engleski

Scaninng electron microscopy analysis of bone removal using Er:YAG and surgical drill

Intraoral bone grafting procedures are mainly performed using conventional instruments like drills, burs or saws. Major drawbacks of these techniques are mechanical pressure and vibrations on the bone, limited cut geometry caused by shape of the device, remnants of osseeous debris in adjacent soft tissue possibly leading to infections, the risk of accidental trauma to soft tissue. In recent years, high-energy lasers have been introduced in bone surgery. Haemostatic and aseptic effects, absence of mechanical stress and intricate cut geometry are potential beneficial aspects of non-contact osteotomy with infrared lasers. Aim of the presented study was to examine the morphological features and thermal-induced surface changes after Er:YAG ablation and drilling bone treatment. The experimental study was performed on 30 bone blocks prepared from pig ribs, simulating the height and the width of intraoral autologous bone blocks commonly used in dental implantology. The main idea was to simulate hole-like preparations for the fixation screw site.For the osteotomies, the Er:YAG laser (AT Fidelis, Fotona, Slovenia) and surgical pilot drill (Screw System, Hager&Meisinger GmbH, Germany) were used. Laser was applied with the 0.9mm spot size in non-contact max mode (1000mJ, 20Hz) and the handpiece was kept at a distance of 10mm from the bone surface to make bone site within the full thickness of the plate. Drill osteotomy was performed with the 1.0mm wide pilot drill, commonly used for the fixation screws preparations, at 15 000rpm, with simultaneous saline irrigation. Analysis of both hole's surfaces using scanning electon microscopy (Field Emission Scanning Electron Microscope, JSM-7000F, Japan) were performed. Er:YAG laser ablation produced a groove with similar dimensions to that produced by bur drilling. SEM observations revealed that the groove produced by the Er:YAG laser had well-defined edges and a smear layer-free surface with a characteristically rough and tearing appearance, with entrapped fibrin-like tissue and spherical formations. The melting and carbonisation were not observed on sited irradiated with Er:YAG laser. At the border of ablation groove, thermal changes were not found. In the case of drill osteotomy, the smooth surface covered with the smear layer with micro-fractures embadded was observed. At the border of ablation groove, irregular edges with hairy-like appearance were found. No thermal changes on drilling sited were found. Er:YAG laser may be considered an possible tool and effective method in clinical dental implantology and at the specified parameters may become applicable as an alternative method for bone surgery.

dental implantology ; SEM ; laser ; drill

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