Periodontal disease is a chronic inflammatory disease that leads to the destruction of periodontal tissues. Periodontal tissue regeneration is the ultimate goal of periodontal therapy; however, current regenerative treatments still have limitations. In recent years, periodontal regeneration through stem cell transplantation has attracted considerable attention, and many studies have demonstrated its efficacy. On the other hand, the engraftment of transplanted stem cells is limited, and modulatory effects on wound healing mediated by humoral factors, dead cell-derived factors, and extracellular vesicles have emerged as important mechanisms of periodontal regeneration. This review outlines the historical development of stem cell-based periodontal regeneration research and discusses its future perspectives.

Enamel and cementum function as hard tissue barriers that protect dentin from external stimuli. However, disruption of these barriers due to dental caries, abrasion, erosion, periodontal disease, or periodontal surgical procedures may result in dentin exposure and dentin hypersensitivity through dentinal tubules. This mini-review summarizes the pathological condition of dentin exposure following hard tissue barrier breakdown and outlines the mechanisms and limitations of conventional dentin hypersensitivity suppressants. Particular attention is given to calcium carbonate biomaterials and their potential biological activity. Calcium carbonate–based dentin hypersensitivity suppressants have been reported to occlude dentinal tubules and may influence cellular responses through calcium ion release. These materials may represent a new biomaterial-based strategy for dentin management after hard tissue barrier breakdown.

Cellular biological functions are commonly important indicators in cellular research. Modification and imaging of cellular biological functions are indispensable for the development of cellular research. Nanocarriers-based intracellular delivery system capable of effectively delivering modifiers or probes into cells are effective to realize the modification and imaging of cellular biological functions. This review briefly explains the preparation strategy of nanocarriers for intracellular delivery and introduces concrete examples of modification and imaging of cellular biological functions based on intracellular delivery system.

The biological safety of toothpaste components is of great interest not only to dental hygienists and dentists but also to general consumers. This study investigated the cytotoxicity of representative chemical substances that make up paste-type toothpaste. The composition of toothpaste includes basic components such as cleaning agents, humectants, foaming agents, binders, and fragrances/preservatives, as well as four types of chemical substances added as medicinal ingredients. Cell viability, a fundamental indicator of biological safety, was examined using mouse-derived Balb c/3T3 cells. The purity of the chemical substances used was almost at reagent level. The results for the cell viability of chemical substances classified as basic components showed that many had high cell viability and low cytotoxicity compared to medicinal ingredients. In particular, no problems were observed in terms of cytotoxicity for cleaning agents and humectants. However, flavorings and preservatives showed somewhat low values. While all medicinal ingredients showed low cell viability, it increased with higher dilution concentrations. This study evaluated four representative medicinal ingredients based on cell viability, but actual commercially available products use a wider range of chemical substances, and further investigation of a broader range of chemicals is necessary.