Endodontology Flashcards
What is it?
Understanding the form, function, health of, injuries to and sciences of disease of the pulp. The prevention and treatment of diseases to the pulp and periradicular region.
What is pulp dentine?
Specialised tissue showing primative response to stimuli - recognises pain or not.
What are the functions of the pulp?
Development of the tooth (endomesenchyme)
Sensation (pain)
Nutrition (blood supply)
Defence (partially effective)
What is the response to irritation?
Inflammation (increased blood flow in enclosed space = pain) Secondary dentine Arterio-venous shunts Recovery Death
What are causes of injury to the pulp?
Caries Dentistry (iatrogenic damage) Scaling Trauma Loss of tooth substance through tooth wear Periodontal diseases
What are the bacterial species’ involved in the root canal system?
Mixed aerobes and anaerobes
Killed by proteolytic substances which attack proteins
What are periradicular tissues and their response to infection?
Surrounding alveolar bone, cementum and periodontal ligament, protective response to infection.
Why may LA not work?
Hyperaemic pulp - acute pulpal inflammation/hyperexcitability of nerve fibres (C fibres) means LA is unable to block the conduction of these impulses.
Increased vascularity may remove LA more rapidly and pH of products may be more acidic
Infection
Patient factors - anxiety
What are additional anaesthesia techniques?
Intraligamentary
Intrapulpal
Intraosseous
Why is rubber dam mandatory?
Protection of airway Protection of irrigants Prevention of contamination Improved access and visualisation Patient comfort
What is used to seal a rubber dam and secure it?
Rubber wedgit and oraseal around the tooth once rubber dam placed.
What must be ensured regarding condition of tooth before treatment?
Crown restorable
Caries and defective restorations removed
Sound coronal restoration
Why do we take periapical radiographs?
- Number of canals
- Number of roots
- Morphology of canals
- Extent of current restoration
- Presence of caries
- Presence of canal sclerosis/pulp stones/previous RCT/fractured instruments
What is the aim of access?
Remove roof of pulpal chamber No damage to pulpal floor Straight line access Conservative Retentive for temporary restoration
What do you need to find canals?
Good light, loupes, magnification, explorer
How can safe ended burs be used around the floor of the pulp chamber?
They have no cutting flutes or diamond at the tip so can be used safely around floor.
What can ultrasonic instruments do?
Carefully remove infected dentine around canal orifices and prep the canals.
What is chemomechanical preparation?
Mechanical cleaning and shaping with files and chemical disinfection.
Which part is prepared first?
Coronal part, removes heavily infected tissue and prevents bacteria being carried apically.
Straight part prepared with - gates glidden burs and files and the remainder 2/3 with files, irrigation used throughout.
What do gates glidden burs do?
Don't cut at the tip Will stay within the canal Steel Break easily Designed to break at shank Sized according to number of bands
What do we use in the apical 1/3
K - files
Stainless steel
Sized according to diameter at tip
10 = 0.1mm
What are qualities of a intra-canal medicament?
Antibacterial, aids periapical healing, therapeutic, anti-inflammatory, long lasting, non-irritant, easy to remove and cheap.
When do we use intra canal medicaments?
Persistent infection, unable to dry prepared canal, incomplete apex, incomplete prep, insufficient time for obturation.
What properties of CaOH mean it is an intracanal medicament?
Antibacterial Aids repair Apexification Dissolves debris Easy to remove
What is the aim of temporisation?
Seal tooth, restore function, prevent over eruption, restore aesthetics
What is the aim of obturation?
3D seal of canal preventing microorganisms entering and reinfecting. Use GP cones and finger spreaders to condense.
Different types of sealers
Zinc oxide eugenol - fills in voids
CaOH - antibacterial
Glass ionomer - radiopaque
How does disease start in the pulp-dentine complex?
Ongoing carious insult Trauma Periodontal problems TSL Dental procedures
Caries - pulpal disease - periapical disease - extends into dentine - pulp inflammation and laydown of tertiary dentine.
Fluid movement in dentinal tubules causes pain
Pulp starts to calcify and move away, removing caries will maintain vitality if not inflammation becomes irreversible.
What is pulpal necrosis?
No blood supply in the root canals, last nerve cells to die are the c fibres - severe pain of irreversible pulpitis.
What is a biofilm?
Aggregation of micro-organisms growing on solid substrate, complex community interactions, extracellular matrix of polymeric substances.
What bacteria are in the apical region?
Low oxygen, facultative anaerobes, lower bacterial counts but less accessible to treatment
What bacteria are in the coronal region?
High oxygen, more carbohydrate and nutrients, higher counts and more accessible to treatment
What is periapical disease?
Biofilm forms within root canal and matures
Disease is inflammatory immune system reacting to presence of microbes and their products apically.
What are the zones of fish?
Infected
Contaminated
Irritated
Stimulated
What is an apical granuloma?
Consists of granulomatous tissue with inflitrate cells, fibroblasts and well developed fibrous capsule, no live bacterial content.
Epithelium may grow into entrance of root canal forming plug like seal at apical foramen.