applied fracture mechanics

Fracture of Dental Materials 115Figure 7. The bottom left drawing shows the orientation of the rods along the long axis of the tooth. Asseen from both drawings, there is a continous shift in orientation resulting in the S-shaped orientation.If the line joining points 1, 11 and 21 along the S-shaped curve represents a plane forming 90 degrees tothe enamel surface, it is seen from the drawing that there is a difference in rod orientation that can bedescribed as 90 ± 10 degrees. Redrawn from [2].The pulp chamber is a cavity inside the dentin formed by the surrounding dentin. The pulpchamber contains soft tissue, blood vessels and nerves and is lined by the odontoblasts. Asthe tooth grew older, the odontoblasts continue to produce dentin, causing the size of thepulp chamber to decrease with age.