Low-Level Laser Therapy for Implants Without Initial Stability

Abstract

This study evaluated the effect of low-level infrared laser on removal torque values of implants with poor initial stability inserted in rabbit tibias. It is important to analyze the effects of laser radiation on bone repair when low-quality bone and implants with poor initial stability are used. Thirty male white New Zealand rabbits (Oryctolagus Cuniculus) about 2 mo old and weighing 1.5-2.0 kg were used. Machined implants with poor initial stability were inserted in the tibia of each animal. Animals were randomly divided into two groups: laser irradiated and laser nonirradiated. Each group was further divided into three subgroups, according to the day the animals were killed: 15, 30, or 45 d. Torque values were measured with an axial digital torquemeter that applied counter-torque. The Student's t-test was used to calculate means and standard deviations for the comparisons between laser and control groups. A significant increase (p = 0.050) in removal torque values was found in the group of laser-irradiated implants at 15 and 30 d when compared with the control groups. At 45 d, no significant differences were found. In this study, low-level laser therapy promoted the osseointegration of implants with poor initial stability, particularly in the initial stages of bone healing.