1 - Introduction to Endodontics Flashcards
what is endodontology?
a branch of dental science concerned with the study of:
form, function, health of, injuries to and diseases of the dental pulp and peri-radicular tissues
what is endodontics?
the clinical discipline that deals with the prevention, diagnosis and treatment of endodontic disease
what is considered endodontic treatment? examples?
any procedure designed to maintain the health of the pulp
e.g. stepwise, indirect pulp cap, direct pulp cap
how does endodontic treatment aim to solve:
- injured/diseased pulps?
- disease of periradicular tissues?
- by maintaining or restoring health of the periradicular tissues
- by restoring them to normality
root canal treatment is required for teeth when?
- when the dental pulp is irreversibly damaged
- elective root canal treatment: required to allow placement of post-retained crowns
list the general methods of how microbes enter teeth? x6
- caries
- dental factors
- physical trauma
- tooth surface loss
- micro-leakage
- periodontal disease and treatment
how microbes enter teeth - caries: how does it occur? pulp becomes inflamed when?
- occurs when bacteria penetrate the tubules and cause destruction of dentine
- pulp becomes inflamed when bacteria is 0.5mm away
how microbes enter teeth - dental factors: what are the examples?
- crown/bridge preparation
- accidental pulpal exposure
- inadequate water spray
- over-drying exposed dentine
- inadequate isolation of teeth from saliva
- failure to adequately protect and seal tubules
how microbes enter teeth: examples of physical trauma?
infractions
crown/root fracture
how microbes enter teeth: examples of tooth surface loss?
- attrition
- abrasion
- erosion
- abfraction
how microbes enter teeth: microleakage - why does it occur?
due to poor adaptation of materials, allowing bacteria to enter
how microbes enter teeth: how does it occur in peridontal disease and treatment?
- through the patent lateral accessory canals
- surgical procedures
dentine hypersensitivity: characterized by? stimuli? mechanism of sensitivity? causes? treatment?
- exaggerated, sharp, transient pain
- thermal, chemical, osmotic, tactile or physical stimuli.
- fluid movement in the tubules activate A-delta fibres
- caused by gingival recession and tooth surface loss
- occlude or cover patent tubules
cracked tooth syndrome:
- described as?
- difficulty with?
- what happens if untreated or unrecognized?
- incomplete fracture of a posterior tooth with a vital pulp, fracture may include dentine and pulp
- difficult to diagnose
- may lead to vertical root fracture and extraction of tooth
cracked tooth syndrome:
aetiology?
symptoms?
- occlusal forces, abnormal chewing habits, accidental trauma, structural fatigue
- sharp shooting pain on biting hard objects
- may be worse on release of pressure
- sensitivity to thermal changes, sweet, acidic food
- often difficult to diagnose
hyperplastic pulpitis:
- characterized by?
- appears as what in young patients?
- symptoms?
- radiographic changes?
- proliferatin of pulpal tissue to produce a pulp polyp
- large carious lesion
- symptomless
- not normally any radiographic changes
indications for root treatment?
age
- no limit
- canals narrow in older people, healing process slower
patient’s state of health
- endodontics often easier and safer than extraction
- bisphosphonates: risk of osteonecrosis
reasons to carry out RCT?
- removes aetiological factors to allow healing
- prevent reinfection of the root canal system by placing an effective coronal seal
- allows the tooth to become a healthy functioning unit
general contraindications to RCT?
- medical history: usually little to contraindicate, patients with diabetes type I and II may have a slower healing and reduced success rate
local contraindications to RCT?
- difficult access to posterior teeth
- patient MUST lie back
- tooth must be isolated using rubber dam
- patient must tolerate rubber dam
specific contraindications to RCT?
- insufficient periodontal support
- inadequate root/crown ratio
- insufficient coronal tooth structure
- root caries/furcation
- internal resorption with perforation
- vertical root fracture
false contraindications?
- fractured instruments
- calcified pulp chambers, canals
- anatomical complexities
- difficult retreatments
- size of periradicular lesion
systemic disease and endodontics:
- those at risk of infective endocarditis?
- those with prosthetic joints?
- steroids?
- anticoagulants?
- those at risk no longer require antibiotic prophylaxis
- those with prosthetic joints at no special risk
- patients on long term steroid medication do not require supplementary steroid cover for routine dentistry under LA
- those on anticoagulants only require stable INR range of 2-4, those on warfarin should have INR checked 72hours before surgery
patients on warfarin - what should NOT be prescribed to them following endodontic surgery?
- NSAIAs
- cox-2 inhibitors
pregnancy and endodontic treatment:
- avoid treatment when?
- treat what first?
- radiographs only when?
- avoid treatment in first trimester, relief pain first and continue treatment in second or third trimester
- use radiographs only when necessary
antibiotics in pregnancy: what to use? what to avoid?
use:
- penicillin V
- amoxicillin
- clindamycin
- metronidazole
avoid:
doxycycline
tetracycline
vancomycin
pregnancy and endo treatment: supine hypotension syndrome caused by compression of which vessel? why is the vessel compressed? compression can result in? how to manage during dental treatment?
- inferior vena cava
- IFC compressed by the uterus
- reduced perfusion of uterus, fetal hypoxia
- roll onto left side, or place small pillow under right hip
aetiology of pulpal and periradicular disease? which studies can back this up?
- bacteria
1. surgical exposure of dental pulps in germ-free and conventional lab rats
2. influence on periapical tissues of indigenious oral bacteria and necrotic pulp tissue in monkeys
root canal microorganisms: polymicrobial infection - how many species per canal?
what types of microorganisms?
- 20 species per canal
- facultative anaerobes decrease
- obligate anaerobes
- more gram negatives
- fungi + viruses
microbial distribution:
most located where?
what forms on canal walls?
- mostly located in suspension within the root canal
- bioflims form on canal walls
- dentinal tubules occluded?
microbial distribution: list the various species found? x9
prevotella porphyromonas fusobacterium veillonella peptostreptococcus eubacterium actinomyces lactobacillus streptococcus
pulp chamber:
located where?
dimensions vary according to?
projects into what in well developed cusps?
- portion within crown
- dimensions vary according to
1. outline of crown
2. structure of root - projects into pulp horns
pulp root canal: continuous with? how does shape change at apex? constriction at the end known as? emerges where?
- continuous with pulp chamber
- tapers towards the apex
- apical constriction
- apical foramina
anatomy of the root canal system:
- describe it and how the canals are
- how does the diameter change
- where is the narrowest point?
- often complex
- canals may divide and then rejoin, they tend to be broader buccolingually than mesiodistally
- diameter decreases towards the apical foramen
- 1-1.5mm from the apical foramen
root canal classification: known as? how many are there?
vertucci canal types
- there are 8 types
pulp and periodontal tissue can also connect through?
accessory and lateral canals
lateral canals:
found where?
where in molar teeth?
- found anywhere along the length of the root canal, at right angles to the main canal
- molar: 59% in coronal, middle third
76% at furcation
accessory canals: found at?
apical region
anatomy of the root apex:
apical preparation should end at?
where is the apical constriction?
apical foramen found where in relation to anatomical apex?
- apical preparation should end at the narrowest part of the canal
- 0.5-1mm from the apical foramen
- apical foramen rarely coincides with anatomical apex, mean distance is 0.2 - 2mm away
distance of apical constriction from radiographic apex: how does it vary in older people? why?
the distance (between apical constriction & radiographic apex) increases in older teeth with secondary cementum
stages of RCT: before starting treatment - what to do? what to study and take note of?
- full clinical examination + special investigations
- periapical radiograph: show apex, 2-3mm of surrounding periradicular tissues
study anatomy of RC:
- angulation of root in relation to adjacent teeth
- check for complications e.g. pulp stones, sclerosed and curved canals
- periradicular radiolucency present?
why must all caries and defective restorations be removed and replaced by a temporary restoration?
to prevent it from leaking during treatment
LA in endo treatment: which are the 3 to use? and why should each be used?
- prilocaine hydrochloride with felypressin (Citanest 3% w/ octapressin)
- used to avoid adrenaline, latex/preservative allergy, avoid in pregnancy
- lidocaine hydrochloride 2% with adrenaline 1:80,000
- used for most injections, avoid if unstable angina, severe cardiac dysrhythmia, allergy, caution with other cardiac conditions
- articaine hydrochloride 4% with adrenaline 1:100,000
superior diffusability through bone, risk of parasthesia
reasons for LA failure?
- poor technique
- inadequate amount of LA
- variation in patient’s anatomy
- very inflamed tissue/bone
- variation in absorption, metabolism and excretion of LA
- psychological factors
difficulties with anaesthesia? x4
apprehension _ anxiety
tiredness
tissue inflammation, vital pulps
previous unsuccessful anaesthesia
teeth with irreversible pulpitis:
what state?
inflamed tissue: how are they altered?
changes can affect where?
- state of hyperalgesia
- inflamed tissues may alter the nerve’s resting potential, therefore decreasing excitability thresholds
- changes not just confined to pulp, can affect the entire neuronal pathway
supplementary injections: list x4
palatal
mental
infraorbital
intra-ligamental (PDL anaesthetic injection)
PDL anaesthetic injection - useful when? what kind of needle length? - LA is redirected where? - do not inject into \_\_\_? - what is a common after effect?
- useful in mandible when IDB not fully effective
- 27/30 short gauge needles, bevel orientated to root surface
- LA redirected NOT in apex, but into surrounding cancellous bone of the dental socket
- do not inject into inflamed periodontal tissues
- tenderness is common
intraosseous injection:
how is it done?
what is used?
where is it done?
- cortical bone perforated by creating small hole between roots of teeth
- special rotary instrument, light pecking motion
- 5mm apical to the buccal papilla
intraosseous injection: x-tip used for? how much of cartridge used? how long onset? not suitable if? what is a side effect if vasoconstrictor used?
- x-tip leaves guide in place to make it easer to insert needle
- one quarter to half a cartridge
- rapid onset, up to 60mins if vasoconstrictor used
- not suitable for gross periodontal disease or acute periradicular infection
- may be a transient increase in heart rate if using vasoconstrictor
intra-pulpal injection
- best used if?
- why need to warn patient before?
- best used in pulp chamber is very small
- it can be very pain
computer controlled LA: market name?
LA given at what rate?
The Wand STA
LA given at slow rate
