endodontic lab book Flashcards
Which teeth are commonly difficult for locating canals?
Upper first molars,
lower incisors,
lower canines,
lower first premolars,
lower first molars,
C-shaped molars.
What is the average length and canal anatomy of upper first molars?
22mm; 3 roots, 4 canals (MB2 sometimes joins MB1).
What is the average length and canal anatomy of lower incisors?
22mm; 1 root, 2 canals (40% of cases).
What is the average length and canal anatomy of lower canines?
27.5mm 1/2 canals
What is the average length and canal anatomy of lower first premolars?
23mm; 1 root, 2 canals (24%).
What is the average length and canal anatomy of lower first molars?
22mm; usually 2 roots, sometimes 3.
Describe the orifice in C-shaped molars.
Single ribbon-shaped orifice, arching from mesiolingual line angle to distal aspect of pulp chamber.
What is the law of symmetry in root canal anatomy?
Except for maxillary molars, canal orifices are equidistant from a line drawn mesio-distally through the pulp floor.
What is the color of the pulp chamber floor compared to the walls?
The floor is always darker.
Where are root canal orifices located?
At the junction of walls and floor, and at the terminus of root developmental lines.
What are signs of dentine hypersensitivity?
Sharp pain to cold/air; no radiographic changes; managed with OHI and fluoride.
What are signs of reversible pulpitis?
Sharp, short pain to hot/cold; exaggerated cold response; managed with temporary restoration and desensitisers.
What are signs of irreversible pulpitis?
Throbbing pain, lasts minutes-hours, poorly localized; managed with extirpation, RCT, or extraction.
What are signs of pulpal necrosis?
No symptoms, discolouration, negative sensibility tests; managed with RCT or extraction.
What is acute apical periodontitis?
Tenderness to bite; -ve sensitivity test; PDL widening; manage occlusion, access & dress.
What is chronic apical periodontitis?
Asymptomatic or mild ache, periapical radiolucency, -ve sensitivity test; managed by monitoring or RCT/extraction.
What is chronic apical periodontitis with acute exacerbation?
Dull, throbbing pain, percussion tenderness, radiolucency; access and calcium hydroxide dressing.
What are features of a periapical abscess?
Swelling, throbbing pain, -ve sensitivity, radiolucency; manage with access, drainage, and RCT or extraction.
What are the stages of endodontic treatment?
LA → Isolation → Access → Shaping & Cleaning → Obturation → Restoration.
Why is isolation important in endodontics?
Prevents contamination, protects airway and tissues, and ensures aseptic conditions.
hat is the overriding principle of Schilder’s shaping?
Create a shape we can irrigate and obturate.
What is the basic protocol for Protaper Gold instrumentation?
Coronal flare (SX, S1, S2) → WL with S1/S2 → F1 and F2 to WL → Irrigate and patency file between.
How is working length (WL) determined?
File to apex, watch for 0 reading on EAL, subtract 0.5mm from that.
When is irrigation most effective?
After canal shaping is complete.
Why use side-vented needles?
To prevent extrusion and injury.
How do we prevent sodium hypochlorite accidents?
Use rubber dam, measure files/syringes, avoid wedging needle, keep needle in motion.
What are signs of a sodium hypochlorite accident?
Pain, bleeding, swelling.
What is the immediate management?
Irrigate with saline, place calcium hydroxide, pain control with LA and analgesics.
How do you manage swelling or sequelae?
NSAIDs, steroids, antibiotics if needed; monitor and consider referral.
Why is a temporary restoration important?
Maintains a sterile environment between visits.
What is used for interappointment dressing?
Non-setting calcium hydroxide + cotton pledget + reinforced GIC.
When should a canal be obturated?
After disinfection, absence of symptoms, and canal is dry.
What are the aims of obturation?
Seal pulp space, prevent reinfection, block nutrient supply.
What are properties of an ideal root canal filling material?
Stable, easy to place/remove, biocompatible, radiopaque, antibacterial.
What are steps of cold lateral condensation?
Master cone fitting (tug back), dry canal, sealer, spreader + accessory cones, radiograph, coronal GP removal, RMGIC lining.
What are common problems during obturation?
Canal not dry, no tug back, GP bends or comes out, sealer sets too fast, root fracture, short fill, overfill, voids.
: When should restorability be assessed?
Before starting endodontic treatment.
What are the functions of restoring a RFT?
Prevent reinfection, protect tooth, restore function/aesthetics, maintain periodontal health.
What are the key symptoms of a sodium hypochlorite accident?
Sudden onset of acute pain, bleeding/haemorrhage from the root canal, and swelling within minutes to hours.
What is the immediate management of a sodium hypochlorite accident?
Irrigate the canal with saline, apply calcium hydroxide, place a temporary filling, ensure occlusion is not proud, and manage pain with analgesics.
What pain relief is recommended following a sodium hypochlorite accident?
: Paracetamol 1000mg up to 4x/day and Ibuprofen 400-600mg up to 4x/day
How is swelling managed following a sodium hypochlorite accident?
NSAIDs, consider steroids if swelling is rapid, and antibiotics if there’s pre-op swelling or tissue necrosis.
What follow-up protocol is recommended after a sodium hypochlorite accident?
Phone call same day, daily calls for a few days, then 1-2 times weekly; severe cases need longer follow-up and possible referral.
How can sodium hypochlorite accidents be prevented?
Use rubber dam, measure correct working length, safe-ended needles, passive syringe movement, use index finger not thumb, avoid locking syringe into canal, and use low concentration hypochlorite (0.5–5.25%).
When should the restorability of a root-filled tooth be assessed?
Before beginning endodontic treatment.
What are key factors in coronal tissue assessment?
Quantity (min. 1.5–2mm ferrule), thickness, and position of remaining tooth structure.
What occlusal considerations are important when restoring post-crowned teeth?
Posterior: only ICP contact. Anterior: incisal guidance shared across all anterior teeth. Post crowns shouldn’t provide canine guidance.
What are important aesthetic factors when restoring an RFT?
Tooth shape, shade, and any discolouration.
What is the primary purpose of a post?
To retain the core.
: Does post material affect tooth survival?
No, post material has no effect on survival rate.
What is the ideal post length?
Longer than the clinical crown with at least 4mm of gutta-percha remaining to preserve apical seal.
Should dentine be sacrificed to place a post with modern techniques?
No, adhesive technology avoids unnecessary dentine removal.
What types of posts are commonly used?
Tapered and parallel-sided direct posts (e.g. LDI).
What key elements should be included in endodontic records?
Provisional/definitive diagnosis, discussed treatment options, prognosis, informed consent (risks), and treatment records.
What risks should be communicated during consent for RCT?
Tooth fracture, damage, blocked canals, persistent infection, bleach leakage, and instrument fracture.
What happens in the first RCT appointment for a lower molar?
Confirm diagnosis, LA, rubber dam, remove caries/restoration, assess restorability, extirpation, dressing.
What occurs during the instrumentation appointment?
Re-access, chemo-mechanical prep, working length determination, irrigation, dressing, and temporisation.
What happens during the obturation/restoration appointment?
Master cone fitting, obturation with GP and sealer, post-op radiograph, core restoration (likely composite), use of matrix and wedge.
When is a preoperative radiograph taken and why?
Before treatment, to assess full root length and 2–3 mm periapical region.
When is a working length radiograph needed?
To determine accurate canal length—often multiple radiographs may be needed.
What is the purpose of a master point/master file radiograph?
To verify canal preparation and working length prior to obturation.
When is the post-obturation radiograph taken and what should it show?
After obturation—it should show complete fill of canal, intact apical seal, and no voids.
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