Fracture Resistance of Prefabricated Primary Zirconium Crowns Cemented with Different Luting Cements

Purpose: The purpose of this study was to determine the retention of prefabricated primary zirconium crowns (PPZCs) and the fracture resistance of samples cemented with four different luting cements subjected to a chewing simulation test with thermocycling mechanical loading (CSTTML). Methods: A total of 120 extracted primary molar teeth were selected and allocated into four groups, according to luting cement materials (bioactive cement, resin cement, glass ionomer cements [GICs], resin-modified GICs). After half of each group was subjected to CSTTML, all the samples were subjected to fracture tests and the mean force required to fracture the PPZCs was recorded. Results: After the CSTTML test, corresponding to a simulated one-year aging, none of the sample materials were found to be cracked, fractured, chipped, or non-retained. Resin cements in all groups showed the highest fracture resistance, whereas bioactive cement, subjected to CSTTML and resin-modified GIC in all tests, showed the lowest values. However, no statistically significant differences were found. Conclusions: The prefabricated primary zirconium crowns were found to be successful after almost one year of simulated aging. The results of all of groups showed that the PPZCs cemented with resin and glass ionomer cements were more successful. However, further in vitro and in vivo studies are needed to determine their potential for clinical success.