Effects of LED phototherapy on bone defects grafted with MTA, bone morphogenetic proteins and guided bone regeneration: a Raman spectroscopic study

Abstract

We studied peaks of calcium hydroxyapatite (CHA) and protein and lipid CH groups in defects grafted with mineral trioxide aggregate (MTA) treated or not with LED irradiation, bone morphogenetic proteins and guided bone regeneration. A total of 90 rats were divided into ten groups each of which was subdivided into three subgroups (evaluated at 15, 21 and 30 days after surgery). Defects were irradiated with LED light (wavelength 850 ± 10 nm) at 48-h intervals for 15 days. Raman readings were taken at the surface of the defects. There were no statistically significant differences in the CHA peaks among the nonirradiated defects at any of the experimental time-points. On the other hand, there were significant differences between the defects filled with blood clot and the irradiated defects at all time-points (p < 0.001, p = 0.02, p < 0.001). There were significant differences between the mean peak CHA in nonirradiated defects at all the experimental time-points (p < 0.01). The mean peak of the defects filled with blood clot was significantly different from that of the defects filled with MTA (p < 0.001). There were significant differences between the defects filled with blood clot and the irradiated defects (p < 0.001). The results of this study using Raman spectral analysis indicate that infrared LED light irradiation improves the deposition of CHA in healing bone grafted or not with MTA.

Repair of Surgical Bone Defects Grafted with Hydroxylapatite + β-TCP and Irradiated with λ=850 nm LED Light

“…These features were observed in many studies in which this group used similar parameters to the ones carried out with Laser Phototherapy (LPT) or LED-PT (2)(3)(4)(5)(6)(7)(8). It seems that the beneficial effects of LED-PT are similar to those of the laser.…”

“…This association may modulate the repair of bone defects in a manner similar to what is observed following the use of autologous bone graft, preventing its complications and limitations (2,4,5,8,11,12). However, the use of autologous grafts remains the gold standard for the treatment of bone defects (2,3).…”

“…Total energy delivered was 20 J/cm 2 per session and 140 J/cm 2 per treatment. Energy densities used were based upon previous studies carried out by the authors (1)(2)(3)(4)(5)(6)(7)(8)11,12). LED output power was confirmed by using a calibrated power meter (Thorlabs PM30-121; Thorlabs GmbH, Munich, Germany).…”

“…It is possible that the mechanism involved is similar to the light absorption by the cytochrome-C-oxidase present in the mitochondrial membrane (9,10). Despite the increase of successful reports of applications of different phototherapies in many areas, their use in bone repair associated with bone grafting with biomaterials needs to be further studied (4)(5)(6)(7)(8).…”

LED phototherapy on midpalatal suture after rapid maxilla expansion: a Raman spectroscopic study

“…However, most studies in regard to laser therapy with suture expansion have different protocols as to total dosage, time, mode and frequency of irradiations, which are factors that influence final results and prevent precise comparisons between studies. The use of LED has also been related to positive biostimulating effects similar to those obtained when laser is used [12][13][14] .…”