# Effects of Magnetic Stimulation on Dental Implant Osseointegration: A Scoping Review
## 3 Results
### In Vitro Studies
#### 3.1.2 Pulsed ElectroMagnetic Fields  
Nine studies focused on the effects of PEMF on bone-derived cells cultured on Ti surfaces. [PERSON] et al. [38] tested how PEMF (0.2 mT) influenced the behavior of rat primary osteoblasts on implant surfaces of different chemical compositions at 24, 48 and 72 h exposure. Specifically, discs of commercially pure Ti (cpTi) and Titanium-Zirconium alloy (TiZr) were used. The effect of PEMF exposure in terms of cell viability (biocompatibility), cell proliferation rate, and alkaline phosphatase was clearly stimulative on osteoblasts cultured on the cpTi surface compared to TiZr discs.  
[PERSON] et al. [37] analyzed the response of rat osteoblasts cultured on surfaces with different topographies: polished flat surfaces, sand-blasted with large grit and acid etched surfaces (micro-topographic modification) and anodized nanotubular-structured surfaces (nano-topographic modification). The authors reported that PEMF stimulation led to higher osteoblast adhesion and proliferation and augmentation of ECM mineralization onall the tested Ti surfaces, with nano-topography showing the better PEMF-dependent increment with respect to the control group of unexposed cells. Importantly, no differences in rate proliferation were observed between the different surfaces without PEMF stimulation.  
[PERSON] et al. analyzed the effects on osteoblast-like cells in four consecutive studies [39, 40, 41, 42], after the application of PEMF (2 mT, 75 Hz). In two of these studies, human osteosarcoma cells (SAOS-2) were cultured on Ti devices with a complex texture, Ti sintered grids or Ti fiber-mesh sheets, showing an increased proliferation rate and the concomitant production of ECM components such as decorin, osteopontin, and type-I collagen after PEMF stimulation [40, 41]. The authors obtained similar results by culturing the same cell type on Ti plasma spray surfaces: once again, a higher proliferation rate and production of an autologous ECM were observed with PEMF exposure [39, 42].  
[PERSON] et al. [35] reported similar effects on ECM deposition using human bone marrow mesenchymal stem cell (hBM-MSCs), cultured on a TiO\({}_{2}\) surface of unspecified topography. In particualr, the authors showed that the same PEMF intensity used by [PERSON]'s group (2 mT; 75 Hz) led to a higher expression of Runx-2, Bone SiloProtein (BSP), Osterix, OSC, BMP-2 and a higher production of ALP, type-I collagen, type-III collagen and FN. Furthermore, as complementing data, they analized the ion flux, showing that the exposure was also able to enhance cellular Ca\({}^{2+}\) currents, especially in the initial phase of the osteogenic process, with a higher intracellular Ca\({}^{2+}\) concentration, and the externalization of type-I collagen and collagen network formation.  
Finally, two publications, analyzing PEMF effects both in vivo and in vitro, can be described partially in this section for their in vitro results [34, 36]. Two different research groups corroborated the positive effect of pulsed stimulation on cell growth independently on the used models (BM-MSC from osteoporoptic rabbits [34] and osteoblast-like MC3T3-E1 cells [36]) and at very different exposure times and peak intensities of PEMF (4-7 days/1 mT and 6-12 weeks/2 mT, respectively).