Genome and Cell Structure - The first genome of T. denticola was sequenced from strain 35405. - The genome sequence encodes 2,786 open reading frames (ORFs), 6 rRNAs, and 44 tRNAs. - T. denticola has a larger genome compared to Treponema pallidum, which only encodes 1,040 ORFs. - Genome sequencing provides important information about the genetic makeup and potential functions of T. denticola. - Understanding the genome helps in studying the pathogenicity and survival mechanisms of T. denticola. - Cryo-electron tomography revealed the native cellular architecture of T. denticola. - T. denticola has tightly organised bundles of periplasmic flagella, allowing it to rotate, flex, and move translationally. - The tapering of the cell ends and the patella-shaped structure at the cell tip are involved in polar attachment. - Cytoplasmic filaments composed of the protein CfpA are critical for pathogenicity and various cellular processes. - Deficient mutants lacking flagella or cytoplasmic filaments show increased uptake by mouse peritoneal macrophages.

Adherence and Cytotoxicity - T. denticola attaches to proteins of local gingival fibroblasts in the gingival crevice. - A 53-kDa surface protein on T. denticola transports its components into the host cell and exhibits cytotoxic effects. - Accumulation of T. denticola facilitates disease-causing processes like membrane blebbing and red blood cell lysis. - The binding of T. denticola to fibroblasts and epithelial cells contributes to the release of bacterial contents. - The bacterial components of T. denticola include peptidases, proteinases, hemolytic and hemagglutinating activities, and pore-forming proteins.

Role in Disease - Periodontal Disease - T. denticola is associated with periodontal disease, which is caused by the accumulation of plaque and poor oral hygiene. - It is found in periodontal pockets along with other gram-negative bacteria, contributing to the development of periodontal disease. - T. denticola damages the surface lining of periodontal cells and increases their susceptibility to damage and lysis. - The presence of T. denticola is particularly observed in patients with orthodontic appliances. - T. denticola is implicated in various periodontal disease conditions, including the early stage of periodontitis and necrotising ulcerative gingivitis.

Role in Disease - Oral Cancer - T. denticola is a potential etiological bacterial agent for oral cancer. - It promotes oncogenesis and the progression of oral cancer through chronic inflammation and inhibition of controlled cell death. - T. denticola suppresses the immune system and produces cancer-promoting substances. - The presence of T. denticola, along with other periodontal pathogens, contributes to the development of cancerous cells. - T. denticola is associated with precancerous gastric lesions and may play a role in intestinal cancer.

Clinical Implications and Management - Treponema denticola is an important consideration in periodontal care. - Changes in oral microbiota due to orthodontic appliances have been studied. - The role of T. denticola in periodontal diseases has been extensively reviewed. - The bacterium has implications in the management of acute dental problems. - Understanding the pathogenicity of T. denticola is crucial for dental healthcare professionals.