Comparison of Er:YAG laser and surgical drill for osteotomy in oral surgery: an experimental study.
OBJECTIVE
High-energy lasers have been proposed as an alternative to the conventional surgical drill in oral and maxillofacial surgery. The aims of this study were to compare thermal changes of the bone surface, procedure time, and volume of the removed bone after drilling with an erbium (Er):yttrium-aluminum-garnet (YAG) laser versus a low-speed surgical drill. The bone sections were observed under light microscopy and examined histologically.


METHODS
Thirty bone blocks were prepared from porcine ribs. On each block 2 holes (tunnel preparations) were performed using a low-speed, 1.0-mm-wide, surgical pilot drill and an Er:YAG laser (pulse energy, 1,000 mJ; pulse duration, 300 μs; frequency, 20 Hz). The temperature induced by the preparation techniques was measured using an infrared camera. The removed bone volume was calculated by a modified mathematical algorithm. The time required for the preparation was measured with a digital stopwatch and a time-measurement instrument integrated within the computer program. The cortical and spongiose surfaces of the specimens were examined microscopically and histologically under a light microscope with a high-resolution camera.


RESULTS
The Er:YAG laser removed significantly more bone tissue than the drill (P < .01) in a significantly shorter time (P < .01). The temperature was statistically lower during the laser preparation (P < .01). Cavities prepared with the laser were regular with clear sharp edges and knifelike cuts. In the drill group, the preparations exhibited irregular edges full of bone fragments and fiberlike debris. Histologic examination of the laser sides showed a 30-μm-thick altered sublayer. The tissue in the drill group was covered with a smear layer without any alterations.


CONCLUSIONS
The Er:YAG laser produced preparations with regular and sharp edges, without bone fragments and debris, in a shorter time, and with less generated heat. Thermal alterations in the treated surface were minimal.
Department of Oral Surgery, School of Dental Medicine, University of Zagreb, Zagreb, Croatia.
Dragana
D
Gabrić Pandurić
Ivona
I
Bago
Davor
D
Katanec
Janez
J
Zabkar
Ivana
I
Miletić
Ivica
I
Anić
D000818:Animals; D001831:Body Temperature; D001842:Bone and Bones / Q000601:surgery; D003762:Dental Instruments; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D061646:Operative Time; D019647:Oral Surgical Procedures / Q000295:instrumentation*; D010027:Osteotomy / Q000295:instrumentation*; D012272:Ribs / Q000601:surgery; D016369:Smear Layer; D034421:Sus scrofa