**5. Conclusion**

*Clinical Implementation of Bone Regeneration and Maintenance*

din E2 (PGE2) in the osteoblasts [88, 89].

proliferation, and cell differentiation.

gene-2 [88, 89].

current study.

fracture.

**4.4 Clinical significance**

differentiation. In vitro studies have shown that LIPUS leads to the increased expression of genes related to the bone formation. These genes include osteocalcin, aggrecan, bone sialoprotein, insulin-like growth factor-I, collagen types I and X, transforming growth factor beta, alkaline phosphatase, and runt-related

Additionally, LIPUS treatment also promotes the synthesis of protein and uptake of calcium by osteoblasts. LIPUS treatment also plays an important role in the remodeling of the bone by stimulating the cyclooxygenase pathway. LIPUS increases the expression of COX-2 gene that promotes the synthesis of prostaglan-

Huang et al. [90] concluded in his recent study in vitro that the LIPUS stimulates the expression of BMP-2 which means positive effects of LIPUS on osteogenesis. In vitro study by Sun et al. [91] showed that LIPUS upregulated osteoblasts and downregulated osteoclasts in the rat alveolar mononuclear cells. Lu et al. [92] explained that the mechanical signals from LIPUS could stimulate osteoblasts by means of gene expression and stimulated proteins that were translated by these genes causing activation of apoptotic genes and osteogenesis in acceleration of the tissue remodeling and expedite clinical outcomes as we have seen in our

Iwanabe et al. [93] demonstrated in his recent study in vitro that the number of cells at 5 days after LIPUS exposure was significantly higher than that of the control, while that at 7 days was about 35% higher than that of the control. This means that LIPUS has the potential to be an effective agent in inducing migration,

In vitro as well as in vivo studies, using animal models showed that LIPUS has stimulatory effect on cellular activity, release of cytokines, and bone healing [94]. Cell physiology is directly affected by LIPUS. It increases the uptake of calcium by the developing cartilage and bone cells in the culture. It also stimulates a large number of genes that help in the process of healing [62]. Barzelai et al. [95] reported that LIPUS not only modulates the expression of genes, but it also enhances the process of angiogenesis and increases the flow of blood at the site of

• LIPUS may be utilized as treatment modality to save dental implant with questionable primary stability during stage I implant placement, with the aim of achieving adequate osseointegration and improving implant success.

• LIPUS can be recruited to promote and accelerate healing time particularly in patients with medical conditions such as diabetes mellitus and other diseases.

• The clinical results shown in this study confirmed that low-intensity pulsed ultrasound (LIPUS) presents low toxicity, noninvasiveness, and repeated

• Application of LIPUS on dental implant wound at 2 weeks postoperative seems to be a favorable time when the acute inflammatory phase has subsided and the

• RFA gives clear image about the stability of the implant and the condition of

applicability. The risk of thermal injury is unfounded.

cellular proliferative phase has actively began.

the bone around implant.

**22**
