engleski

Termical and voluminous bone effect comparison between Er-YAG laser and cortical drill- an experimental study

Background and Aim: Mechanically rotating instruments such as drills or mills for bone treatment have the disadvantage of damaging the surrounding bone by the generated frictional heat. Cooling of the instrument cannot avoid this damage completely. Laser systems are an alternative solution for bone removal. Areas of application for bone treatment laser systems are the dental implantology, bone surgery and osteotomy. The aim of presented experimental study was the comparison of temperature caused bone surface changes and removed bone volume after bone treatment with the Er-YAG laser and cortical drill. Methods and materials: An experimental study was performed on the 10 pig ribs. Each rib was prepared with sagital osteotomy to get two equal parts of the rib. Each part then was separated in equal plates. All plates had the similar thickness of cortical and spongious bone mutually. The idea was to simulate the height and the width of intraoral autologous bone blocks commonly used in bone management in dental implantology. Calibration of the laser parameters was done. Each plate was treated with the erbium-YAG laser with a sapphire tip on a contra-angle hand piece with a 0.9mm diameter glass fiber in a max mode (with 1000mJ and 20 Hz) to make bone site within the full thickness of the plate. The other preparation was made next the previously prepared laser site with the 1.0mm cortical drill, commonly used for the fixation screws preparations, at 40 000rpm with simultaneous saline irrigation. The drill rotation was higher to achieve the same level with calibrated lasers parameters. Results: Surface termical changes were measured with infra-red camera in the whole interval of the bone exposure and preparation period. The removed bone volume for each exposure and preparation was calculated by modified mathematical algorithm. Time of the laser bone exposure was within the 15 seconds, and drill preparation within 60 seconds. The removed bone volume was higher in the laser group, and needed considerably less time, which resulted in minor termical surface changes (some amorphous surface tissue caused by the carbonization of bone during the laser exposure), in comparison with the cortical drill preparation usually caused by extended preparation time. Conclusions : In comparison with the cortical drill preparation, the possibility of using Er-YAG laser in future clinical cases of bone surgery and dental implantology can be considered efficient without inducing irreversible bone damages.

oral surgery; dental implants; laser; surgical drill; bone

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