The Roles of Strontium Ions in Regenerative Dentistry: Cells Interaction, Mechanism of Action, and Future Perspective

Abstract

Strontium (Sr) ions play as a key role in the regeneration of hard tissues such as bones and teeth. Regarding the role of Sr ions in the human body, many studies have been conducted, which may be applied to hard tissue regeneration and regeneration in dentistry. In the mechanism of bone remodelling, Sr ions have a dual effect on bone metabolism: inhibit bone absorption and stimulate bone formation. From the chemical point of view, substitution of Calcium (Ca) ions with Sr in the hydroxyapatite (HA) structure will decrease its crystallinity, thus influence bone resorption process. In dentistry, diffusion of additional Sr ions from dental restorative material has also been known to have an important impact on permanent dentin in the body. In this study, 191 titles from MEDLINE (PubMed) databases and 15 titles from the Scopus database were screened to meet the relevant topic of the study. From the included studies, it was confirmed that Sr ions seem to enhance the bone quality around the implant and the osseointegration of the implant. The unique dual mode of action of Sr ion has two possible mechanisms. They balance bone renewal by activating Ca (or other cations) sensing receptors and increasing the expression of osteoprotegerin (OPG) and reducing the expression of RANK ligand by osteoblast. In various compromised cases such as patient with osteoporosis, Sr-substituted scaffold can be an option when regenerative dental therapy is needed. Further investigation is needed to fully understand the role of Sr ions in regenerative pathways and its cellular mechanism to result better choices in regenerative therapy.