Differential Temperature Produced by Er,Cr:YSGG-Laser Irradiation on Ceramic Implants

Objectives: The aim of this study was to determine the differential temperature produced on ceramic implants during Er,Cr:YSGG-laser irradiation of intrabony defects in an in-vitro model.
Methods: A ceramic (Zr) dental implant (Zeramex, 4.8x12mm) was placed into a bovine bone block. A 3-wall intrabony defect (6x4x3mm) was created to simulate a peri-implant lesion. Thermocouples were secured to the apical and coronal areas to measure temperature changes (ΔT) during 60 sec irradiation period. The bovine block was heated to 37°C and the defect walls were irradiated with the Er,Cr:YSGG-laser. The settings used were pulsed mode (30Hz, 1.5W, air: 40%, water: 50%) (Group A). The same laser settings and irradiation procedure were repeated at room temperature (RT, 23°C) (Group B). Twenty trials were performed for each experimental group at room and body temperature with the use of water during irradiation and without for assessment of ΔT. Games-Howell Simultaneous Tests were used to compare the measurements between 37°C and 23°C.
Results: The greatest positive ΔT was observed in coronal and apical thermocouples at RT (both 30 and 60 seconds) irradiated without water. At 37°C, there was a negative ΔT when water was used during irradiation. The ΔT for both groups is presented in the Table.
Conclusions: Within the limitations of this study, the use of Er,Cr:YSGG-laser on peri-implant defects generally seems to be safe, but sufficient cooling should be applied to avoid overheating of zirconia implants.