# Effects of Magnetic Stimulation on Dental Implant Osseointegration: A Scoping Review
## 3 Results
### In Vivo Studies
#### 3.2.2 Pulsed ElectroMagnetic Fields  
Two studies focused on the effects of PEMF on implant osseointegration in rats. [PERSON] et al. [51] found that rats receiving PEMF twice a day (in sessions of 30 min) had increased ossification and BIC percentages after 20 days. Recently, [PERSON]'s group [48] showed that PEMF exposure positively affected bone parameters such as volume percentage, trabecular thickness and bone mineral density (BMD) and also removal torque and BIC of implants placed in rats. However, different times of exposure per day led to different results at various follow-ups. Eight studies evaluated the effects of PEMF on implant osseointegration in rabbits. [PERSON] et al. [50] demonstrated that implants with a PEMF-emitting healing cap showed a 48% and 42% greater BIC (after 2 and 4 weeks, respectively) compared to implants without exposure. More specifically, the authors also reported that BIC was not statistically affected by PEMF in the apical region, suggesting a putative relationship between the area of bone regeneration and the distance from the PEMF emitter. The dependence of the BIC on the intensity of the PEMF and on the time-interval of exposure was investigated by [PERSON] et al. [55]. Specifically, rabbits with implants treated with different intensities of PEMF (0.2 mT-0.3 mT-0.8 mT) showed increased BIC compared to animals with unexposed implants. We note that results seemed not to show dependence on PEMF intensity, treatment schedule and duration (measurements taken up to four weeks). Conversely, at longer exposure time (8 week treatment), [PERSON] et al. [53] demonstrated that there was a higher number of osteoblasts and new trabecular bone formation around implants exposed to PEMF compared to implants without PEMF exposure. The influence of exposure cycle, in terms of hours/day, was also tested: [PERSON] et al. [56] found that rabbits receiving PEMF stimulation (10 or 5 h/day) showed greater bone formation around porous Ti implants compared to unexposed controls and that 10 h/day exposure led to a greater bone formation compared to 5 h/day exposure. Similarly, [PERSON] et al. [36] found that implants placed in rabbits receiving PEMF (2 mT; 75 Hz) increased new trabecular bone formation compared to controls without PEMF. PEMF also stimulated the expression of osteogenic markers, such as RUNX2, BMP2 and OCN. In contrast to the reported observations, the histological evaluation by [PERSON] et al. [54] showed no difference in terms of peri-implant bone and removal torque between implants with or without PEMF stimulation, although details of important variables such as duration and intensity of the electromagnetic stimulation were not provided. Studies on rabbits affected by systemic pathologies are also available. Diabetic rabbits receiving PEMF stimulation showed better results in terms of peri-implant bone formation and bone histomorphometry parameters compared to the diabetic control group [21]. In a different study [49], the same authors found that in glucocorticoid-induced osteopororotic rabbits PEMF exposure significantly affected the peri-implant bone formation around porous Ti implants, leading to a histomorphometry of the PEMF-exposed glucocorticoidoidtreated animals similar to that of the controls (healthy rabbits). The authors also evaluated the effects of PEMF on osteoblast and osteocyte functionality by assessing circulating levels of osteoblast-related factors such as oscx, OCN, RUNX-2 and bone-resorbing cytokines (i.e., serum TRAcP5b and CTX-1) showing a PEMF-dependent increase in their level [49]. In addition, [PERSON] et al. [34] found that PEMF stimulation (1 mT 2 h/day) led to increased bone formation, measured by microcomputed tomography and histomorphometry, on the porous surface of Ti implants placed in the femurs of osteoporoptic rabbits after 6 and 12 weeks. Conversely, [PERSON] et al.