High-intensity Nd:YAG laser accelerates bone regeneration in calvarial defect models

J Tissue Eng Regen Med. 2015 Aug;9(8):943-51. doi: 10.1002/term.1845. Epub 2013 Nov 19.

Abstract

High-power pulsed lasers have been recently regarded to be anabolic to bone, but in vivo evidence is still lacking. This study aimed to investigate the capacity of bone repair using a high-power, Q-switched, pulsed, neodymium-doped yttrium aluminium garnet (Nd:YAG) laser, using bilateral calvarial defect models having non-critical sized, 5 mm (rat) or 8 mm (rabbit) diameter. One of the bilateral defects, which were all filled with collagen sponge or left empty, was irradiated with a Nd:YAG laser once every 2 days for 2 weeks at a constant total fluence rate (344 J/cm(2) ), output power (0.75 W), pulse repetition rate (15 pps) and wavelength (1064 nm) and examined for the laser effect. The same experimental scheme was designed using a rabbit calvarial defect model implanted with sponge, which was explored for the dose effect of output power at 0.75 and 3 W with the same quantities of the other parameters. New bone formation was evaluated by micro-computed tomography-based analysis and histological observation at 4 weeks after surgery. Laser irradiation significantly increased new bone formation by approximately 45%, not only in the sponge-filled defects of rats but also when the defects were left empty, compared to the non-irradiated group. Consistently, both doses of output power (0.75 and 3 W) enhanced new bone formation, but there was no significant difference between the two doses. This study is one of the first to demonstrate the beneficial effect of Nd:YAG lasers on the regeneration of bone defects which were left empty or filled with collagen sponge, suggesting its great potential in postoperative treatment targeting local bone healing.

Keywords: Nd:YAG laser; bone regeneration; calvarial defect; collagen sponge; high intensity; high power.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aluminum
  • Animals
  • Bone Regeneration / radiation effects*
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / radiation effects*
  • Collagen / chemistry
  • Fracture Healing
  • Imaging, Three-Dimensional
  • Lasers
  • Lasers, Solid-State*
  • Male
  • Neodymium
  • Rabbits
  • Rats
  • X-Ray Microtomography
  • X-Rays
  • Yttrium

Substances

  • yttrium-aluminum-garnet
  • Neodymium
  • Yttrium
  • Collagen
  • Aluminum