Effects of noninvasive electrical stimulation on peri-implant osteogenesis in rabbit

Objectives: The procedure that enhances osteogenesis and shortens the healing period is required for successful implant therapy. It has been introduced that osteogenesis is enhanced by the generation of electric field. Many researchers have demonstrated that application of electric and electromagnetic field promote bone formation. It also has been shown that electrical stimulation enhances peri-implant bone formation. Therefore, we tried to evaluate the effect of noninvasive electrical stimulation using negatively charged electret such as polytetrafluoroethylene(PTFE) on the peri-implant bone healing. Methods: After titanium implants were installed in the proximal tibial metaphyses of eight New Zealand white rabbit, negatively charged PTFE membrane fabricated by corona discharge was inserted into the inner hole of the experimental implant and non-charged membrane was applied into control implant. After 4 weeks of healing, histomorphometric analysis was performed to evaluate peri-implant bone response. Results: The histomorphometric evaluations demonstrated experimental implant tended to have higher values in the total bone-to-implant contact ratio (experimental; 49.9 ± 13.52% vs control; 37.5 ± 19.45%), the marrow bone contact ratio (experimental; 34.94 ± 13.32% vs control; 24.15 ± 13.69%), amount of newly formed bone in the endosteal region (experimental; 1.00 ± 0.30mm vs control; 0.61 ± 0.24mm) and bone area in the medullary canal(0~500um zone) (experimental; 13.55 ± 4.98% vs control; 9.03 ± 3.05%). The mean values of the amount of newly formed bone (endosteal region) and bone area(medullary canal) of the experimental implant demonstrated a statistically significant difference as compared to the control implant(p<0.05). Conclusion: Noninvasive electrical stimulation using negatively charged electret effectively promoted peri-implant osteogenesis in this study. This method is expected to be used as one of the useful electrical stimulation for enhancing bone healing response in the implant therapy.