Immediate and Long-Term Pull-Out Bond Strength of 3D-Printed Provisional Crowns

Background: Over the past decade, 3D printing technology has revolutionized various fields, including dentistry. Provisional restorations play a crucial role in prosthetic rehabilitation, necessitating the evaluation of their bond strength with different provisional cement agents. Aims: This study is aimed at assessing the immediate and long-term bond strength of 3D-printed dental crowns using three provisional cement agents. Materials and Methods: Provisional crowns (N = 36) were manufactured using 3D modeling software and cemented in dentin analogues (G10 Nema resin). After the crowns' fabrication, they were randomly divided into three groups (n = 12) for cementation with Relyx Temp 3M ESPE, Provicol-VOCO, and Meron-VOCO. Tensile strength tests were conducted using a universal testing machine, with half of the specimens subjected to 2000 thermal cycles before testing. Finite element analysis was employed to assess tensile stress distribution. Results: Statistical analysis (two-way ANOVA and Tukey's test at a 95% confidence level) revealed significant effects of cement type (p = 0.006) and thermal aging (p = 0.001) on bond strength. Glass ionomer cement exhibited the highest immediate resistance, while all types of cement were adversely affected by thermal aging, resulting in decreased bond strength. Conclusion: Thermal aging significantly alters the properties of 3D printing resin and affects the bond strength of provisional cement with 3D-printed crowns. Despite the adverse effects of thermal aging, glass ionomer cement demonstrated the highest immediate resistance. Clinicians should carefully consider these findings when selecting provisional cements for 3D-printed crowns.