Integrated Dose-Effect Relationship of Near-Infrared Light-Emitting Diode Light on Bone Regeneration in Disuse Osteoporosis Rats.

Objective: To examine the integrated dose-effect relationship of near-infrared (NIR) light-emitting diode (LED) light therapy in promoting bone defect repair in the rat model for osteoporosis (OP). Background: Low-intensity laser therapy has been shown to promote bone regeneration in OP rats. However, its integrated dose-effect relationship is not clear. Methods: Twenty-week-old male Sprague-Dawley rats were randomly assigned to 11 groups: (1) no-treatment control group (C group), (2) tail suspension (TS)-induced disuse OP experimental group (TS-OP group), and (3) OP rats with LED light treatment at nine dosages (L1-L9 groups). The tail of the rat was tied and suspended on the beam of the cage to suspend their hind limbs to induce bone loss for 4 or 7 weeks. The rats were then released and returned to their regular positions. An NIR LED at 810 nm was used on the bilateral hind limbs daily for 4 weeks. The C group rats were not given any treatment. The TS-OP group rats were subjected to identical procedures with L groups, with the exception that the light power was not turned on. After the experiment, the dual-energy X-rays or the microcomputed tomography scan analysis was performed to evaluate bone tissue status. Data analysis was done using SPSS and the health scale. Results: The trabecular thickness, trabecular number, bone volume/total volume, and connectivity density of cancellous bone and the biomechanical properties of femur in light groups were significantly increased compared with the TS-OP group, while the trabecular separation and structure model index were significantly decreased. Conclusions: NIR LED light therapy may promote trabecular bone repair of TS-OP rats. Light intensity influences photobiomodulation. In our dose levels, the greater the light intensity, usually the more effective.

Effect of photobiomodulation therapy with different wavelengths on bone mineral density in osteoporotic rats.

Osteoporosis is associated with severe pain, bone deformity, fracture, and bone loss. It is important to find strategies to prevent bone resorption and treat osteoporosis. This study sought to assess the effect of photobiomodulation therapy (PBMT) with different wavelengths on bone mineral density (BMD) in osteoporotic rats. This animal study evaluated 63 adult female rats. The rats underwent ovariectomy to induce osteoporosis. Ovariectomized rats were randomly divided into 9 groups of control (OC), treatment with zoledronic acid alone (0.02 mg/kg), and treatment with 660 nm, 810 nm, and 940 nm PBMT alone (3 times a week for 6 weeks, energy density of 4 J/cm2), and combined with zoledronic acid. The healthy control group (HC) only underwent sham surgery. The rats underwent cone-beam computed tomography (CBCT) 52 days after the first treatment session to measure their BMD according to the gray value (GV) of images. To assess the biomechanical properties of bone, the resected bones were subjected to 3-point bending test (3-PBT). The experimental groups had significant differences with the OC group regarding radiographic and biomechanical properties of bone (P < 0.05), indicating a healing course. No significant difference was noted between the experimental groups treated with different laser wavelengths and those treated with zoledronic acid (P > 0.05). In the condition of this study, it was found that PBMT at a constant energy density of 4 J/cm2 with 660-, 810-, and 940-nm wavelengths is effective for enhancement of bone mineral density and biomechanical properties. No significant difference was noted between different wavelengths of diode laser regarding radiographic and biomechanical properties of bone.

Improvement in viability and mineralization of osteoporotic bone marrow mesenchymal stem cell through combined application of photobiomodulation therapy and oxytocin.

The probable positive effects of photobiomodulation therapy (PBMT) and oxytocin (OT) treatments together or alone were evaluated on cell viability along with the changes in the gene expression of Osteocalcin (OC), Osteoprotegerin (OPG), and Runt-related transcription factor 2 (Runx2) levels of sham (healthy)-Bone marrow mesenchymal stem cell(BMMSC) and ovariectomy-induced osteoporosis (OVX)-BMMSC. BMMSC was harvested from healthy and OVX rats and was cultured in osteogenic induction medium (OIM). There were five groups of BMMSCs: (1) sham -BMMSCs; (2) control -OVX-BMMSCs; (3) OT-treated-OVX-BMMSCs; (4) PBMT-treated-OVX-BMMSCs, and (5) OT + PBMT-OVX-BMMSCs. In all 5 groups, BMMSC viability and proliferation as well as gene expression of OC, OPG, and RUNX2 were evaluated. PBMT and PBMT + OT treatments showed a promising effect on the increased viability of OVX-BMMSC (ANOVA test; LSD test, p = 0.01, p = 0.002). The results of gene expression analysis revealed that the sham- BMMSCs responded optimally to OT treatment. It was also found that OVX-BMMSCs responded optimally to PBMT + OT and PBMT treatments at early and middle stages of osteogenic induction process. Nevertheless, they responded optimally to PBMT + OT and OT especially at the late stage of osteogenic induction process. PBMT and PBMT + OT treatments significantly increased viability of OVX-BMMSC in OIM in vitro. Both PBMT and PBMT + OT treatments could promote mineralization of OVX-BMMSC in the culture medium at early and middle stages of osteogenic induction process. Both OT and PBMT + OT treatments could promote mineralization of OVX-BMMSC in vitro at late stages of osteogenic induction process.

Beneficial effects of low-level laser irradiation on senile osteoporosis in rats.

OBJECTIVE: To investigate the effect of low-level laser irradiation (LLLI) on bone mineral density (BMD), bone structures, bone biomechanical properties and bone metabolism in senile osteoporosis, and to explore a relatively more secure and effective way to prevent and treat osteoporosis. MATERIALS AND METHODS: Sprague-Dawley (SD) male rats at different age stages (4 months old, 12 months old and 20 months old) were selected and randomly divided into six groups. The rats in the treatment group were treated with LLLI for 12 weeks, and then the microstructure of bones was analyzed by micro-computed tomography (micro-CT) scanning. The biomechanical indexes of the femur were detected by the three-point bending test. Levels of the blood calcium (Ca)2+, blood phosphorus (P)3+, urine Ca, urine P and urine creatinine (CREA) were detected using an automatic biochemical analyzer. The contents of serum osteocalcin (OCN) and bone alkaline phosphatase (BAP) were measured by enzyme-linked immunosorbent assay (ELISA). The bone formation rate (BFR) was analyzed by double fluorescent labeling with calcein and tetracycline. Hematoxylin and eosin (HE) staining and toluidine blue staining were used to analyze the number of bone marrow osteoblasts and adipocytes. RESULTS: Micro-CT results showed that compared with those in the young group, the bone mineral density (BMD) in the old group was significantly decreased, and the trabecular microstructure was seriously damaged. LLLI could significantly enhance the BMD and improve the damage to the trabecular microstructure; the three-point bending test revealed that LLLI could significantly improve the biomechanical properties and enhance the mechanical strength of the femur in the old group; the biochemical analysis showed that LLLI could significantly reduce Ca and P losses and elevate the levels of serum BAP and OCN; the bone histomorphology analysis results indicated that LLLI could increase BFR and mineral apposition rate (MAR), increase the number of osteoblasts and decrease the number of adipocytes in the bone marrow in the old group. CONCLUSIONS: LLLI can effectively improve osteoporosis, increase BMD, improve bone structure and improve bone biomechanical properties in old rats; at the same time, it increases the levels of serum BAP and OCN and the number of osteoblasts in the bone marrow, suggesting that the osteogenesis function of osteoblasts is enhanced.

Effect of in vivo low-level laser therapy on bone marrow-derived mesenchymal stem cells in ovariectomy-induced osteoporosis of rats.

Postmenopausal osteoporosis (PMOP) is considered by decreased bone strength that escalates the threat of fractures. Positive effects of photobiomodulation (PBM) with pulse wave have been demonstrated in cell culture and animal models. The aim of this study was to assess the in vivo effects of PBM on viability and calcium ion release of ovariectomy induced osteoporosis (OVX) - bone marrow derived mesenchymal stem cells (BMMSCs). MATERIAL AND METHODS: 18 female rats were distributed into the following groups: 1) control healthy, 2) LASER-healthy (890nm, 80Hz, 1.5J/cm2, three days weekly, 60days), 3) control OVX, 4) LASER-OVX, 5) Alendronate (Alen.)-OVX [0.5mg/kg, 5days per week, 60days], and 6) Alen.+LASER-OVX. Ovariectomy was done on rats of groups 3, 4, 5 and 6. After that all rats were euthanized and their MSC harvested and cultured in complete osteogenic medium. In all groups, BMMSC viability, and calcium colorimetric assay were performed. RESULTS: We observed a significant increase in optical density (OD) of BMMSCs viability in LASER healthy group compared to control-OVX, Alen.-OVX, LASER-OVX, LASER+Alen.-OVX, groups. LASER+Alen.-OVX group displayed a significant escalation in OD of BMMSCs viability compared to LASER-OVX, Alen.-OVX, and control-OVX groups. There were a significant increase in calcium ion release of LASER-healthy group compared to control healthy, control-OVX, Alen.-OVX, LASER-OVX, and LASER+Alen.-OVX groups. LASER+Alen.-OVX group displayed a significant escalation in calcium ion release compared to LASER-OVX, Alen.-OVX, and control-OVX groups. CONCLUSION: Pulse wave (PW) PBM significantly stimulated viability and cell proliferation of healthy BMMSCs compared to those of control-OVX, OVX-alendronate, OVX-LASER, and LASER+alendronate-OVX. In addition stimulatory effect of LASER+alendronate on viability and cell proliferation of OVX-BMMSCs compared to those of control-OVX, alendronate-OVX, and LASER-OVX groups were found.

Evaluation of the effects of photobiomodulation on vertebras in two rat models of experimental osteoporosis.

The aim of this study was to evaluate the effects of photobiomodulation (PBM) on cancellous bone in rat models of ovariectomized induced osteoporosis (OVX-D) and glucocorticoid-induced osteoporosis (GIOP). The experiment comprised of nine groups. A group of healthy rats was used for baseline evaluations. The OVX-D rats were further divided into groups as follows: control rats with osteoporosis, OVX-D rats that received alendronate (1 mg/kg 60 days), OVX-D rats treated with pulsed wave laser (890 nm, 80 Hz, 900 s, 0.0061 W/cm2, 5.5 J/cm2, three times a week, 60 days), and OVX-D rats treated with alendronate + pulsed laser. Dexamethasone was administered to the remaining rats that were split into four groups: control, alendronate-treated rats, laser-treated rats, and GIOP rats treated with alendronate + laser. T12, L1, L2, and L3 vertebrae were subjected to laser. Results of the current study demonstrated that OVX-D and GIOP significantly decreased some stereological parameters, and type 1 collagen gene expression compared to the healthy group. There was a significant increase in osteoclast number in both OVX-D and glucocorticoid administration compared to the healthy group. However, the detrimental effect of the OVX-D procedure on bone was more serious than glucocorticoid administration. Results showed that laser alone had a detrimental effect on trabecular bone volume, and cortical bone volume in groups GIOP and OVX-D compared to those in the healthy group. Alendronate significantly improved total vertebral bone volume, trabecular bone volume, and cortical bone volume, in GIOP and OVX-D groups compared to the laser-treated groups. Furthermore, the alendronate + laser in OVX-D rats and GIOP rats produced significantly increased osteoblast number and type 1 collagen gene expression and caused a significant decrease in osteoclast number compared to the controls.

Presenting a Method to Improve Bone Quality Through Stimulation of Osteoporotic Mesenchymal Stem Cells by Low-Level Laser Therapy.

OBJECTIVE: This review aims to present a method to improve bone quality through stimulation of osteoporotic mesenchymal stem cells (MSCs) by low-level laser therapy (LLLT). BACKGROUND: Osteoporosis (OP) is characterized by decreased bone mass and bone strength, which results in an increased incidence of bone fractures. These fractures often lead to additional disability and mortality. Osteoporotic MSCs have reduced osteogenic differentiation when cultured in their standard differentiation media. LLLT has a biostimulatory effect on fibroblasts and osteoblasts. MSCs have the ability to generate cells of connective tissue lineages, which includes the bones. Recently, transplantation of in vitro cultured bone marrow (BM) MSCs into sites at risk for development of osteoporotic bone has resulted in improved bone structure. METHODS: Comprehensive research was performed using PubMed, and biostimulatory effect of LLLT on bony cells and MSCs were studied. RESULTS: LLLT can stimulate growth, proliferation, and differentiation of SCs in vitro and in vivo. This ability of LLLT is an essential prerequisite for performing experiments related to disease control in humans. Thus, laser-treated osteoporotic autologous BMMSCs may represent a promising therapeutic method to protect the bones in patients with OP and prevent fractures in these patients. Therefore, researchers hypothesize that transplantation of in vitro laser-treated autologous cultured osteoporotic BMMSCs that have the appropriate osteogenic phenotype into sites at risk for development of osteoporotic bone may result in improved bone structure. In this respect, investigators have successfully used LLLT to restore autologous osteoporotic MSCs in vitro. Subsequently, these cells have been differentiated into osteoblast cell lines with the use of laser treatment after which they were transplanted into osteoporotic animal models. CONCLUSIONS: This technique might improve bone quality and structure. However, additional research must be undertaken to understand the underlying mechanisms of this treatment, validate its effectiveness, and assess the feasibility for clinical application of LLLT to treat MSCs in regeneration of osteoporotic bone.

Evaluation of the Effects of Photobiomodulation on Biomechanical Properties and Hounsfield Unit of Partial Osteotomy Healing in an Experimental Rat Model of Type I Diabetes and Osteoporosis.

BACKGROUND: Pulsed wave (PW) lasers exhibit biostimulatory effects on fractures in healthy and diabetic animals. OBJECTIVE: This study aims to assess the effects of photobiomodulation on bone strength and Hounsfield unit (HU) for repair of a bone defect in an experimental rat model of type I diabetes mellitus (TIDM) and osteoporosis (OP). METHODS: We divided 30 female rats into six groups of n = 5 per group: (1) ovariectomy (OVX) control, (2) OVX + PW laser and no TIDM, (3) OVX control + TIDM, (4) OVX + TIDM + PW laser, (5) OVX + TIDM + alendronate, and (6) OVX + TIDM + PW laser + alendronate. TIDM was induced in rats by streptozotocin (STZ). A partial osteotomy was made in the right tibia of each rat. We used an infrared laser (890 nm, 80 Hz, 1.5 J/cm2) 3 times per week. At 30 days after surgery, the callus areas within the rats' tibias were submitted to computed tomography scanning followed by the three-point bending test. RESULTS: The PW laser + alendronate group had significantly increased HU and biomechanical properties of repairing bone defect in STZ + OVX rats compared with the control groups. CONCLUSIONS: Combined treatment of PW laser and alendronate significantly enhanced bone repair in an experimental model rat of TIDM and OP.

Evaluation of the effects of pulsed wave LLLT on tibial diaphysis in two rat models of experimental osteoporosis, as examined by stereological and real-time PCR gene expression analyses.

Osteoporosis (OP) and osteoporotic fracture are major public health issues for society; the burden for the affected individual is also high. Previous studies have shown that pulsed wave low-level laser therapy (PW LLLT) has osteogenic effects. This study intended to evaluate the impacts of PW LLLT on the cortical bone of osteoporotic rats' tibias in two experimental models, ovariectomized and dexamethasone-treated. We divided the rats into four ovariectomized induced OP (OVX-d) and four dexamethasone-treated (glucocorticoid-induced OP, GIOP) groups. A healthy (H) group of rats was considered for baseline evaluations. At 14 weeks following ovariectomy, we subdivided the OVX-d rats into the following groups: (i) control which had OP, (ii) OVX-d rats treated with alendronate (1 mg/kg), (iii) OVX-d rats treated with LLLT, and (iv) OVX-d rats treated with alendronate and PW LLLT. The remaining rats received dexamethasone over a 5-week period and were also subdivided into four groups: (i) control rats treated with intramuscular (i.m.) injections of distilled water (vehicle), (ii) rats treated with subcutaneous alendronate injections (1 mg/kg), (iii) laser-treated rats, and (iv) rats simultaneously treated with laser and alendronate. The rats received alendronate for 30 days and underwent PW LLLT (890 nm, 80 Hz, 0.972 J/cm(2)) three times per week during 8 weeks. Then, the right tibias were extracted and underwent a stereological analysis of histological parameters and real-time polymerase chain reaction (RT-PCR). A significant increase in cortical bone volume (mm(3)) existed in all study groups compared to the healthy rats. There were significant decreases in trabecular bone volume (mm(3)) in all study groups compared to the group of healthy rats. The control rats with OP and rats from the vehicle group showed significantly increased osteoclast numbers compared to most other groups. Alendronate significantly decreased osteoclast numbers in osteoporotic rats. Concurrent treatments (compounded by PW LLLT and alendronate) produce the same effect on osteoporotic bone.

An evaluation of the effect of pulsed wave low-level laser therapy on the biomechanical properties of the vertebral body in two experimental osteoporosis rat models.

Osteoporosis (OP) increases vertebral fragility as a result of the biomechanical effects of diminished bone structure and composition. This study has aimed to assess the effects of pulsed wave low-level laser therapy (PW LLLT) on cancellous bone strength of an ovariectomized (OVX-d) experimental rat model and a glucocorticoid-induced OP (GIOP) experimental rat model. There were four OVX-d groups and four dexamethasone-treated groups. A group of healthy rats was used for baseline evaluations. The OVX-d rats were further subdivided into the following groups: control rats with OP, OVX-d rats that received alendronate, OVX-d rats treated with PW LLLT, and OVX-d rats treated with alendronate and PW LLLT. The remaining rats received dexamethasone and were divided into four groups: control, alendronate-treated rats, laser-treated rats, and laser-treated rats with concomitant administration of alendronate. PW LLLT (890 nm, 80 Hz, 0.972 J/cm(2)) was performed on the spinal processes of the T12, L1, L2, and L3 vertebras. We extracted the L1 vertebrae and submitted them to a mechanical compression test. Biomechanical test findings showed positive effects of the PW LLLT and alendronate administration on increasing bending stiffness and maximum force of the osteoporotic bones compared to the healthy group. However, laser treatment of OVA-d rats significantly increased stress high load compared to OVA-d control rats. PW LLLT preserved the cancellous (trabecular) bone of vertebra against the detrimental effects of OV-induced OP on bone strength in rats compared to control OV rats.

Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model.

Low-level laser therapy (LLLT) benefits bone metabolism, but its use needs to be standardized. We evaluated the effects of LLLT on bone defects in calvaria of ovariectomized rats. Stereology was used to calculate tissue repair volume (V tr ), density of trabecular bone volume (Vv t ), total volume of newly formed trabecular bone (Vtot), and the area occupied by collagen fibers (A C ). Fifty-four Wistar rats were submitted to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups (n = 6), and 24 h after defects, the treatment started with a 780-nm low-intensity GaAlAs laser: G1, G2, and G3 received 3 sessions of 0, 20, and 30 J/cm(2) respectively; G4, G5, and G6 received 6 sessions of 0, 20, and 30 J/cm(2), respectively; and G7, G8, and G9 received 12 sessions of 0, 20, and 30 J/cm(2), respectively. A normal distribution was found for all of the data. The test used to verify the normality was the Kolmogorov-Smirnov (KS, p > 0.05). The one-way ANOVA followed by Tukey's post hoc test was used for data processing. A difference of p < 0.05 was considered statistically significant. Groups G2 and G1 showed significance for V tr , Vv t , Vtot, and (A C ). Results were significant for (Vv t ) and (Vtot) between G3 and G1. There were no significant results between G5 and G4 as well as between G8 and G7. Groups G6 and G4 results showed statistical difference for V tr , Vv t , Vtot, and (A C ). Groups G9 and G7 showed significance for V tr , Vv t , Vtot, and (A C ). In conclusion, there was new bone formation in the groups that received 20 and 30 J/cm(2) when compared to control groups, but over time, the dose of 30 J/cm(2) showed better stereological parameters when compared to 20 J/cm(2).

Evaluation of the effects of LLLT on biomechanical properties of tibial diaphysis in two rat models of experimental osteoporosis by a three point bending test.

Osteoporosis (OP) is a disease which causes bone loss and fractures, leading to severe pain and deformity. This study has aimed to assess the effects of pulsed wave low-level laser therapy (PW LLLT) on cortical bone in two experimental models of OP in rats. There were four ovariectomized (OVX-d) groups and four dexamethasone-treated groups. The healthy group were considered for baseline evaluations. At 14 weeks following ovariectomy, the OVX-d rats were further subdivided into the following: control rats with OP, OVX-d rats that received alendronate (1 mg/kg), OVX-d rats treated with LLLT, and OVX-d rats treated with alendronate and LLLT. The remaining rats received dexamethasone for 5 weeks and were divided into four groups: control, alendronate-treated rats (1 mg/kg), laser-treated rats, and laser-treated rats with concomitant administration of alendronate. The rats received alendronate for 30 days. LLLT (890 nm, 80 Hz, 0.972 J/cm(2)) was performed on the tibias three times per week for 8 weeks. After 8 weeks, tibias were extracted and submitted to a three-point bending test. PW LLLT did not increase the biomechanical parameters of osteoporotic bones compared to controls and healthy rats. PW LLLT associated with alendronate treatment significantly increased stress high load in OVX-d rats compared to the healthy group. PW LLLT at the current study parameters failed to cause beneficial biomechanical effects in the examined osteoporotic cortical bones. PW LLLT associated with alendronate treatment produced a more remarkable effect on bone strength in the ovariectomized induced OP rat model.

Radon balneotherapy and physical activity for osteoporosis prevention: a randomized, placebo-controlled intervention study.

Low-dose radon hyperthermia balneo treatment (LDRnHBT) is applied as a traditional measure in the non-pharmacological treatment of rheumatic diseases in Europe. During the last decades, the main approach of LDRnHBT was focused on the treatment of musculoskeletal disorders, but scientific evidence for the biological background of LDRnHBT is weak. Recently, evidence emerged that LDRnHBT influences bone metabolism. We investigated, whether combined LDRnHBT and exercise treatment has an impact on bone metabolism and quality of life in a study population in an age group at risk for developing osteoporosis. This randomized, double-blind, placebo-controlled trial comprised guided hiking tours and hyperthermia treatment in either radon thermal water (LDRnHBT) or radon-free thermal water (PlaceboHBT). Markers of bone metabolism, quality of life and somatic complaints were evaluated. Statistics was performed by linear regression and a linear mixed model analysis. Significant changes over time were observed for most analytes investigated as well as an improvement in self-assessed health in both groups. No significant impact from the LDRnHBT could be observed. After 6 months, the LDRnHBT group showed a slightly stronger reduction of the osteoclast stimulating protein receptor activator of nuclear kB-ligand compared to the PlaceboHBT group, indicating a possible trend. A combined hyperthermia balneo and exercise treatment has significant immediate and long-term effects on regulators of bone metabolism as well as somatic complaints. LDRnHBT and placeboHBT yielded statistically equal outcomes.

Low-level laser therapy using the minimally invasive laser needle system on osteoporotic bone in ovariectomized mice.

This study tested the effectiveness of low-level laser therapy (LLLT) in preventing and/or treating osteoporotic trabecular bone. Mice were ovariectomized (OVX) to induce osteoporotic bone loss. The tibiae of eight OVX mice were treated for 5 days each week for 2 weeks by LLLT (660 nm, 3 J) using a minimally invasive laser needle system (MILNS) which is designed to minimize loss of laser energy before reaching bone (LASER group). Another eight mice received a sham treatment (SHAM group). Structural parameters of trabecular bone were measured with in vivo micro-computed tomography images before and after laser treatment. After LLLT for 2 weeks, the percentage reduction (%R) was significantly lower in BV/TV (bone volume fraction) and Tb.N (trabecular number, p<0.05 and p<0.05) and significant higher in Tb.Sp (trabecular separation) and SMI (structure model index, p<0.05 and p<0.05) than in the SHAM group. The %R in BV/TV at sites directly treated by LLLT was significantly lower in the LASER group than the SHAM group (p<0.05, p<0.05). These results indicated that LLLT using MILNS may be effective for preventing and/or treating trabecular bone loss and the effect may be site-dependent in the same bone.

Systemic treatment with pulsed electromagnetic fields do not affect bone microarchitecture in osteoporotic rats.

PURPOSE: Pulsed electromagnetic fields (PEMF) are currently used in the treatment of spinal fusions and non-unions. There are indications that PEMF might also be effective in the treatment of osteoporosis. In this study we examined whether whole-body PEMF treatment affects the bone microarchitecture in an osteoporotic rat model. METHODS: Twenty-week-old female rats were ovariectomised (n=20). Four different PEMF treatment protocols based on previous experimental studies and based on clinically used PEMF signals were examined (2 h/day, 5 days/week). A control group did not receive PEMF. At zero, three and six weeks cancellous and cortical bone architectural changes at the proximal tibia were evaluated using in vivo microCT scanning. RESULTS: PEMF treatment did not induce any changes in cancellous or cortical bone compared to untreated controls. CONCLUSIONS: Although previous studies have shown strong effects of PEMF in osteoporosis we were unable to demonstrate this in any of the treatment protocols. Using in vivo microCT scanning we were able to identify small bone changes in time. Subtle differences in the experimental set-up might explain the differences in study outcomes in the literature. Since PEMF treatment is safe, future experimental studies on the effect of PEMF on bone can better be performed directly on humans, eliminating the potential translation issues between animals and humans. In this study we found no support for the use of PEMF in the treatment of osteoporosis.

Development of a minimally invasive laser needle system: effects on cortical bone of osteoporotic mice.

Many studies have shown the positive effects of low-level laser therapy in the treatment of bone disease. However, laser radiation is scattered in the skin surface which reduces the initial photon density for tissue penetration and consequently the therapeutic efficacy. We developed a minimally invasive laser needle system (MILNS) to avoid laser scattering in tissue and investigated its stimulatory effects in the cortical bone of osteoporotic mice. The MILNS was designed to stimulate cortical bone directly by employing fine hollow needles to guide 100 µm optical fibers. The study animals comprised 12 mice which were subjected to sciatic denervation of the right hind limb and were randomly divided into two groups, a sham group and a laser group which were treated using the MILNS for 2 weeks without and with laser irradiation, respectively. In vivo micro-CT images were taken to analyze the structural parameters and bone mineral density. After 2 weeks of treatment with the MILNS, the relative changes in mean polar moment inertia, cross-section thickness, and periosteal perimeter were significantly higher in the laser group than in the sham group. Moreover, the distribution of bone mineral density index was higher in the laser group. The MILNS was developed as a minimally invasive treatment modality for bone disease and resulted in positive therapeutic efficacy in the cortical bone of osteoporotic mice.

[Certain changes in mineral metabolism of patients with osteoarthrosis and osteoporosis under the influence of combined treatment].

Disturbances of calcium and phosphorus metabolism in patients with articular disorders are gender-dependent and related to the presence of osteoporosis. Concomitant abnormalities in collagen synthesis are more pronounced in women than in men and especially in patients with osteoporosis, in agreement with their altered hormonal status. Combined balneo-physiotherapeutic treatment including mid-wavelength ultraviolet irradiation partially normalizes calcium and phosphorus metabolism but fails to significantly decrease the enhanced activity of alkaline phospatase and elevated blood oxyproline level that collectively account for the low regenerative potential of osteoblasts.

Low level laser can be a novel adjuvant method for orthodontic tooth movement on postmenopausal women.

Osteoporosis, a pathological state commonly saw on postmenopausal women, has shown to affect jaw bone and the periodontium. While more and more adult patients seeking orthodontic treatment for a beautiful smile, the current strategy has not work well for extraction space closure in postmenopausal women with osteoporosis and concurrent bisphosphates taken. A new and non-invasive method is hoped to make a beginning. There are ample evidences showing low level laser has favorable effects on pain relief and wound healing procedure of hard and soft tissue. These effects are due to its ability to stimulate cell metabolism, angiogenesis, bone formation and osteoclastogenesis. The hypothesis we proposed herein is that low level laser may be a valuable adjuvant method for protecting and facilitating orthodontic tooth movement on this kind of patients.

Evaluation of the osteogenic effect of low-level laser therapy (808 nm and 660 nm) on bone defects induced in the femurs of female rats submitted to ovariectomy.

The present study aimed to evaluate the effects of LLLT (660- and 808-nm wavelengths) on the process of repairing bone defects induced in the femurs of female rats submitted to ovariectomy. Bilateral ovariectomies were performed on 18 female Wistar rats, which were divided into control and irradiated groups after the digital analysis of bone density showed decreased bone mass and after standardized drilling of the femurs. The irradiated groups received 133 J/cm(2) of AsGaAl (660-nm) and InGaAlP (880-nm) laser radiation. The animals were euthanized on days 14 and 21 after the bone defects were established. Detailed descriptive histological evaluations were performed, followed by semi-quantitative histomorphometry. The results from days 14 and 21 showed that the irradiated groups presented increased density of osteoblasts, fibroblasts, and immature osteocytes on the tissue surface compared with the control (non-irradiated) groups (p < 0.05). Additionally, inflammatory infiltrate evaluations showed that LLLT decreased the accumulation of leukocytes when compared to the control treatment (p < 0.05). We concluded that, in our experimental model, both wavelengths (660-nm and 880-nm) inhibited the inflammatory process and induced the proliferation of cells responsible for bone remodeling and repair.

Biosilicate® and low-level laser therapy improve bone repair in osteoporotic rats.

The aim of this study was to investigate the effects of a novel bioactive material (Biosilicate®) and low-level laser therapy (LLLT) on bone fracture consolidation in osteoporotic rats. Forty female Wistar rats were submitted to ovariectomy (OVX) to induce osteopenia. Eight weeks after surgery, the animals were randomly divided into four groups of 10 animals each: a bone defect control group (CG); a bone defect filled with Biosilicate group (BG); a bone defect filled with Biosilicate and irradiated with LLLT at 60 J/cm(2) group (BG60); and a bone defect filled with Biosilicate and irradiated with LLLT at 120 J/cm(2) group (BG120). Bone defects were surgically performed on both tibias. The size of particle used for Biosilicate was 180-212 µm. Histopathological analysis showed that bone defects were predominantly filled with the biomaterial in specimens treated with Biosilicate. LLLT with either 60 or 120 J/cm(2) was able to increase collagen, Cbfa-1, VGEF and COX-2 expression in the circumjacent cells of the biomaterial. A morphometric analysis revealed that the Biosilicate + laser groups showed a higher amount of newly formed bone. Our results indicate that laser therapy improves bone repair process in contact with Biosilicate as a result of increasing bone formation, as well as COX-2 and Cbfa-1 immunoexpression, angiogenesis and collagen deposition in osteoporotic rats.