THERMAL ASPECTS OF SELF-CURING POLYMETHYLMETHACRYLATE

TLDR

Bone necrosis adjacent to self‑curing polymethylmethacrylate is a well‑documented phenomenon, but evidence indicates that thermal damage from polymerisation is unlikely to be the cause and is not a significant factor in prosthetic fixation failure. Interface temperatures during polymerisation are governed mainly by the surface area of contact and the thermal properties of the adjacent cooler material. Measured temperatures within polymerising acrylic masses correlate with the amount of monomer polymerised and are clinically insignificant for prosthesis fixation.

Abstract

Bone necrosis adjacent to self-curing polymethylmethacrylate is a matter of accepted fact. Among the possible causes are mechanical and vascular damage from the preparation of the bone cavity, chemical damage from the monomer and free radicals in the cement dough, and thermal damage from the heat of polymerisation, occurring in this order. Consideration of the tissue reaction to this material, theoretical calculation of the heat output from polymerising acrylic and interface temperature profiles, experimental observations of interface temperatures and maximal temperatures at polymerisation, together with clinical observations, all lead to the view that the bone necrosis is not a consequence of thermal damage, which is unlikely to be a cuase of failure of prosthetic fixation. Temperatures recorded from within polymerising acrylic masses are related primarily to the amount of monomer polymerising and are of no clinical significance in the fixation of prostheses. Interface temperatures are related primarily to the surface area of the interface and the thermal characteristics of the cooler material.