Detection of nano-controlled molecular interaction of functional monomers at adhesive interfaces for hard tissue reconstruction

虽然使用粘结剂技术可以微创、几乎不可见地重建龋坏/折断的牙齿，但牙科复合修复体的临床寿命仍然太短。水分吸收被认为是生物材料-牙齿结合不稳定的主要原因。然而，界面降解的实际机理还远未被了解。在这里，我们报告了生物材料-硬组织界面上的纳米控制分子相互作用如何提高粘结耐久性。使用对羟基磷灰石中的钙具有很强化学亲和力的功能单体对于长期耐用性是必不可少的。相关的X-射线衍射和固态核磁共振揭示了界面上与羟基磷灰石形成稳定的离子键的界面上与时间相关的分子相互作用，与较不稳定的磷酸钙盐的沉积在时间上竞争。先进的牙齿-生物材料相互作用模型不仅揭示了粘结降解的机理，而且为开发更耐用的牙齿重建功能单体提供了基础。

Although decayed/fractured teeth can be reconstructed minimally invasively and nearly invisibly using adhesive technology, the clinical longevity of dental composite restorations is still too short. Water sorption is thought to be the principal cause of destabilization of the biomaterial-tooth bond. However, the actual mechanisms of interfacial degradation are far from understood. Here we report how nano-controlled molecular interaction at the biomaterial-hard tissue interface can improve bond durability. The use of functional monomers with a strong chemical affinity for the calcium in hydroxyapatite is essential for long-term durability. Correlative X-ray diffraction and solid-state nuclear magnetic resonance disclosed a time-dependent molecular interaction at the interface with stable ionic bond formation of the monomer to hydroxyapatite competing in time with the deposition of less stable calcium phosphate salts. The advanced tooth-biomaterial interaction model gives not only an insight into the mechanisms of bond degradation, but also provides a basis to develop functional monomers for more durable tooth reconstruction.