The efficacy of the use of IR laser phototherapy associated to biphasic ceramic graft and guided bone regeneration on surgical fractures treated with wire osteosynthesis: a comparative laser fluorescence and Raman spectral study on rabbits

Abstract

The aim of the present study was to assess, by Raman spectroscopy and laser fluorescence, the repair of surgical fractures fixed with wire osteosynthesis treated or not with infrared laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) =16 J/cm(2), ϕ=0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration. Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into five groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet, and had water ad libitum. The fractures in groups II, III, IV, and V were fixed with wires. Animals in groups III and V were grafted with hydroxyapatite (HA) and guided bone regeneration (GBR) technique used. Animals in groups IV and V were irradiated at every other day during 2 weeks (4 × 4 J/cm(2), 16 J/cm(2) =112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken and kept in liquid nitrogen and used for Raman spectroscopy. The Raman results showed basal readings of 1,234.38 ± 220. Groups WO+B+L showed higher readings (1,680.22 ± 822) and group WO+B the lowest (501.425 ± 328). Fluorescence data showed basal readings of 5.83333 ± 0.7. Groups WO showed higher readings (6.91667 ± 0.9) and group WO+B+L the lowest (1.66667 ± 0.5). There were significant differences between groups on both cases (p<0.05). Pearson correlation was negative and significant (R (2) = -0.60; p<0.001), and it was indicative that, when the Raman peaks of calcium hydroxyapatite (CHA) are increased, the level of fluorescence is reduced. It is concluded that the use of near-infrared lasertherapy associated to HA graft and GBR was effective in improving bone healing on fractured bones as a result of the increasing deposition of CHA measured by Raman spectroscopy and decrease of the organic components as shown by the fluorescence readings.

NIR light-assisted phototherapies for bone-related diseases and bone tissue regeneration: A systematic review

“…Several studies have demonstrated that NIR light irradiation therapy could be used to improve bone healing and the regeneration process. NIR light therapy at 790 nm was reported to guide bone tissue regeneration on rabbits' tibial fractures with wire osteosynthesis or internal rigid fixation 122 - 124 . In addition, 850 nm NIR light phototherapy demonstrated the same ability to stimulate cell proliferation and guide bone tissue regeneration in a rodent model 125 .…”

Biomechanical Properties: Effects of Low-level Laser Therapy and Biosilicate® on Tibial Bone Defects in Osteopenic Rats

“…Some studies have showed that laser therapy is able to increase bone cell proliferation and to stimulate cell osteogenic properties (21-23). LLLT creates a number of environmental conditions that accelerate the healing of bone fractures and defects.…”

Future of bone pathology, bone grafting, and osseointegration in oral and maxillofacial surgery: how applying optical advancements can help both fields

“…The effects of near-infrared LPT have shown to demonstrate physiological stimulation of the fractured site. 18 This was proven to be effective as measured by Raman spectroscopy, which showed an increasing deposition of calcium hydroxyapatite, and by fluorescent reading, which showed a decrease in the organic components. 18 Studies have also shown that bone irradiated at the infrared (IR) wavelength demonstrates increased osteoblastic proliferation and activity and collagen deposition as well as a greater percentage of new bone formation when compared with bone that is not irradiated.…”

“…18 This was proven to be effective as measured by Raman spectroscopy, which showed an increasing deposition of calcium hydroxyapatite, and by fluorescent reading, which showed a decrease in the organic components. 18 Studies have also shown that bone irradiated at the infrared (IR) wavelength demonstrates increased osteoblastic proliferation and activity and collagen deposition as well as a greater percentage of new bone formation when compared with bone that is not irradiated. 19 Low-level laser therapy (LLLT) combined with BMPs and guided tissue regeneration has also been effective in improving bone healing.…”