Unit 23. Endodontic microbiology and infection-related processes.pdf

Microbiology Unit 23 Endodontic microbiology and infection-related processes Ve más allá 1 •Endodontics: branch of dentistry concerned with the diagnosis and treatment of injuries and diseases affecting the tooth root, the pulp and periapical tissues. Dental Pulp: Connective tissue highly vascul...

Microbiology Unit 23 Endodontic microbiology and infection-related processes Ve más allá 1 •Endodontics: branch of dentistry concerned with the diagnosis and treatment of injuries and diseases affecting the tooth root, the pulp and periapical tissues. Dental Pulp: Connective tissue highly vascularized and innervated, which is located in the central cavity of the teeth. It is surrounded by dentin and has nutritional, sensory and protective functions. PATHOGENESIS INFECTION OF THE ENDODONTIC Dental Pulp: Connective tissue located inside a chamber of dentin and relates to the periapical area through the apical foramen • pulpitis: inflammation of the pulp • apical periodontitis: inflammation of periradicular tissues The evolution of pulp and periradicular infections is variable: • acute • chronic PATHOGENESIS INFECTION OF THE ENDODONTIC The oral microorganisms are the most common cause of pulp infection. Endodontic infection depends on: • properties of the infecting organism • the conditions of the pulp tissues • host defense PATHOGENESIS INFECTION OF THE ENDODONTIC The pulp is protected from microorganisms by: • Enamel, cementum and dentin Causes that can alter physical barriers: • Endogenous factors: systemic diseases such as diabetes, hypophosphatasia and others • Exogenous factors: the most prevalent  Physical  Chemical  Microbial (oral microbiota) PATHOGENESIS INFECTION OF THE ENDODONTIC Invasion pathways (routes) used by the microbiota 1. Direct communication of the oral cavity with the pulp May be due to: • Carious lesion • Dental fractures • Cracks or fissures of enamel • Traumatic exposure during dental treatment 2. Dentinal tubules The most prevalent cause of infection of the dental pulp is communication of carious dentin through the dentinal tubules PATHOGENESIS INFECTION OF THE ENDODONTIC Invasion pathways (routes) used by the microbiota 3. Periodontal entry In patients with periodontitis 4. Marginal leakage of restorations Through the interface between the restorative material and the tooth 5. Contiguity Infectious processes adjacent to the tooth structure 6. Anachoresis Through the bloodstream (hematogenous) PATHOGENESIS INFECTION OF THE ENDODONTIC Microbial aggression 1. Factors affecting colonization Entry and infectious dose Local adhesion and proliferation 2. Virulence factors Exotoxins, endotoxins, bacterial enzymes and metabolites Host response Inflammatory response: • Acute phase: neutrophils and macrophages • Chronic phase: lymphocytes, macrophages and plasma cells: formation of granulomas (encapsulated by connective tissue injury and those cells) Cells of inflammation release mediators (cytokines) that: • Attract other inflammatory cells • Produce hyperemia (increased vascularity) • Stimulate nerve endings and cause hyperalgesia (pain) • Stimulate osteoclasts to increase bone resorption • Degrade the extracellular matrix Periapical injuries Acute apical periodontitis Chronic apical periodontitis Periapical abscesses Bacteriology of infectious endodontic processes 1. Microbiota associated with endodontic pathology of vital teeth The entry used by microbiota to infect the pulp determines the microbial composition of the infection 2. Microbiota associated with endodontic condition of teeth with pulp necrosis • Same routes of entry in vital or necrotic pulp • Porphyromonas and Prevotella are predominants (strict anaerobes) Major bacterial infections related to the vital pulp Entry routes Microbiota Caries or trauma Any oral bacteria Prevalence of streptococci of viridans group and Lactobacillus spp. Dentinal tubules Cariogenic bacteria Prevalence of streptococci of viridans group, Lactobacillus spp. Actinomyces naeslundii Periodontal route Gram + bacteria Peptostreptococcus spp., Streptococcus spp. Propionibacterium spp., Rothia dentocariosa Contiguity Bacteria responsable of primary infection Anachoresis Bacteria from the septicemic foci Clinical features (symptoms) 1. Hyperalgesia (= pain), the first response to microbial attack, is an alarm mechanism 2. Symptomatic pulpitis: pain does not go away after the withdrawal of the stimulus that caused it.  Acute: intermittent pain.  Chronic: moderate pain, diffuse and difficult to locate 3. Asymptomatic pulpitis: inflammatory response of the pulp tissue but the pain is not perceived at the affected tooth HIGH microbial aggression LOW microbial aggression High amount of bacteria or high virulence Low amount of bacteria or low virulence Short time Long time Symptomatic pulpitis (vital pulp) Asymptomatic pulpitis (necrotic pulp) • Root canal treatment • Host response Hyperalgesia (vital pulp) Host response ineffective effective effective ineffective Apical periodontitis Healing Microbiological diagnosis in Endodontics Methods 1. Direct examination: fast but not very useful 2. Culture • Sample collection method: difficult without contamination: (sterile paper in the root canal) • Sample processing: you need expert professional It is only done in 2 cases: • Patients with endodontic conventional treatments infections resistant to • Immunosuppressed patients, to identify and treat primary foci of infection Treatment Mechanical treatment of root canals Antibiotic treatment: • Purulent symptomatic irreversible pulpitis • Pulp necrosis • Immunocompromised patients Choice: amoxicillin + clavulanic acid Alternative: clindamycin or metronidazole + spiramycin THANKS FOR YOUR KIND ATTENTION! QUESTIONS PLEASE? Ve más allá © Copyright Universidad Europea. Todos los derechos reservados