 0.77). Initial cementation with TempBond provided load to dislodgement values that were not significantly different from those crowns cemented with IRM (7.65 ± 3.17). (F= 19.668, p<0.001).

Conclusion: Provisional crowns cemented with residual reactivated IRM possess adequate retentive values. Provisional crowns re-cemented with the other luting agents had lower mean retentive values and therefore re-cementation is not recommended.