Application of Photobiomodulation Therapy of Neodymium-Doped Yttrium Aluminum Garnet Laser for Implants as Measured by Reconstructed Three-Dimensional Analysis of Micro-computed tomography Images

Abstract

Objective:

This study evaluated how photobiomodulation caused by laser irradiation influences the osseointegration of titanium dental implants installed in rat tibiae.

Materials and Methods:

A titanium implant was inserted after a bone defect was created in each tibia of 18 rats. The right tibia was treated with low-level laser therapy (LLLT) using a Nd:YAG laser (LT group) every other day until sacrifice, with the opposite side serving as a control (Control group). At 2, 3, and 4 weeks after implantation, tibiae were collected, and a torque test was performed. After performing X-ray and micro-computed tomography, bone volume (BV) and bone mineral density (BMD) of new bone formation in the defects after implant removal were calculated from three-dimensional images, and all tibiae were analyzed histologically.

Results:

BV and BMD were highest in the LT group at 2 weeks and decreased at 3 and 4 weeks. Removal torque values in both groups were lowest at 2 weeks and increased at 3 and 4 weeks. There were significantly higher removal torque values of the LT group than in the Control group at 2 and 3 weeks, whereas no significant differences between groups were evident at 4 weeks. This suggested that LLLT using a Nd:YAG laser significantly accelerated bone formation during the healing process at 2 weeks, and osseointegration between bone and the implant body may have been enhanced at 2 and 3 weeks.

Conclusions:

Nd:YAG laser therapy appears effective for promoting bone formation and osseointegration of implants in rat tibiae.