1. A 52-year-old woman has a sudden onset of severe pain and an altered sensation under her eye, following irrigation during root canal retreatment on a maxillary canine. Which is the single most likely complication?
A Extrusion of sodium hypochlorite
B Inadvertent instrumentation of the infraorbital nerve
C Lateral perforation
D Root fracture
E Transportation of apical constriction
Answer : A
Irrigant normally reached 1-2mm beyond needle tip.
Precaution : side vented needle, gentle irrigation pressure, irrigating tip 2-3mm away from WL
2. A 28-year-old man is having an obturation of a permanent upper central incisor. A heated plugger (e.g. System-B®) is being used during the ‘downpack’. Which is the single most appropriate description of the obturation technique being used?
A Carrier-based thermoplasticized technique
B Cold lateral condensation
C Single cone obturation
D Thermoplasticized injection technique
E Warm vertical compaction
Answer : E
Cold lateral condensation – finger spreader compact master cone sideways to allow space for accessory point
Warm vertical compaction – heated plugger insert into WL, creating apical plug.
3. A 54-year-old man is having root canal treatment on an upper canine, using stainless steel hand files via the modified double flare technique. An ISO size 25 hand file is the first to bind at the working length. What should be the single most appropriate size of the master apical file (MAF)?
A ISO size 20
B ISO size 25
C ISO size 30
D ISO size 35
E ISO size 40
Answer : D
Modified double flare technique uses 2% ISO hand files and combines both crown down and step back. (like what abhi teach us – prep coronal ⅔ first then determine IAF. Clean till MAF and slowly increase file size and reduce length by 1mm each time till meet coronal ⅔
IAF – first file that binds at WL ‘gauges’ the size of apical constriction
Increase size by 2 size for MAF
4. A 47-year-old man is having root canal treatment on his upper first molar, which has curved roots. Following coronal preparation of the mesiobuccal canal, an electronic apex locator (EAL) is used and provides a reproducible reading. This is 2 mm shorter than the estimated working length (EWL) from the preoperative radiograph. What is the single most appropriate initial management?
A Obturate to the EWL and review
B Obturate to the EWL, followed by apicectomy
C Prepare using the reading of the EAL
D Take a new radiograph to check for potential perforations
E Take a parallax technique radiograph of the molar to identify the apex
Answer : C