Objective: The antibacterial properties and bonding strength of 3M orthodontic adhesive resin modified by chlorhexidine acetate (CHA) composite mesoporous silica were investigated. Methods: CHA with different mass fractions was encapsulated in mesoporous silica nanoparticles (MSNs) (denoted CHA@MSNs). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the samples. The 3M Z350XT flow resin was divided into 4 groups: group A: 3M+CHA@MSNs (0%); group B: 3M+CHA@MSNs (3%); group C: 3M+CHA@MSNs (5%); and group D: 3M+CHA@MSNs (6.4%), with mass scores of 0%, 3%, 5%, and 6.4%, respectively. The shear strength of the modified adhesive was tested by a universal electronic material testing machine, the adhesive residue was observed by a 10 × magnifying glass, and the adhesive Remnant index (ARI) was calculated. The four groups of modified adhesives were cultured with Streptococcus mutans. The OD540 value of the bacterial solution was measured by a spectrophotometer, and the amount of plaque attachment was observed by scanning electron microscopy to evaluate the antibacterial performance of the adhesives. Results: Infrared spectroscopic analysis of CHA@MSNs showed that CHA was successfully loaded onto MSNs. Under scanning electron microscopy, it could be seen that, after Cha was combined with MSNs, the structure of MSNs changed, as the boundary was fuzzy and aggregated into a layered structure. A comparison of shear strength revealed a statistically significant difference between the groups containing CHA@MSNs and the groups without CHA@MSNs (P<0.05). The value of the shear strength in group D decreased the most, while there was no statistically significant difference between group B and group C (P > 0.05). There was no statistical significance across all groups (P > 0.05), suggesting that the addition of CHA@MSNs had little effect on the bracket shedding. The OD540 value of bacterial fluid indicated that the difference among groups A, B and C was statistically significant (P < 0.05), and the antibacterial effect of group C was the best; there was no statistically significant difference between group C and group D (P > 0.05). Conclusions Therefore, adding 5% CHA@MSN antibacterial agent significantly improved the antibacterial effect and did not affect the bond strength.

ObjectiveTo investigate the status of tooth loss in people aged 50 and above, so as to understand their oral health status and provide scientific evidences for promoting oral health of middle-aged and elderly people. MethodsA total of 400 patients who visited the department of stomatology at Sijing Hospital in Songjiang District of Shanghai were performed oral health examinations and their information was collected according to the national epidemiological survey standards for oral health. ResultsThere were statistically significant differences in tooth loss among people aged 50 and above with different ages, educational levels, occupations, types of medical insurance and chronic diseases (P<0.05), but gender and monthly income had no statistically significant correlations with tooth loss (P>0.05). Among lifestyle factors, smoking, alcohol consumption and tea drinking had no statistically significant impacts on the number of remaining teeth (P>0.05), but toothbrushing frequency, flossing frequency, toothpick use frequency, toothbrush replacement frequency, and tooth loosening were statistically associated with the number of remaining teeth (P<0.05). Multiple linear regression analyses indicated that a total of 7 related factors including age, educational level, occupation, medical payment type, chronic disease, tooth loosening and toothpick use frequency were significantly associated with the number level of remaining teeth in individuals aged 50 and above. ConclusionAge, chronic disease, and tooth loosening were influencing factors affecting the number of teeth left in people aged 50 and above. It is recommended to strengthen oral health education and improve healthcare awareness to reduce the risk of tooth loss in people aged 50 and above.

Lymphangioleiomyomatosis (LAM) is a rare, multisystemic, low-grade neoplasm character-ized by diffuse cystic lesions in the lung.In recent years, emerging imaging examination such as ⁶⁸Ga-NEB PET-CT scan provides efficient and precise non-invasive diagnostic methods to detect lymphatic circulation abnormalities in LAM patients. The long-term efficacy and safety of sirolimus for LAM has accumulated further evidence, and genetic profiling studies have unveiled more information of genetic mechanisms. Prognosis of LAM has been much improved. We briefly reviewed the research advances of LAM in China and other countires.