Spreader load required for vertical root fracture during lateral compaction ex vivo: evaluation of periodontal simulation and fracture load information

Objective To evaluate the biomechanical influence of the periodontium on spreader load measuring required for vertical root fracture (VRF). Study design Fully developed permanent incisors (n = 32) from 4 fresh goat mandibles were used. All teeth were subjected to standardized root canal instrumentation and divided into 2 groups: Teeth of group A were tested within natural sockets, and teeth of group B were mounted in artificial sockets and then tested. Spreader was driven to standard depth repeatedly, and insertion load was recorded constantly until intentional VRF. Results Fracture load in group A varied from 5.9 kg to 25.1 kg, and in group B from 4.3 kg to 26.9 kg. No statistical difference was found between the 2 groups in terms of fracture load or plane of fracture ( P > .05). Conclusions Periodontal simulation by acrylic resin and elastomeric impression material was deemed to be reliable. The inability of fracture load to reveal information about crucial events of the phenomenon was evident.