Implant removal using thermal necrosis-an in vitro pilot study

Objectives The purpose of this pilot porcine cadaver study was to evaluate the feasible temperature thresholds, which affect osteocyte viability and bone matrix in a preclinical setup, assessing the potential of thermal necrosis for implant removal for further in vivo investigations. Materials and methods After implant bed preparation in the upper and lower jaw, temperature effects on the bone were determined, using two tempering pistons with integrated thermocouples. To evaluate threshold temperature and time intervals leading to bone necrosis, one piston generated warm temperatures at 49 to 56 degrees C for 10 s and the other generated cold temperatures at 5 to 1 degrees C for 30 s. Effects were assessed by a semi-quantitative, histomorphometrical scoring system, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). Results The bone matrix was significantly degenerated starting at 51 degrees C for 10 s and 5 degrees C for 30 s. The osteocyte condition indicated significant bone damage beginning at cold temperatures of 2 degrees C. Temperature inputs starting at 53 degrees C led to decalcification and swollen mitochondria, which lost the structure of their inner cristae. Conclusions This study identified temperatures and durations, in both heat and cold, so that the number of samples may be kept low in further studies regarding temperature-induced bone necrosis. Levels of 51 degrees C for 10 s and 5 degrees C for 30 s have presented significant matrix degeneration.

Automated summary

This pilot study identified temperature thresholds and durations, both in heat and cold, which induce bone necrosis, aiming to reduce the number of samples needed in further investigations on temperature-induced bone necrosis. Temperature inputs starting at 51 degrees C for 10 s and 5 degrees C for 30 s have shown significant matrix degeneration.