The Influence of Low-Level Laser on Osseointegration Around Machined and Sandblasted Acid-Etched Implants: A Removal Torque and Histomorphometric Analyses
Evaluation of the influence of laser application on osseointegration around implants with different surface characteristics is limited. This study aims to evaluate the influence of low-level lasers on the early stages of osseointegration. Ninety-six external hex implants (3.75 mm × 5.0 mm) were placed in 24 rabbits—one machined and one sandblasted acid-etched per tibia. The rabbits were later divided into the laser group, which received a total dose of 24 J/cm2 of gallium-aluminum-arsenide laser over 15 days, and a control group. At 16 and 30 days after surgery, removal torque and histomorphometric analyses were performed. No statistical differences in removal torque or histomorphometric analyses were verified between laser and control groups regardless of implant surface (P > .05). Time was the only variable presenting significant differences between measurements (P < .05). Low-level laser had no significant short-term effect on bone-to-implant contact and removal torque values regardless of implant surface characteristics.
Description of the surgical procedure. (a) Preparation of the implant sites at the tibial diaphysis. (b) Surgical sites prepared approximately 10 mm apart. (c) Implants inserted at 15 rpm/35 Ncm torque. (d) Implants stabilized at the tibial upper cortical bone.
Figure 2. Histological specimens ground and polished at 10–20 μm thickness. Aspects of the upper (a), middle (b), and lower (c) portions of each implant were magnified at 10× for histomorphometry. Figure 3. Details of the osseointegration in control (a) and laser (b) groups at ×400 magnification (toluidine blue). Yellow, blue, and white arrows indicate Harvesian canals, Volkmann's canals, and newly formed bone toward the sandblasted acid-etched implant surface, respectively. Orange star illustrates the presence of bone marrow. Figure 4. Histological aspects of the bone formation in the control (a) and laser (b) groups. Note the differences in diameter of the Haversian canals between groups and the presence of osteocytes positioned in its surroundings, at ×1000 magnification (toluidine blue).
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