Thermal necrosis-aided dental implant removal: A rabbit model pilot study

The significant advances in the materials and biological aspects of dental implants haven't completely eradicated the implant failures. The removal of osseointegrated but otherwise failed implants present several challenges including adjacent tissues damage and necessity of bone augmentation for reimplantation. Controlled thermal necrosis has emerged as an alternative technique to aid removal of osseointegrated dental implants with minimal to no defect to healthy bone or surrounding tissues. This study aimed to evaluate the thermal necrosis-aided implant removal method in a rabbit osseointegration model.

A total of 8 male New Zealand rabbits were used in the study. Two dental implants were placed on each femur of the rabbits. Heating of the implants was performed after 7 weeks following the implantation. Heating was done by contacting the tip of an electrosurgey tool in monopolar mode at different power settings and contact durations (5W - 2 seconds, 5W - 10 seconds, and 10 W - 10 seconds). No heating was done on the control group. Implant stability right after implantation, before heat application and after heat application was determined using an Osstell™ Mentor Device. Following the removal of implants histological analyses were performed to determine the effects of heat application at cellular level.

ISQ values of the 10W-10s group was significantly lower compared to the other groups (p<0.001). No indication of progressive necrosis or irreversible damage was observed in any of the groups. However, the percent of empty-apoptotic lacunae were statistically higher in the 5W-10s and the 10W-10s groups compared the control and the 5W-2s groups.

Within the conditions of this study, we conclude that heat application with an electrosurgery tool using monopolar mode at 10W power for 10 seconds is optimal for reversing osseointegration with no extensive or progressive damage to the bone.