目前对种植体周围炎尚无十分有效的治疗方法，菌斑堆积是引发种植体周围炎的始动因素。现有的采用抗生素控制种植体周围炎的防控方法容易引起细菌耐药性且无法杀灭侵入细胞内的致病菌。作为能裂解细菌的病毒和酶，噬菌体及其裂解酶能快速杀死细菌，为预防和治疗种植体周围炎提供了新的机遇。因此本项目针对种植体周围炎的细菌感染，特别是胞内菌感染，筛选具有高效抗菌作用的嵌合裂解酶，并将其应用于种植体周围炎的抗菌治疗。本项目拟筛选针对种植体周围炎主要病原菌的高效嵌合裂解酶，与PTD融合，使之具备杀灭胞内菌的能力，在体外对其杀菌作用进行评价并探索其机制，同时构建种植体周围炎犬动物模型，结合羟乙基纤维素/大豆蛋白质复合海绵体内评价新型嵌合裂解酶对种植体周围炎的预防与治疗效果。

At present, it's lack of an effective way for the treatment of peri-implantitis, and plaque accumulation is the initiating factor of inflammation around the implants. The existing methods by antibiotics are easy to induce bacterial resistance and useless for the introcelluar bacterium. As virus or enzyme that can disintegrate bacterium, bacteriophage and its lyase can kill drug-resistant bacteria quickly. It provides a new opportunity to prevent and treat peri-implantitis. Thus, this project aim at the peri-implant bacterial infections, especially intracellular bacterial infection, screen for effective lyase of high antibacterial activity, then apply it to the prevention and treatment of peri-implantitis. This project intends to screen the highly effective chimeolysin targeting at main peri-implantitis bacterium, and PTD will be added to give chimeolysin the ability of killing the intracellular bacterium. The anti-bacterial effect and mechanism are evaluated in vitro. The canine peri-implantitis models are constructed, chimeolysin and Hydroxyethyl Cellulose/Soy Protein Isolate composite sponges are combined to clarify the preventive and therapeutic effect of chimeolysin on peri-implantitis at the same time.