Fabrication of a customized tray for preventing fracture of isolated abutment teeth in definitive casts.

Isolated abutment teeth with advanced bone resorption on definitive casts for a partial removable dental prosthesis can fracture when the definitive cast is removed from the impression or during subsequent laboratory procedures. This report describes a technique that avoids fracture of the definitive cast during its fabrication. A separating line is formed on the custom tray, which enables removal of the definitive cast without fracturing the isolated tooth. In addition, if the cervical line is sharp and appears compromised, then the impression can be trimmed at the clinical cervical line to enlarge the abutment diameter and increase its resistance to fracture without altering the shape of critical areas.