Background & Aim: The use of intra-orifice barriers helps reduce coronal leakage, enhances sealing in the intra-orifice area, and improves the success rate of root canal therapy. This study aimed to investigate the effect of contact time on the push-out bond strength of intra-orifice barrier materials in temporary restorations.                                                                    

Material & Method: This in vitro study used 110 single-rooted teeth, with crowns sectioned 2 mm below the CEJ. After preparing access cavities, the samples were divided into two experimental groups (A: Quizol and B: Zonalin) and two control groups (C: positive control and D: negative control). Groups A and B were further divided into subgroups based on the duration of temporary restoration (2 weeks and 4 weeks) and the type of barrier material (composite flow and RMGI). Dentinal blocks were prepared, and samples were subjected to a push-out bond strength test. The data were analyzed using a generalized linear model and Kruskal-Wallis test, with significance set at p<0.05. 

Results: General comparison revealed a statistically significant difference among the experimental groups (P = 0.000). Pairwise analysis showed that the Cavit-4 weeks-composite flow subgroup exhibited the highest push-out bond strength (6.70 ± 1.76), significantly greater than all other combinations (P = 0.000). In contrast, the positive control group (cotton with eugenol-2 weeks-composite flow) showed the lowest bond strength (0.302 ± 0.101).

Conclusion: Cavit temporary restoration significantly enhanced the bond strength of composite flow barriers after 4 weeks, outperforming other materials and time combinations.