- Purpose: assess the presence and type of canal isthmus in first molars.
- N= 88 teeth (32 Max/ 56Mand) Exclusion criteria: medical condition contraindicated for oral surgical procedure with/ advanced marginal periodontitis, 2nd permanent molars
- Surgical procedure: OR, under LA triangular/trapezoidal flap was raised, affected roots resected 3-4 mm.
- Isthmus evaluation: after methylene blue staining rigid endoscope was placed.
- Number of canals and type of isthmus present was recorded.
- Isthmuses classification according to Hsu & Kim1.
Most highlighted Results:
- Most often treated root is mesial root of mandibular 1st molar.
- Mandibular molar isthmus present 83% in mesial root, mostly type IV,V and II. Isthmus present 36% in distal root, mostly type V.
- Maxillary molar isthmus present 76% MB root, mostly type II.
- Never present in Palatal and disto-buccal roots.
- None of the isthmuses were obturated by orthograde filling.
The importance of irrigation activation