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.