
Diagram of the apparatus redrawn for clarity, which has been originally developed by Ralph (1982) [14] and has been modified by Mandel et al. (1986) [12]. A transverse section of a tooth root fastened between two metal plates is immersed in phosphate-buffered saline (PBS). The plates are fixed by screws within a chamber, which is mounted in a materials testing machine. As the chamber moves upwards at a constant speed, the periodontal ligament (PDL) is loaded by metal rod connected to a load cell of the machine. B: bone; D: dentine; P: dental pulp.