Self-driven micromotors loaded with photosensitive adhesives and their application in dentin sensitivity

Dentin hypersensitivity is primarily caused by the exposure of dentinal tubules due to various factors, so the key to treatment is to effectively seal these exposed tubules. However, traditional dentinal tubule sealants used in clinical practice often fail to adhere securely to the tubule surface when exposed to external stimuli, resulting in a recurrence of sensitivity. In this study, we developed a silicon micromotor that moved autonomously and loaded with silver nanoparticles and a photosensitive adhesive for dentin sensitivity therapy. These micromotors move autonomously to reach deep into the dentin tubules and surface loaded adhesives are solidified under blue light. The compact structure formed by the cross-linking of micromotors effectively seals the dentin tubules from the inside to the outside, and also forms a firm bond between the micromotor and the inner layer of the dentin, thereby improving the sealing effect and providing strong protection. Silver nanoparticles on the surface of micromotors can slowly release silver ions, effectively inhibiting the growth of caries-causing bacteria such as S. mutans, and preventing secondary caries. Our research demonstrates that the closure rate of dentinal tubules after treatment can reach 79.17% with a closure depth of 17.22 μm, while also withstanding various stimuli without detachment. In conclusion, the use of self-propelled micromotors presents a promising new strategy for treating dentin hypersensitivity in clinical settings.