to determine the ideal access location for mandibular incisors to get straight line access to the apical third and to determine if a correlation exists between the degree of incisal edge wear and location of access opening.
N= 279 extracted human mandibular incisors. ( central & lateral )
•The teeth were radiographed (bucco-lingual and proximal views for each tooth)
•From proximal images, each tooth was divided into coronal, middle and apical thirds.
•At the 2 junctions (coronal-middle thirds junction and middle-apical thirds junction), the canal width was measured and the midpoint between the buccal and lingual walls was determined.
•A line was drawn connecting the 2 midpoints and extending through the crowns to determine the ideal access location. (Fig. )
•The degree of teeth wear was recorded (slight or non, moderate, extensive) and chi-square test was used to assess the relationship between the incisal wear and the ideal access location
Most highlighted Results:
- 27.6% of the teeth had their ideal access facial to the incisal edges and 72.4% had straight line access on the incisal edges.
- The ideal access opening moved from the facial to the incisal edges as the amount of the incisal wear increases
- Non of the teeth had straight line access on the lingual surface.
The straight line access for mandibular incisors is always located incisally or facially & the amount of incisal wear can provide a guide for proper access location.