Bone regeneration by low-level laser therapy and low-intensity pulsed ultrasound therapy in the rabbit calvarium

Efficacy of photobiomodulation using diode laser 650 nm combined with nano-cellulose and nano-amorphous calcium phosphate in bone healing of rabbit tibial defects assessed by H&E staining and computed tomography

BACKGROUND

The purpose of the current study was to evaluate the effect of Diode LLLT 650 nm, TEMPO oxidized Nano-fibrillated cellulose mixed with Nano-Amorphous calcium phosphate, and their combination on bone healing in rabbit tibia using H&E staining and computed tomography.

METHODS

Eighteen adult male New Zealand rabbits were selected, two circular bone defects were created in each tibia, resulting in four bony defects in each rabbit, representing the four tested groups; group A (negative control), group B (filled with mineralized nano-cellulose), group C (combination), group D (laser). Animals were euthanized after two weeks and one month, defects were assessed by CT for bone density, then histological samples were examined by H&E stain.

RESULTS

In both evaluation periods, group D recorded the greatest mean area percent of new bone formation and bone density, followed by group A, while group C recorded the lowest value. Groups A and D showed full closure of the defects, while groups B and C showed partial defect closure with retained bone graft material. H&E and CT showed that Laser group had the best results of defects healing, bone density and new bone formation, followed by the negative control group.

CONCLUSIONS

Diode laser 650nm photobiomodulation significantly improved bone defects healing. Mineralized nano-cellulose experimental bone substitute material showed a delayed effect in bone healing and graft material resorption. The combination of LLLT with the graft material had no positive outcome on bone defect healing.

Photobiomodulation therapy's impact on angiogenesis and osteogenesis in orthodontic tooth movement: in vitro and in vivo study

BACKGROUND

This study explores the effectiveness of Photobiomodulation Therapy (PBMT) in enhancing orthodontic tooth movement (OTM), osteogenesis, and angiogenesis through a comprehensive series of in vitro and in vivo investigations. The in vitro experiments involved co-culturing MC3T3-E1 and HUVEC cells to assess PBMT's impact on cell proliferation, osteogenesis, angiogenesis, and associated gene expression. Simultaneously, an in vivo experiment utilized an OTM rat model subjected to laser irradiation at specific energy densities.

METHODS

In vitro experiments involved co-culturing MC3T3-E1 and HUVEC cells treated with PBMT, enabling a comprehensive assessment of cell proliferation, osteogenesis, angiogenesis, and gene expression. In vivo, an OTM rat model was subjected to laser irradiation at specified energy densities. Statistical analyses were performed to evaluate the significance of observed differences.

RESULTS

The results revealed a significant increase in blood vessel formation and new bone generation within the PBMT-treated group compared to the control group. In vitro, PBMT demonstrated positive effects on cell proliferation, osteogenesis, angiogenesis, and gene expression in the co-culture model. In vivo, laser irradiation at specific energy densities significantly enhanced OTM, angiogenesis, and osteogenesis.

CONCLUSIONS

This study highlights the substantial potential of PBMT in improving post-orthodontic bone quality. The observed enhancements in angiogenesis and osteogenesis suggest a pivotal role for PBMT in optimizing treatment outcomes in orthodontic practices. The findings position PBMT as a promising therapeutic intervention that could be seamlessly integrated into orthodontic protocols, offering a novel dimension to enhance overall treatment efficacy. Beyond the laboratory, these results suggest practical significance for PBMT in clinical scenarios, emphasizing its potential to contribute to the advancement of orthodontic treatments. Further exploration of PBMT in orthodontic practices is warranted to unlock its full therapeutic potential.

Evaluation of the regenerative capacity of stem cells combined with bone graft material and collagen matrix using a rabbit calvarial defect model

PURPOSE

The purpose of this study was to evaluate the regenerative capacity of stem cells combined with bone graft material and a collagen matrix in rabbit calvarial defect models according to the type and form of the scaffolds, which included type I collagen matrix and synthetic bone.

METHODS

Mesenchymal stem cells (MSCs) were obtained from the periosteum of participants. Four symmetrical 6-mm-diameter circular defects were made in New Zealand white rabbits using a trephine drill. The defects were grafted with (1) group 1: synthetic bone (β-tricalcium phosphate/hydroxyapatite [β-TCP/HA]) and 1×105 MSCs; (2) group 2: collagen matrix and 1×105 MSCs; (3) group 3: β-TCP/HA, collagen matrix covering β-TCP/HA, and 1×105 MSCs; or (4) group 4: β-TCP/HA, chipped collagen matrix mixed with β-TCP/HA, and 1×105 MSCs. Cellular viability and cell migration rates were analyzed.

RESULTS

Uneventful healing was achieved in all areas where the defects were made at 4 weeks, and no signs of infection were identified during the healing period or at the time of retrieval. New bone formation was more evident in groups 3 and 4 than in the other groups. A densitometric analysis of the calvarium at 8 weeks post-surgery showed the highest values in group 3.

CONCLUSIONS

This study showed that the highest regeneration was found when the stem cells were applied to synthetic bone along with a collagen matrix.

Effect of Ultrasound Therapy on Expression of Vascular Endothelial Growth Factor, Vascular Endothelial Growth Factor Receptors, CD31 and Functional Recovery After Facial Nerve Injury

Functional recovery is provided by some neurotrophic factors released from the near vicinity of the injury site. Ultrasound treatment is known to increase neurotrophic factor expression. This study was aimed at determining the effect of ultrasound treatment on the expression of vascular endothelial growth factor (VEGF), its receptors and new vessel formation after facial nerve injury. Sixty-four Wistar rats were divided into four groups: control (group 1), sham (group 2), facial-facial coaptation (group 3), and facial-facial coaptation and ultrasound treatment (group 4). Animals in each group were evaluated on the 14th and 28th days. Immunohistochemical staining and electrophysiological and gene-level evaluations were performed for the expression of VEGF and its receptors. When the results were evaluated, it was determined that VEGF, VEGFR1 (VEGF receptor 1), VEGFR2 (VEGF receptor 2) and CD31 levels were significantly higher in groups 3 and 4 compared with the control and sham groups. The increase in these values was more prominent after 28 d of ultrasound treatment than all groups. Electrophysiological results revealed similar evident functional improvement in group 4 with decreased latency and increased amplitudes compared with group 3. Our findings suggest that ultrasound treatment might promote injured facial nerve regeneration by stimulating release of VEGF and its receptors and may result in functional improvement.

A novel ultrasound-mediated nanodroplet-based gene delivery system for osteoporosis treatment

This project aimed to develop, optimize, and test an ultrasound-responsive targeted nanodroplet system for the delivery of osteoporosis-related silencing gene Cathepsin K small interfering RNA (CTSK siRNA) for osteoporosis treatment. The nanodroplet (ND) is composed of a gas core made from perfluorocarbon, stabilized with albumin, encapsulated with CTSK siRNA, and embedded with alendronate (AL) for bone targeting (CTSK siRNA-ND-AL). Following the development, the responsiveness of CTSK siRNA-ND-AL to a therapeutic ultrasound probe was examined. The results of biocompatibility tests with human bone marrow-derived mesenchymal stem cells proved no significant cell death (P > 0.05). When the CTSK siRNA-ND-AL was supplemented with human osteoclast precursors, they suppressed osteoclastogenesis. Thus, this project establishes the potential of nanotechnology and ultrasound to deliver genes into the osteoclasts. This research also presents a novel ultrasound responsive and targeted nanodroplet platform that can be used as a gene and drug delivery system for various diseases including cancer.

Optimal Parameters of Laser Therapy to Improve Critical Calvarial Defects

Body bones play diverse pivotal roles, including the protection of vital organs. For instance, the integrative functions of the brain controlling diverse peripheral actions can be affected by a traumatic injury on the calvaria and the reparative process of a large defect is a challenge in the integrative physiology. Therefore, the development of biomaterials and approaches to improve such defects still requires substantial advances. In this regard, the most attractive approaches have been covering the cavity with inorganic bovine bone (IBB) and, more recently, also using low-level laser therapy (LT), but this issue has opened many questions. Here, it was determined the number of LT sessions required to speed up and to intensify the recovery process of two 5-mm-diameter defects promoted in the calvaria of each subgroup of six adult Wistar rats. The quantitative data showed that 30 days post-surgery, the recovery process by using blood clot-filling was not significantly influenced by the number of LT sessions. However, in the IBB-filled defects, the number of LT sessions markedly contributed to the improvement of the reparative process. Compared to the Control group (non-irradiated), the percentage of mineralization (formation of new bone into the cavities) gradually increased 25, 49, and 52% with, respectively, 4, 7, and 11 sessions of LT. In summary, combining the use of IBB with seven sessions of LT seems to be an optimal approach to greatly improve the recovery of calvarial defects. This translational research opens new avenues targeting better conditions of life for those suffering from large bone traumas and in the present field could contribute to preserve the integrative functions of the brain.

Effect of low-intensity pulsed ultrasound on orofacial sensory disturbance following inferior alveolar nerve injury: Role of neurotrophin-3 signaling

Percutaneous treatment of low-intensity pulsed ultrasound (LIPUS) to the site of inferior alveolar nerve (IAN) transection promotes functional regeneration, but the detailed mechanism is unknown. We examined the involvement of neurotrophin-3 (NT-3), which primarily binds with tropomyosin receptor kinase C (TrkC), in functional transected IAN regeneration following LIPUS treatment in rats. Daily LIPUS treatment to the transected IAN was performed, and the mechanical sensitivity of the facial skin was measured for 14 d. On day 5 after IAN transection, the expression of NT-3 in the transected IAN and TrkC-positive trigeminal ganglion neurons were immunohistochemically examined. Further, the effect of TrkC neutralization on the acceleration of facial mechanosensory disturbance restoration due to LIPUS treatment was analyzed. LIPUS treatment to the site of IAN transection significantly facilitated functional recovery from sensory disturbance on facial skin. Schwann cells in the transected IAN expressed NT-3, and LIPUS treatment increased the amount of NT-3. The facilitated recovery from the mechanosensory disturbance by continuous LIPUS treatment was inhibited by the ongoing TrkC neutralization at the IAN transection site. These results suggest that LIPUS treatment accelerates the recovery of orofacial mechanosensory function following IAN transection through the enhancement of NT-3 signaling in the transected IAN.

Analysis on Efficacy of Chitosan-Based Gel on Bone Quality and Quantity

Objectives: To assess and compare the quantity and the quality of the newly bone generated when using chitosan-based gel scaffold and osteoprotegerin-chitosan gel scaffold.

Methods: A total of 18 critical-sized defects on New Zealand white rabbit craniums were created. In 12 defects, either chitosan gel or osteoprotegerin-chitosan gel was implanted the last six defects were kept unfilled as a control. Bone formation was examined at 6 and 12 weeks. Bone’s specimens were scanned using the High-resolution peripheral quantitative computed tomography. Histological and histomorphometric analysis were carried out to compare the volume and area of regenerated bone.

Results: The results of the HR-pQCT showed that bone volume and densities in the osteoprotegerin-chitosan gel group were significantly higher than the chitosan gel and control groups whereas, the bone volume density in the chitosan gel group was significantly higher than the control group in both intervals time (p = 0.01, p = 000). No significant difference in bone volume between the chitosan gel and control groups (p = 0.506, p = 0.640) was observed. However, similar findings were shown in the histomorphometric analysis, with the highest new bone formation was observed in the OPG-chitosan gel group followed by the chitosan group. The mean percentage of new bone was greater at 12 weeks compared to 6 weeks in all groups.

Conclusions: Chitosan-based gel demonstrated a significant bone quantity and quality compared to unfilled surgical defects. Consistently, osteoprotegerin enhanced the chitosan gel in bone regeneration.

Review of physical stimulation techniques for assisting distraction osteogenesis in maxillofacial reconstruction applications

Distraction Osteogenesis (DO) is an emerging limb lengthening method for the reconstruction of the hard tissue and the surrounding soft tissue, in different human body zones. DO plays an important role in treating bone defects in Maxillofacial Reconstruction Applications (MRA) due to reduced side effects and better formed bone tissue compared to conventional reconstruction methods i.e. autologous bone graft, and alloplast implantation. Recently, varying techniques have been evaluated to enhance the characteristics of the newly formed tissues and process parameters. Promising results have been shown in assisting DO treatments while benefiting bone formation mechanisms by using physical stimulation techniques, including photonic, electromagnetic, electrical, and mechanical stimulation technique. Using assisted DO techniques has provided superior results in the outcome of the DO procedure compared to a standard DO procedure. However, DO methods, as well as assisting technologies applied during the DO procedure, are still emerging. Studies and experiments on developed solutions related to this field have been limited to animal and clinical trials. In this review paper, recent advances in physical stimulation techniques and their effects on the outcome of the DO treatment in MRA are surveyed. By studying the effects of using assisting techniques during the DO treatment, enabling an ideal assisted DO technique in MRA can be possible. Although mentioned techniques have shown constructive effects during the DO procedure, there is still a need for more research and investigation to be done to fully understand the effects of assisting techniques and advanced technologies for use in an ultimate DO procedure in MRA.

Interaction between Laser Light and Osteoblasts: Photobiomodulation as a Trend in the Management of Socket Bone Preservation-A Review

Simple Summary

Dental implants are becoming an accepted tool, and thousands of implants are placed every year by specialists and general practitioners. However, more than 10% of bone surgeries and related procedures can show healing complications as a consequence of infections, tissue damage, or inadequate blood supply. In particular, a deficient blood supply impacts on the optimal healing process because of altered oxygen delivery to cells in the wound and a decrease in their energy supply. Researchers showed how red and infrared light affects key cellular pathways by interacting with specific photoacceptors located within the cell, particularly in mitochondria. Low-level laser therapy or photobiomodulation (PBM), as the recent medical subject heading defines it, is based on a light–cell interaction, which modifies cell metabolism by increasing oxygen consumption and ATP production through mitochondria. Although not all aspects of this interconnection are completely described, many in vitro and in vivo studies showed the benefit of PBM in wound defect management. For instance, treatment of bone with PBM results in a greater amount of new-formed osteoblasts and matrix, an increase in collagen synthesis, and microvascular reestablishment. In our review, we highlight the osteoblast–light interaction, and the in vivo therapeutic tool of PBM for socket preservation is discussed.

Abstract

Bone defects are the main reason for aesthetic and functional disability, which negatively affect patient’s quality of life. Particularly, after tooth extraction, the bone of the alveolar process resorbs, limiting the optimal prosthetic implant placement. One of the major pathophysiological events in slowly- or non-healing tissues is a blood supply deficiency, followed by a significant decrease in cellular energy amount. The literature shows that photons at the red and infrared wavelengths can interact with specific photoacceptors located within the cell. Through this mechanism, photobiomodulation (PBM) can modify cellular metabolism, by increasing mitochondrial ATP production. Here, we present a review of the literature on the effect of PBM on bone healing, for the management of socket preservation. A search strategy was developed in line with the PRISMA statement. The PubMed and Scholar electronic databases were consulted to search for in vivo studies, with restrictions on the year (<50 years-old), language (English), bone socket preservation, and PBM. Following the search strategy, we identified 269 records, which became 14, after duplicates were removed and titles, abstract and inclusion-, exclusion-criteria were screened. Additional articles identified were 3. Therefore, 17 articles were included in the synthesis. We highlight the osteoblast–light interaction, and the in vivo therapeutic tool of PBM is discussed.

Systemic Effects of Photobiomodulation on the Morphology of the Thyroid and Sublingual Glands: A Study in Rabbits

Objective: To investigate whether photobiomodulation (PBM) applied in a clinical situation with the purpose of improving the healing process of implants placed in the rabbit mandible would cause any morphological change in the thyroid and sublingual glands as a systemic effect of laser irradiation. Methods: Thirty-two New Zealand rabbits were randomly divided into four groups of eight animals each, one control group (CI, nonirradiated animals) and three experimental groups (EI, EII, and EIII) that received PBM postoperatively with an aluminum/gallium/arsenide laser diode (Theralase^®) at a wavelength of 830 nm (infrared) and 50 mW output power applied to two irradiation fields per session, for a total of seven sessions. All rabbits underwent surgical extraction of the mandibular left incisor, followed by immediate placement of an osseointegrated implant in the fresh socket. The experimental groups EI, EII, and EIII received PBM at an energy density of 5, 2.5, and 10 J/cm², respectively, per irradiation field. Results: There was no histomorphometric change in any of the groups. Conclusions: PBM, based on the irradiation protocol used in this study, does not cause morphological changes in the thyroid and sublingual glands when used to stimulate peri-implant bone healing in the rabbit mandible.

Effect of laser treatment on outcomes of tooth replantation - A systematic review

Objectives

Over the last few years, several studies have investigated the effect of laser treatment on the replantation of avulsed teeth. We conducted this study to systematically analyse and assess the outcomes and quality of these studies.

Methods

Using the keywords ‘laser’, ‘tooth’, and ‘replantation’, two investigators conducted an electronic search of the PubMed, MEDLINE, Embase, ISI Web of Knowledge and Google Scholar databases. Any studies not meeting the inclusion criteria were excluded. The focused question was ‘Does laser treatment influence the outcomes of tooth replantation?’

Results

Nine studies were included and assessed in this review. In the majority of the selected studies, laser treatment had a positive outcome on preventing root resorption and in promoting periodontal regeneration. However, only three studies were given a quality score of ‘medium’, while six were marked as ‘low’.

Conclusion

Laser irradiation may reduce root resorption and favour periodontal regeneration following replantation of the avulsed tooth. However, more well-designed long-term animal and human studies are needed before lasers can be used clinically to improve the outcomes for replanted teeth.

Effect of Low- Level Laser Therapy on Bone Regeneration of Critical-Size Bone Defects: A Systematic Review of In Vivo Studies and Meta-Analysis

OBJECTIVE

Low-level laser therapy is a method for osteogenesis since it stimulates cell proliferation, vascularization and osteoblastic activity. Various protocols applying low-level laser with different outcomes exist. The aim of the present study was to review the result of different methods on bone formation in critical-size defects of in vivo studies.

DESIGN

According to PRISMA statement, electronic search of PubMed, google scholar, Scopus and Web of Science and a hand search limited to in vivo English language studies until December 2019. Studies used low-level laser therapy in bone regeneration of critical-size defects met the inclusion criteria and which used high power lasers or a defect size smaller than 5 mm, were excluded.

RESULTS

Finally, 18 studies were included. Fourteen studies utilized low-level laser with a wavelength ranging from 606 to 980 nm and 53 % of studies applied low-level laser in a single session. Ten studies utilized continuous wave mode of laser. Highest and lowest values of power density were 1.5 W/cm² and 0.1 W/cm² in order. Eleven studies evaluated low-lever laser therapy on defects of 5 mm in calvaria. Meta-analysis showed the positive effect of low-level laser therapy on osteogenesis after 30 days compared to control group and no significant difference after 60 days.

CONCLUSIONS

New bone formation can be increased in early stage by applying low-level laser therapy through stimulating osteoblasts and fibroblasts' proliferation. This effect would be more remarkable by combining with bone substitutes. Hence, for each case, protocol selection should be performed according defect's properties, attentively.

Photobiomodulation therapy (PBMT) in bone repair: A systematic review

BACKGROUND

Photobiomodulation therapy (PBMT) using low-level laser influences the release of several growth factors involved in the formation of epithelial cells, fibroblasts, collagen and vascular proliferation, besides accelerating the synthesis of bone matrix due to the increased vascularization and lower inflammatory response, with significant increase of osteocytes in the irradiated bone. Considering its properties, beneficial effects and clinical relevance, the aim of this review was to analyze the scientific literature regarding the use of PBMT in the process of bone defect repair.

METHODS

Electronic search was carried out in PubMed/MEDLINE^Ⓡ and Web of Science databases with combination of the descriptors low-level laser therapy AND bone repair, considering the period of publication until the year 2018.

RESULTS

The literature search identified 254 references in PubMed/MEDLINE and 204 in Web of Science, of which 33 and 4 were selected, respectively, in accordance with the eligibility requirements. The analysis of researches showed articles using PBMT in several places of experimentation in the subjects, different types of associated biomaterials, stimulatory effects on cell proliferation, besides variations in the parameters of use of laser therapy, mainly in relation to the wavelength and density of energy. Only four articles reported that the laser did not improve the osteogenic properties of a biomaterial.

CONCLUSIONS

Many studies have shown that PBMT has positive photobiostimulatory effects on bone regeneration, accelerating its process regardless of parameters and the use of biomaterials. However, standardization of its use is still imperfect and should be better studied to allow correct application concerning the utilization protocols.

Anaesthetic and Perioperative Management of 14 Male New Zealand White Rabbits for Calvarial Bone Surgery

Simple Summary

Bone substitutes are commonly used when bone grafts are necessary in human craniofacial surgery. To study the properties and biologic behaviour of those substitutes, they can be implanted in experimental animals. A frequently used model involves the creation of critical-sized defects (defects that are too large to heal by themselves) in the rabbits calvaria (the top part of the skull). The procedure was initially described in 1989 and the authors considered and reported that post-operative analgesia was not necessary. In our experience, this procedure is invasive and can result in severe postoperative pain. The anaesthetic management of rabbits undergoing this procedure is challenging. Most of the recent publications using this model fail to provide sufficient information on perioperative animal management. With this report we have aimed to document a possible practical and simple anaesthetic and postoperative management of rabbits undergoing this procedure. Particular emphasis has been placed on postoperative pain assessment, duration and treatment.

Abstract

Calvarial bone surgery on rabbits is frequently performed. This report aims to document a simple and practical anaesthetic and perioperative management for this procedure. Fourteen male New Zealand white rabbits were included in the study. Subcutaneous (SC) dexmedetomidine, ketamine and buprenorphine ± isoflurane vaporized in oxygen administered through a supraglottic airway device (V-gel^®) provided clinically suitable anaesthesia. Supplemental oxygen was administered throughout recovery. Monitoring was clinical and instrumental (pulse-oximetry, capnography, invasive blood pressure, temperature, arterial blood gas analysis). Lidocaine was infiltrated at the surgical site and meloxicam was injected subcutaneously as perioperative analgesia. After surgery, pain was assessed five times daily (composite behavioural pain scale and grimace scale). Postoperative analgesia included SC meloxicam once daily for four days and buprenorphine every 8 h for three days (unless both pain scores were at the lowest possible levels). Rescue analgesia (buprenorphine) was administered in case of the score > 3/8 in the composite pain scale, >4/10 on the grimace scale or if determined necessary by the caregivers. Airway management with a V-gel^® was possible but resulted in respiratory obstruction during the surgery in two cases. Hypoventilation was observed in all rabbits. All rabbits experienced pain after the procedure. Monitoring, pain assessments and administration of postoperative analgesia were recommended for 48 h.

Inhibition of myostatin signal pathway may be involved in low-intensity pulsed ultrasound promoting bone healing

PURPOSE

Low-intensity pulsed ultrasound (LIPUS) is effective in promoting bone healing, and a myostatin deficiency also has a positive effect on bone formation. In this study, we evaluated the effects of LIPUS on bone healing in rats in vivo and investigated the mechanisms in vitro, aiming to explore whether LIPUS promotes bone healing through inhibition of the myostatin signaling pathway.

METHODS

Rats with both drill-hole defects and MC3T3-E1 cells were randomly assigned to a LIPUS group and a control group. The LIPUS group received LIPUS treatment (1.5 MHz, 30 mW/cm²) for 20 min/day.

RESULTS

After 21 days, the myostatin expression in quadriceps was significantly inhibited in the LIPUS group, and remodeling of the newly formed bone in the drill-hole site was significantly better in the LIPUS group than that in the control group, which was confirmed by micro-CT analysis. After 3 days, LIPUS significantly promoted osteoblast proliferation; inhibited the expression of AcvrIIB (the myostatin receptor), Smad3, p-Smad3, and GSK-3β; and increased Wnt1 and β-catenin expression. Moreover, translocation of β-catenin from the cytolemma to the nucleus was observed in the LIPUS group. However, these effects were blocked by treatment with myostatin recombinant protein.

CONCLUSIONS

The results indicate that LIPUS may promote bone healing through inhibition of the myostatin signal pathway.

Comparison of effects of LLLT and LIPUS on fracture healing in animal models and patients: A systematic review

The aim of this paper is to study the in vivo potency of low-level laser therapy (LLLT) and low intensity pulsed ultrasound (LIPUS) alone, accompanied by bone grafts, or accompanied by other factors on fracture healing in animal models and patients. In this paper, we aim to systematically review the published scientific literature regarding the use of LLLT and LIPUS to accelerate fracture healing in animal models and patients. We searched the PubMed database for the terms LLLT or LIPUS and/or bone, and fracture. Our analysis also suggests that both LIPUS and LLLT may be beneficial to fracture healing in patients, and that LIPUS is more effective. These finding are of considerable importance in those treatments with a LIPUS, as a laser device may reduce healing time. The most clinically relevant impact of the LIPUS treatment could be a significant reduction in the proportion of patients who go on to develop a nonunion. If it is confirmed that the therapeutic influence is true and reliable, patients will obtain benefits from LIPUS and LLLT. Further clinical trials of high methodological quality are needed in order to determine the optimal role of LIPUS and LLLT in fracture healing in patients.

Comparison of the in vitro effects of low-level laser therapy and low-intensity pulsed ultrasound therapy on bony cells and stem cells

To compare the in vitro effectiveness of Low-Level Laser Therapy (LLLT) and Low Intensity Pulsed Ultrasound (LIPUS) on bony cells and related stem cells. In this study, we aim to systematically review the published scientific literature which explores the use of LLLT and LIPUS to biostimulate the activity or the proliferation of bony cells or stem cells in vitro. We searched the database PubMed for LLLT or LIPUS, with/without bone, osteoblast, osteocyte, stem cells, the human osteosarcoma cell line (MG63), bone-forming cells, and cell culture (or in vitro). These studies were subdivided into categories exploring the effect of LLLT or LIPUS on bony cells, stem cells, and other related cells. 75 articles were found between 1987 and 2016; these included: 50 full paper articles on LLLT and 25 full papers on LIPUS. These articles met the eligibility criteria and were included in our review. A detailed and concise description of the LLLT and the LIPUS protocols and their individual effects on bony cells or stem cells and their results are presented in five tables. Based on the main results and the conclusions of the reviewed articles in the current work, both, LLLT and LIPUS, apply a biostimulatory effect on osteoblasts, osteocytes, and enhance osteoblast proliferation and differentiation on different bony cell lines used in in vitro studies, and therefore, these may be useful tools for bone regeneration therapy. Moreover, in consideration of future cell therapy protocols, both, LLLT and LIPUS (especially LLLT), enhnce a significant increase in the initial number of SCs before differentiation, thus increasing the number of differentiated cells for tissue engineering, regenerative medicine, and healing. Further studies are necessary to determine the LLLT or the LIPUS parameters, which are optimal for biostimsulating bony cells and SCs for bone healing and regenerative medicine.

Low-level laser therapy (780 nm) combined with collagen sponge scaffold promotes repair of rat cranial critical-size defects and increases TGF-β, FGF-2, OPG/RANK and osteocalcin expression

The aim of this study was to evaluate the effect of collagen sponge scaffold (CSS) implantation associated with low-level laser therapy (LLLT) on repairing bone defects. A single 5-mm cranial defect was surgically created in forty Wistar rats, which then received one of the following four interventions (n = 10 per group): no treatment (G0); bone defect implanted with collagen sponge scaffold (CSS) alone (G1); defect treated with low-level laser therapy (LLLT) (wavelength 780 nm; total energy density 120 J/cm² ; power 50 mW) alone (G2); and CSS associated with LLLT treatment (G3). After surgery, animals in each group were euthanized at 21 days and 30 days (n = 5 per euthanasia time group). Bone formation was monitored by X-ray imaging analysis. Biopsies were collected and processed for histological analysis and immunohistochemical evaluation of transforming growth factor-beta (TGF-β), fibroblast growth factor-2 (FGF-2), osteoprotegerin (OPG) and receptor activator of nuclear factor ƙ (RANK). Osteocalcin (OCN) was detected by immunofluorescence analysis. Compared to the G0 group, defects in the 30-day G3 group exhibited increased bone formation, both by increase in radiopaque areas (P < 0.01) and by histomorphometric analysis (P < 0.001). The histopathological analysis showed a decreased number of inflammatory cells (P < 0.001). The combined CCS + LLLT (G3) treatment also resulted in the most intense immunostaining for OPG, RANK, FGF-2 and TGF-β, and the most intense and diffuse OCN immunofluorescent labelling at 30 days postsurgery (G3 vs. G0 group, P < 0.05). Therefore, the use of CCS associated with LLLT could offer a synergistic advantage in improving the healing of bone fractures.

The Effects of Nigella Sativa Seed Extract on Bone Healing in an Experimental Model

The purpose of this study was to histologically evaluate the effects on bone healing of nigella sativa seed extract applied on calvarial defects in an ovariectomized rat model. The study included 32 female rats weighing 280 to 310 g with an average age of 3 months. A defect was created with a trephine burr on each rat calvarium. The rats were divided into 2 groups (control and study) of 8 animals each. All the defects were grafted with a gelatin sponge mixed with normal saline. In the study group, nigella sativa seed extract was applied systemically using an oro-gastric tube. Half of the animals in each group were sacrificed after 2 weeks, and the others after 4 weeks. In the control groups, the defects were not completely filled with regenerated bone. Osteoblast cells were observed more in the study groups. A higher rate of osteoclasts was determined in the control groups. In addition, the nigella sativa group had a statistically greater amount of bone formation than the others group at both 2 weeks and 4 weeks (P <0.05). The systemic application of nigella sativa seed extract demonstrated incredibly positive effects on enhanced bone healing in this experimental osteoporotic model.

Effects of Ankaferd BloodStopper on bone healing in an ovariectomized osteoporotic rat model

Bone defects resulting from oncological surgical resections, congenital facial anomalies, trauma or infection represent a significant and common clinical problem. The present study aimed to evaluate the effects of a commercially-available medicinal plant extract product, Ankaferd BloodStopper (ABS), on bone healing. The present study was performed on 24 female ovariectomized (OVX) rats. A defect on each rat calvarium was created using a trephine burr prior to the rats being divided into two groups. Defects were grafted with a gelatin sponge soaked with normal saline (control group) or plant extract (experimental group). Half of the animals were sacrificed after 2 weeks and the others after 4 weeks. In the control group, the defects were not filled with regenerated bone. By contrast, in the experimental group, all defect areas had an increased amount of regenerated bone and connective tissue. Osteoblastic activity appeared to be greater in the experimental group however, osteoclastic activity was observed to be higher in the control group. At 2 and 4 weeks, there was a significant difference in the amount of newly regenerated bone observed in the experimental group compared with the control group (P<0.05). Therefore, the results of the present study indicated that local ABS application had a positive effect on bone healing in the OVX rat model.

Evaluation of the effects of the low-level laser therapy on swelling, pain, and trismus after removal of impacted lower third molar

BACKGROUND

In current study we aimed to examine the effect of a low-level laser therapy on the pain, mouth opening and swelling of patients whose impacted 3rd molar tooth was extracted in addition measurement volumetrically to the edema with 3dMD face system.

METHODS

It was surveyed 15 patients who had bilateral symmetric lower 3rd molars. Surgical sides of patients were randomly separated into two groups: the study group and the control group. It was applied extra oral low-level laser therapy (LLLT, 0.3 W, 40 s, 4 J/cm(2)) to the study group (n = 15) after the surgical operation and on the 2nd day. Only routine postoperative recommendation (ice application) was made in the control (n = 15) group. The maximum mouth opening, pain level and facial swelling evaluated. 3dMD Face® (3dMD, Atlanta, GA) Photogrammetric System was used to evaluate volumetric changes of the swelling.

RESULTS

There was no statistically significant difference in the edema and interincisal opening between the groups and the pain level in the laser group was significantly lower than in the control group on the 7(th) postoperative day.

CONCLUSIONS

Although there were decreasing trismus, swelling, and pain level, with this LLLT, there was significant difference only in the 7th day pain level in the laser group compared with the control group.

Dietary arginine silicate inositol complex increased bone healing: histologic and histomorphometric study

Background

Arginine silicate inositol complex (ASI; arginine 49.5%, silicon 8.2%, and inositol 25%) is a novel material that is a bioavailable source of silicon and arginine. ASI offers potential benefits for vascular and bone health.

Objective

The aim of this study was to evaluate the potential effects of ASI complex on bone healing of critical-sized defects in rats.

Methods

The rats were randomly assigned to two groups of 21 rats each. The control group was fed a standard diet for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The ASI group was fed a diet containing 1.81 g/kg of ASI for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The calvarial bones of all the rats were then harvested for evaluation.

Results

Osteoblasts and osteoclasts were detected at higher levels in the ASI group compared with the control group at days 7, 14, and 28 of the calvarial defect (P<0.05). New bone formation was detected at higher levels in the ASI group compared with the controls at day 28 (P<0.05). However, new bone formation was not detected at days 7 and 14 in both the groups (P>0.05).

Conclusion

ASI supplementation significantly improved bone tissue healing in rats with critical-sized defects. This study demonstrated that ASI can enhance bone repair and has potential as a therapeutic regimen in humans.

Effect of caffeic acid phenethyl ester on bone formation in the expanded inter-premaxillary suture

BACKGROUND

Narrow maxilla is a common problem in orthodontics and dentofacial orthopedics. To solve this problem, a procedure called rapid maxillary expansion (RME) has been used. However, relapse tendency is a major problem of RME. Although relapse tendency is not clearly understood, various treatment procedures and new applications have been investigated. The present study aimed to investigate the possible effectiveness of caffeic acid phenethyl ester (CAPE) on new bone formation in rat midpalatal suture after RME.

MATERIALS AND METHODS

Twenty male Sprague Dawley rats were used in this study. The animals were randomly divided into two groups as control and CAPE group. In the CAPE group, CAPE was administered systemically via intraperitoneal injection. RME procedure was performed on all animals. For this purpose, the springs were placed on the maxillary incisors of rats and activated for 5 days. After then, the springs were removed and replaced with short lengths of rectangular retaining wire for consolidation period of 15 days. At the end of the study, histomorphometric analysis was carried out to assess new bone formation.

RESULTS

New bone formation was significantly greater in the CAPE group than the control group (P<0.05). CAPE enhances new bone formation in midpalatal suture after RME.

CONCLUSION

These results show that CAPE may decrease the time needed for retention.