Tensile bond strength between paediatric prefabricated zirconia crowns and primary maxillary incisors when using various types of luting cements: an in vitro study.

Purpose: There is limited evidence regarding the most appropriate type of luting cement for paediatric prefabricated zirconia crowns (PZCs) in primary maxillary incisors. The retention of PZCs is dependent on the bond strength of luting cement between PZCs and primary maxillary incisors. The aim of this study was to evaluate the tensile bond strengths between PZCs and primary maxillary incisors with different types of luting cements.

Methods: Thirty freshly extracted human primary maxillary incisors were prepared and randomly divided into three groups corresponding to three luting cements: bioactive cement, resin cement, and resin-modified glass ionomer cement (RMGIC), and then restored with PZCs. Tensile bond strengths were evaluated by a universal testing machine. The results were analysed using one-way ANOVA with Tukey's post-hoc test (p < 0.05).

Results: The means of the tensile bond strengths were 1.43 ± 0.85 MPa, 0.91 ± 0.63 MPa, and 0.56 ± 0.39 MPa for the bioactive cement, resin cement, and RMGIC groups, respectively. A significant difference in tensile bond strength was observed between the bioactive cement and the RMGIC group (p < 0.05) but there was no significant difference in tensile bond strength between the resin cement group and the others.

Conclusion: Types of luting cement influenced the tensile bond strength between PZCs and primary maxillary incisors. The bioactive cement showed higher tensile bond strength than the resin cement and RMGIC.