利用气体加压技术构建超级牙本质的基础研究

Compared to enamel, dentin has lower mineralization degree and looser structural composition. Imbedding with tubules is one distinct and important feature of dentin. These characters of dentin could be the crucial causes to the rapid development of caries and hypersensitivity in dentin. Severe tooth defect would be induced after the exposure of dentin and the durability of bonding to dentin is also weak until now. Therefore the modification to the components and structure of dentin is a efficient method to the clinical prevention and treatment of dentin hypersensitivity and caries as well as the improvement of bonding durability. Results in the previous research of our group indicated that there was a close relationship between adhesives penetration and air pressure in air-blowing process and the higher pressure could promote the infiltration. High-quality hybrid zone without nano-leakage could be observed by the first time. Therefore high-pressure air-blowing procedure might have s great significance to the dentin modification and improvement of the bonding stability. Aims of this project are as following: finding relationship between air pressure and adhesives infiltration and confirming technical parameters; researching the function of processing antibacterial adhesive, desensitizer and mineralization materials by using high pressure air-blowing procedure; exploring the strategy of acquiring modified dentin and establishing the "super dentin" by this technique. This project is expected to realize the purpose of the good prevention and treatment of hypersensitivity and caries of dentin and increase the probability of clinical success to adhesive restoration.

与牙釉质相比牙本质的矿化度低、结构疏松并存在大量管状结构，因此由于各种原因所致的牙本质暴露是造成龋齿、牙齿敏感，甚至牙体缺损的重要因素，也是牙本质-树脂粘接修复临床耐久性不理想的原因。因此对牙本质的结构和成分改性是治疗牙本质敏感、预防或修复牙本质龋及提高牙本质-树脂粘接修复耐久性的重要策略，具有十分重要的临床价值。本课题组前期研究发现：粘接剂在牙本质中的渗透与吹拂气体压力直接相关，增大气压可将材料导入牙本质更深部，并首次观察到这种方法可形成无纳米渗漏的混合层，这对牙本质改性和提高粘接界面稳定性具有重要意义。本项目的目的是：进一步明确气体压力与粘接剂渗透的关系，确定最佳处理参数；研究高压气体促进抗菌粘接剂、牙本质脱敏及再矿化材料在牙本质中的渗透效果；探索通过此技术对牙本质结构和成分进行改性，构建"超级牙本质"的可行策略，实现防治牙本质敏感、抑制牙本质龋及提高树脂粘接修复体耐久性的目标。

与牙釉质相比，牙本质的矿化程度低，含有胶原纤维并存在大量牙本质小管结构，因此由于各种原因所导致的牙本质暴露是造成牙齿敏感、牙体缺损进一步加重的重要因素，同时这也是牙本质树脂粘接修复效果不佳的根本原因。课题组前期研究发现，如果能够促进粘接树脂在牙本质中的渗透，以此获得高质量的牙本质-树脂混合层，则有可能起到改善粘接修复效果，提高牙本质表面性能的作用。本项目针对此问题，利用气体加压技术，增加涂布粘接剂时吹拂气体的压力，以此对抗牙髓牙本质复合体产生的阻碍粘接剂渗透的不利因素。本项目通过多次试验，确定了气体加压技术促进牙本质粘接效果的最佳技术参数，并且建立了多种牙体组织及修复体粘接模型，全面评估了气体加压技术在全酸蚀粘接系统、自酸蚀粘接系统、纤维桩树脂水门汀粘接、瓷粘接偶联剂中的应用效果。在确定该气体加压技术能够提高粘接强度，改善粘接耐久性的同时，深入探讨其可能的作用机制，并在此基础上发现气体加压技术构建的牙本质粘接剂混合层能够加强牙本质表面性能，抵抗口腔中致龋因子的侵袭破坏，起到预防继发龋发生发展的作用。进一步提出了负压粘接技术，利用真空去除牙本质中剩余的空气水分，促进粘接剂渗透，提高粘接强度。本项目经过系统的研究，证明了气体加压技术这种简单而有效的方法，可通过构建一层高质量的牙本质-树脂混合层，起到加强牙本质性能，改善粘接修复效果的作用，具有重要的临床意义。并可进一步形成新的口腔治疗设备，具有良好的应用前景。