Abstract Background Clinicians often utilize both flowable and packable composites concurrently in bonding fixed retainers. Thus. this study aimed to assess the synergistic effect of these composites in the bonding process. Methods This in vitro study divided specimens into three groups: flowable composite (nano-hybrid. https://www.chiggate.com/color-charm-12n-1200-high-lift-blonde-1-4oz-online-now/