Photodynamic Therapy for Endodontic Disinfection

根管治疗失败是由于残留在根管中的细菌大量繁殖所致。 由于根管系统的复杂性，需要使用器械进行彻底清创 仅靠灌溉几乎是不可能的。我们的长期目标是开发光动力疗法(PDT)作为一种 根管预备加钠灌洗后残留根管细菌的辅助清除技术 次氯酸盐(NaOCI)。这项研究要检验的具体假设是，可见光可以实现 光敏剂对根管残留微生物敏化后的快速彻底杀灭 毒品。具体目标是： 1.利用牙髓失败中常见的微生物开发单物种和多物种生物膜 和/或拔除的牙齿的表面以及根管系统的牙本质小管上的感染。 我们将(I)通过扫描电子显微镜和共聚焦扫描激光来表征这些生物膜 显微镜下，我们将(Ii)使用棋盘DNA-DNA杂交、聚合酶链式反应来分析它们 聚合酶链式反应(PCR)检测和培养。 2.研究光对根管生物膜的体外破坏作用。我们将(I)建立光的参数 和光敏剂用于完全消除根管微生物生物膜，(Ii)评估细菌 以及(3)评估细胞杀灭在生物膜内的分布。 3.评价光动力疗法的安全性。我们将(I)测定人牙周组织的活性 治疗后的韧带和骨细胞，(Ii)确定治疗窗口，通过该窗口微生物可以 在不影响宿主细胞活力的情况下被灭活，以及iii)研究诱导细胞凋亡。 4.评价光动力疗法对人牙体外抑菌效果。我们将使用新鲜的 取患牙评价光动力疗法对牙周组织残留细菌的影响 完成根管预备和NaOCI冲洗后的根管系统。 与公共健康相关：超过200万例因残留微生物而重新治疗的根管 在美国每年演出一次。光动力疗法可能是杀死残留根管的一种辅助方法 细菌在被一种具有光活性的药物敏化后，随后暴露在光中。

Endodontic failures are caused by the proliferation of residual bacteria that are left behind within the root canal due to the complexity of the root canal system that makes complete debridement with instrumentation and irrigation alone almost impossible. Our long-term goal is to develop photodynamic therapy (PDT) as an adjunctive technique to eliminate residual root canal bacteria after instrumentation and irrigation with sodium hypochlorite (NaOCI). The specific hypothesis to be tested by this research is that visible light can achieve a rapid and complete killing of residual root canal microorganisms after their sensitization with a photoactive drug. The specific aims are to: 1. Develop mono- and multi-species biofilms with microorganisms that are common in endodontic failures and/or infections on the surface as well as in the dentinal tubules of root canal systems of extracted teeth. We will (i) characterize these biofilms by scanning electron microscopy and confocal scanning laser microscopy and we will (ii)analyze them using checkerboard DNA-DNA hybridization, polymerase chain reaction (PCR) assays and culture. 2. Investigate the photodestruction of root canal biofilms in vitro. We will (i) establish the parameters of light and photosensitizers for the complete elimination of root canal microbial biofilms, (ii)evaluate bacterial killing, and (iii)assess the distribution of cell killing within the biofilms. 3. Assess the safety of photodynamic therapy. We will (i) determine the viability of human periodontal ligament and bone cells after treatment, (ii)determine the therapeutic window whereby microorganisms can be inactivated without affecting host cell viability, and iii) investigate the induction of apoptosis. 4. Evaluate the antimicrobial effects of photodynamic therapy in human teeth ex vivo. We will use freshly extracted infected human teeth to evaluate the effect of photodynamic therapy on residual bacteria in the root canal system after complete instrumentation and irrigation with NaOCI. Relevance to public health: More than 2 million root canal retreatments due to residual microorganisms are performed yearly in the US. Photodynamic therapy may be an adjunctive procedure to kill residual root canal bacteria after their sensitization with a photoactive drug and their subsequent exposure to light.