Comparison of the marginal microleakage of a bioactive composite resin and traditional dental restorative materials

The primary objective of this study was to evaluate the marginal microleakage of Activa Kids BioActive-Restorative used with an adhesive bonding agent (AB+) and compare it with the microleakage of a traditional composite resin (CR), a resin-modified glass ionomer cement (RMGIC), and Activa Kids BioActive-Restorative placed without the use of an adhesive bonding agent (AB-). Standard Class I cavities were prepared in 200 extracted, caries-free permanent molars, which were then restored with 1 of the 4 restorative materials (n = 50 each). The restored teeth were thermocycled for 500 cycles, alternating between 5°C and 55°C with a dwell time of 25 seconds; stained with basic fuchsin dye with a soak time of 24 hours; and sectioned buccolingually. Microleakage was assessed independently by 2 evaluators who viewed specimens under a dissecting microscope at ×30 magnification and assigned scores according to a standardized microleakage scale. Because a Spearman correlation test showed a high correlation between the scores assigned by the 2 evaluators, their ratings for each of the 4 test groups were pooled, and a modified Wilcoxon rank sum test (P < 0.05) was used to analyze the microleakage scores. No difference in microleakage was observed between the AB+ and CR groups (P = 0.8652). Statistically significant differences in microleakage were observed between the AB+ and RMGIC groups (P < 0.0001) as well as between the AB+ and AB- groups (P = 0.0324). The results showed that AB+ had a mean microleakage rate comparable to that of traditional CR. Moreover, AB+ exhibited a lower mean microleakage rate than RMGIC; both the bioactive composite resin and RMGIC are fluoride-releasing materials, so clinicians should consider using AB+, especially in high-caries-risk patients, who are vulnerable to recurrent caries resulting from microleakage and benefit from fluoride release. In this study, AB+ exhibited a significantly lower mean microleakage rate than AB-; therefore, this bioactive material should be used with a bonding agent.