1.A 28- year- old man attends with a continuous aching pain from his upper left first permanent molar (UL6). It occurs spontaneously, disturbs sleep, and is partly relieved by paracetamol. Chewing or biting does not exacerbate the symptoms. The heavily restored UL6 was hyperresponsive to refrigerant (EndoFrost ® ). All other special investigations were normal. Which is the single most likely diagnosis?
A Acute apical abscess
B Atypical facial pain
C Chronic apical periodontitis
D Irreversible pulpitis
E Periodontal abscess
Answer : D
No TTP when chewing → exclude apical periodontitis and apical abscess. But TTP is also noted in irreversible pulpitis sometimes.
- A 45- year- old man has sharp pain to cold from his upper right posterior teeth; the pain ceases immediately on removal of the stimulus. He has multiple cervical abrasion cavities. Which single type of sensory nerve fibre is primarily responsible for his pain?
A A- β
B A- δ
C C
D Parasympathetic
E Sympathetic
Answer : B
#Aδ – myelinated nerve fibres responsible for sharp/shooting pain (dentin hypersensitivity & reversible pulpitis . Aδ takes up 90% of A fibres and is the narrowest A , fibres, but still larger than C fibres
#C fibres – unmyelinated,innervates pulp, has slow conduction, responsible for aching pain (irreversible pulpitis)
#Aβ involve in nociception, less degree than Aδ #Sympathetic nerve fibres mediates circulation
- A 29- year- old woman is about to have primary root canal treatment on her lower right first permanent premolar (LR4). Figure 5.1 shows burs selected by the clinician during root canal preparation. At which single stage of root canal prep would it be most appropriate to use this?
A Access
B Apical preparation
C Canal identification
D Coronal flaring
E Working length determination
Answer : D
Coronal flaring helps improve access to apical region; remove infected tissue; improve irrigant placement; and improve accuracy in assessing WL. It also reduces file separation by decreasing the stress placed upon files when preparing the apical portion of the root canal.
- A 45-year-old man is having root canal treatment on his upper left first premolar. After scouting the canal with a small hand file, a rotary file system is introduced with an ISO 25 tip size and a 10-degree taper (25/.10) until resistance is felt. Subsequently, files with a smaller taper are introduced until the working length is reached (25/.06 → 25/.04). What single concept of endodontic preparation does this technique follow?
A Apico-coronal
B Circumferential
C Crown-down
D Modified double flare
E Step back
ANswer : C