Ideal endodontic access in mandibular incisors

Straight-line access in mandibular incisors facilitates locating and debridement of the canals. The purpose of this study was to plot where ideal access should be located in mandibular incisors to obtain straight-line access to the apical third of the root canal and to determine if a correlation exists between incisal edge wear and position of access opening. Two hundred and seventy-nine mandibular incisors were radiographed in clinical and proximal views. Straight-line access was determined by finding midpoints in the canal at two levels and extending a line connecting the points through the crown. Teeth were graded as to the condition of the incisal edge. Ideal straight-line access was determined to be at the incisal edge in 72.4% of the teeth, whereas in 27.6% of the teeth it was to the facial of the incisal edge. As the wear of the incisal edge increased, the ideal access moved from the facial toward the incisal.