Effects of the Pulsed Electromagnetic Fields on Experimental Periodontitis and Estrogen Deficiency

Abstract

Periodontitis is an inflammatory disease resulting from a complex polymicrobial infection that causes tissue destruction in susceptible individuals. Osteoporosis has been associated with greater clinical attachment loss in patients with periodontitis. Experimental studies have shown positive results in the treatment of osteoporosis through pulsed electromagnetic field (PEMF) stimulation. The aim of this study was to evaluate the effects of PEMF in the presence of estrogen deficiency associated with periodontitis, verifying its role in bone metabolism and in the inflammatory response. Sixty rats were divided into four groups: Sham surgery + ligature-induced periodontitis (P); Sham surgery + ligatureinduced periodontitis + PEMF therapy (P + PEMF); Ovariectomy surgery + ligature-induced periodontitis (P + OVX); Ovariectomy surgery + ligature-induced periodontitis + PEMF therapy (P + OVX + PEMF). The area of bone loss in the furcation region (BL), connective tissue attachment loss (CTAL) and alveolar bone loss (ABL), BV/TV and BMD were evaluated. In addition to immunohistochemical labelling of RANKL, OPG, and TRAP and the inflammatory response of interleukin (IL)-1b, IL-6, TNF-α, IL-10, and vascular endothelial growth factor. P + OVX showed significant BL in relation to P + PEMF and the greatest CTAL and ABL. P + OVX and P + OVX + PEMF showed a significant reduction in BV/TV (%). P and P + PEMF showed a significantly lesser amount of Tb.Sp (mm) while P + OVX and P + OVX + PEMF showed a lesser of Tb.N. P + PEMF had the greatest BMD. P + OVX presented higher RANKL and lower OPG immunolabeling than other groups. P + PEMF and P + OVX + PEMF showed a reduction on all biomarkers evaluated. The application of PEMF seems to attenuate the effects of bone loss in the presence of periodontitis and ovariectomy. Bioelectromagnetics. 43:426-437, 2022.

Gathering Evidence to Leverage Musculoskeletal Magnetic Stimulation Towards Clinical Applicability

“…PEMF effects on osteoclasts may also be related to the desensitization of osteoblasts to inflammation initiators, such as IL-1β, [204] resulting in a decreased expression and secretion of IL-6 and RANKL, among other cytokines, by these cells. [111,115,125] In vitro experiments suggest two other parallel and interacting mechanisms of action by which IC may lead to decreased osteoclast and increased osteoblast activities. PEMF was observed to induce, at an early phase, an increase in mitochondrial activity and production of reactive oxygen species (ROS, •O 2 À and H 2 O 2 ), resulting in increased non-cytotoxic oxidative stress.…”

“…[205] Potential contributors to the decreased circulating levels of inflammatory cytokines are the decreased levels of angiogenic factors like VEGF. [115] PEMF can also promote other stress-related processes and associated tissue repair cascades, by inducing the expression of heat shock proteins like hsp70, whose gene's promoters have electromagnetic fields (EMF)-responsive sequences. [206,207] Noteworthy, in a peripheral blood mononuclear cells (PBMCs) model of Alzheimer's disease PEMF was reported to decrease the expression of miRNAs, namely miR-107, miR-335-5p, and miR-26b-5p, that regulate the translation of mRNAs associated with transcription factors, growth factors, enzymes, and transporters (e.g., SP1, IGFR1 and MAPK, SLC17A6, respectively).…”

“…PEMF of 15 Hz, 1 mT, applied to rats with periodontitis (with and without OVX) for 3 h day −1 over 3 weeks, has (in both cases) attenuated the effects of bone loss (+27.8% BMD), increased bone volume‐to‐total volume ratio (BV/TV + 28.6%), improved bone microarchitecture (+11.5% Tb.N, −8.0% Tb.S) and reduced markers of inflammatory response such as IL‐1β, IL‐6, TNF‐α, IL‐10 and vascular endothelial growth factor (VEGF). [ 115 ] PEMF of 15 Hz, 2.4 mT, for 8 h day −1 over 10 weeks, improved bone biomechanical properties (+15.2% maximum load; +46.6% elastic modulus), reduced bone loss (+41.8% BMD; +1.83‐fold BV/TV), enhanced bone microarchitecture (+54.7% Tb.N, +17.6% Tb.Th, −18.6% Tb.S) and reduced structure model index (SMI, −31.7%). [ 116 ] OVX‐induced bone loss was also avoided when OVX mice were treated with similar PEMF: 15 Hz of square wave pulses and 2.4–2.6 mT MF strength, for 1 h day −1 over 8 weeks.…”

“…PEMF effects on osteoclasts may also be related to the desensitization of osteoblasts to inflammation initiators, such as IL‐1β, [ 204 ] resulting in a decreased expression and secretion of IL‐6 and RANKL, among other cytokines, by these cells. [ 111,115,125 ]…”

Melatonin Decreases Alveolar Bone Loss in Rats with Experimental Periodontitis and Osteoporosis: A Morphometric and Histopathologic Study

“…Osteoporosis is a skeletal disorder that debilitates bones and increases fracture risk by decreasing bone density and increasing fragility due to altered bone strength, microarchitecture, and metabolism [ 8 ]. Both osteoporosis and periodontitis are chronic inflammatory prevalent diseases that cause changes in bone metabolism.…”