Histologic effect of Low Level Laser Therapy on Bone Remodeling

Purpose:the aim of this study was to demonstrate the histologic effects of low level laser therapy (LLLT) on alveolar bone remodeling and socket preservation in dogs.

Material and Methods: Three premolars in every oral quadrant of five male beagle dogs were extracted and the resultant 60 bony sockets were examined for possible root fracture and organization of blood clot. Total of 56 sockets were randomly assigned to four different groups in this split mouth study. One side was randomly selected as control and the other side was irradiated on days 0,2,4,6,8 with 4j/cm2 laser (group 1), days 0,2,4,6,8,20,22,24,26,28 using 4j/cm2 laser (group 2) and days 0,2,4,6,8,20,22,24,26,28 using 2j/cm2 laser (group 3). Animals were sacrificed one month after day of extractions and histologic and histomorphometric evaluations of the slides was carried out under light microscope. Amount of inflammation, new bone formation, number of osteoclasts and number of osteoid cells in the newly formed bone were recorded.

Results: The amount of newly formed bone was significantly more in all of the groups comparing to the controls (P<0.01). The number of osteoid cells were also significantly greater in different groups comparing to the controls (P<0.05). groups showed no significant difference with the controls in the amount of inflamation and number of osteoclasts (P>0.05).

Conclusion: The irradiation of low energy laser significantly promotes remodeling of alveolar bone with increased number of osteoid cells and increased amount of regenerated bone.