The immune-stromal cell interactions play a key role in health and diseases.In periodontitis,the most prevalent infectious disease in humans,immune cells accumulate in the oral mucosa and promote bone destruction by inducing receptor activator of nuclear factor-κB ligand(RANKL)expression in osteogenic cells such as osteoblasts and periodontal ligament cells.However,the detailed mechanism underlying immune-bone cell interactions in periodontitis is not fully understood.Here,we performed single-cell RNA-sequencing analysis on mouse periodontal lesions and showed that neutrophil-osteogenic cell crosstalk is involved in periodontitis-induced bone loss.The periodontal lesions displayed marked infiltration of neutrophils,and in silico analyses suggested that the neutrophils interacted with osteogenic cells through cytokine production.Among the cytokines expressed in the periodontal neutrophils,oncostatin M(OSM)potently induced RANKL expression in the primary osteoblasts,and deletion of the OSM receptor in osteogenic cells significantly ameliorated periodontitis-induced bone loss.Epigenomic data analyses identified the OSM-regulated RANKL enhancer region in osteogenic cells,and mice lacking this enhancer showed decreased periodontal bone loss while maintaining physiological bone metabolism.These findings shed light on the role of neutrophils in bone regulation during bacterial infection,highlighting the novel mechanism underlying osteoimmune crosstalk.

ABSTRACT This study aims to compare the effect of fTCP-contained toothpaste in combination with 950 ppm fluoride on primary dentin caries surface to ordinary 1100 ppm fluoride toothpaste by using estimation statistics. Dental caries with deep lesion and dentin exposure from nine primary teeth were cut into two equal parts and randomly divided into two groups in a before-after study. Each group was brushed with one type of toothpaste two times per day for 28 days and rested in artificial saliva. SEM images of cavity bottom surfaces and energy-dispersive X-ray spectrometry (EDX) were used to determine the percentage of calcium (Ca), phosphorus (P), fluoride (F) and oxygen (O) at six continuous measured areas from the surface of the cavity bottom into 45 µm depth before and after brushing. About 95% confidence interval of the mean difference was calculated by performing bootstrap resampling with 5000 resamples followed by comparison analysis. The percentage of Ca, P, F, O was shifted after treatment. There was no difference between the two groups. The SEM images reflected a similar illustration of EDX data. The combination of fTCP and 950 ppm fluoride in toothpaste showed equivalent effectiveness to the 1100 ppm fluoride toothpaste in primary dentin caries.
Fluorosis, Dental ; Dental Caries