Bond strength and microleakage of different types of cements in stainless steel crown of primary molar teeth

Background: The margin of crown is a significant area for plaque accumulations. Therefore, the ability of the cement to seal the margin is very important. The aim of the present study was to evaluate the bond (retentive) strength, microleakage, and failure mode of four different types of cements in stainless steel crown (SSC) of primary molar teeth. Materials and Methods: In this experimental study, eighty extracted primary molar teeth were divided into two groups of forty teeth to test the microleakage and bond strength. The crowns were cemented according to the manufacturer guidelines with four cement types including self‑cure glass ionomer, resin‑modified glass ionomer, polycarboxylate, and resin cements. Stereomicroscope and universal testing machine were used to measure the microleakage and bond strength, respectively. For calculating the surface area of crowns, three‑dimensional scanning was used. Furthermore, the failure mode was examined after the bond strength test. The cements surfaces and the tooth– cement interfaces were evaluated using scanning electron microscopy (SEM). The obtained values were analyzed using SPSS‑23 software through Shapiro–Wilk and one‑way analysis of variance tests. Means, standard deviations, medians, and interquartile ranges were calculated. P 0.05 was considered as statistically significant in all analyses. Results: Significant differences between microleakage (P = 0.001) and failure mode (P = 0.041) of the four types of cements were obtained. However, the mean bond strengths of the four groups did not differ significantly (P = 0.124). The obtained SEM images confirmed the results of bond strength and microleakage. Conclusion: Resin cement and resin‑modified glass ionomer, respectively, showed superior properties and are recommended for use in SSCs of primary molar teeth.