This study was designed to examine the effects of bone morphogenetic protein-2 (BMP-2) on bone response at palatal site using gelatin hydrogel in ovariectomized (OVX group) and normal female rats (Normal group). The experimental sites in both groups were divided into two sites: implantation with gelatin hydrogel containing BMP-2 (BMP site) and gelatin hydrogel only (Gel site). Four weeks after implantation, new bone formation was observed at every site and the new bone volume (NBV) of the BMP site was significantly greater than that of the Gel site of both groups (p<0.05). The NBV of every site in Normal group was significantly greater than that of the same experimental site in OVX group (p<0.05).

These results suggest that the gelatin hydrogel containing BMP-2 induce new bone formation at palatal site even in estrogen-deficient rats, whereas the new bone volume is less than in normal rats.

Tooth staining is not detrimental to dental health, but it is a dental problem that occurs frequently. Teeth with coloring problems do not give a healthy impression. The mechanism of tooth staining should be clarified to resolve this embarrassment, but much remains unknown. Tannin is a pigment found in various plants and is known in food and drink as the pigment component of persimmons and wine. In this study, we experimentally stained enamel, which constitutes the superficial layer of the crown of teeth, by reacting with tannin and analyzed the results both visually and digitally, and observed whether the microstructure changed or not, and discussed the relationship with the reaction time.

Although fine dust is generated in large quantities during chairside adjustment and polishing of dental work during dental treatment, it may be hazardous to the health of patients, dentists, and dental staff. Previous studies on the fabrication of dust derived from dental materials and exposure to cultured cells have reported that lactate dehydrogenase and reactive oxygen species are released, causing cell cycle disruption. In this study, we fabricated dental CAD/CAM fine powders using a collagen-based three-dimensional (3D) culture method instead of the conventional two-dimensional (2D) culture method and evaluated cell viability in 2D and 3D cultures. Cell viability was evaluated by 2D and 3D cultures. Cell viability was also evaluated by measuring oxidative stress in 2D cultures. The results showed that exposure of cells to dust caused oxidative stress and the 3D culture method reduced cell viability, similar to the results for the 2D culture method. Adequate dust control measures should be taken in dental treatment rooms using extraoral vacuum, surgical masks, and gloves.