Aims and objectives of root canal therapy Flashcards
What is root canal therapy?
The complete removal of the irreversibly damaged pulp from the entire root canal root canal system
First line of defence
Pulpal tissue
How do bacteria gain access to the pulp space?
Caries Cavity prep Micro-leakage around restorations Cracks Trauma Desiccation Periodontal disease
Aim of RCT
To prevent or treat periapical periodontitis by controlling infection
The complete removal of the irreversibly damaged pulp from the entire root canal root canal system
Objectives of RCT
Complete removal of irreversibly damaged or necrosed dental pulp from entire RC system (mechanical prep)
Dissolution and debridement of inflamed and infected tissue from pulp space by thorough cleansing, disinfection and shaping (chemical prep)
Create an optimal shape to allow well-compacted RC filling to be placed into RC system (obturation)
Process of pulpal necrosis
> 800 species of microbe inhabit mouth
Microbial products react with pulp causing inflammation
Development of microbial ecosystem within RC system
Pulp necrosis and development of periapical lesion
Pulp functions
Formative: dentinogenesis
Sensitivity: sensory innervation, pain
Nutrition: vascularization (O2 and nutrients)
Defence: against microbial infection by sclerotic or tertiary dentine
Development of periapical lesion
Cementum prevents release of bacterial toxins from RC spacee along dentinal tubules and out into PDL, toxins released through apical foramen and lateral canals
Types of caries
Advanced (rapdily progressing)
Superficial (slowly progressing)
Inactive (arrested)
Outcome worse if periapical lesion or not
Have to pay attention to caries, with periapical infection worse prognosis
Second line of defence
Peri-apex
Tissue fluids, inflammatory exudate, immune cells
Pre-operative assessment (clinical and radiographic)
Restorability of tooth
Visibility of pulp chamber and canal space
Shape of canal (straight, curvature)
Number of roots and canals
Presence of any PA lesion (size, location)
Presence of any previous root-treatment
Restorability of the tooth
Remaining tooth structure Existing restorations Extra-coronal restoration Crack Periodontal support
Visibility of pulp chamber and canal space
Patent
Sclerosed
Pulp stone
Dentine-pulp complex protective mechanisms against caries
< dentine permeability (dentine sclerosis)
Tertiary dentine formation
-reactionary dentine (superficial caries, mild stimulus, primary odontoblasts)
-reparative dentine (advanced caries, severe stimulus, odontoblast-like cells)
