The impact of Er:YAG laser combined with fluoride treatment on the supragingival plaque microbiome in children with multiple caries: a dynamic study.

BACKGROUND: As a minimally invasive tool for caries prevention tool, the pulsed erbium:yttrium-aluminum-garnet (Er:YAG) laser is being used in a large number of studies. Microorganisms are extremely vital in the occurrence and development of dental caries. However, the impact of Er:YAG laser irradiation combined with fluoride on the dynamic microbial changes that occur in dental plaques is still uncertain. In this study, we examined the effect of an Er:YAG laser combined with fluorine on supragingival microbial composition and diversity in children with multiple caries. METHODS: In this study, dental plaque samples (n = 48) were collected from 12 children with over 8 filled teeth. Supragingival plaques from left mandibular molars before (CB) and after fluoride treatment (CA) and right mandibular molars before (EB) and after fluoride+Er:YAG laser treatment (EA) were collected from each patient. In CB and EB groups, the samples were collected just before the treatments. In CA and EA groups, the samples were collected 1 month after treatments. Then, all specimens were subjected to 16S rRNA high-throughput sequencing to investigate the changes in microbial composition and diversity in mandibular molar supragingival plaques before and after fluoride or fluoride+Er:YAG laser treatment. RESULTS: The dental plaque microbial diversity was higher in the EA group than in the EB group (baseline levels), and the microbial composition changed in EA group compared with EB group (P < 0.05). The levels of microorganisms associated with caries occurrence, including Proteobacteria, Fusobacteria, and Bacteroidetes, declined, while the levels of Faecacterium, Fastidiosipila, Vibrio, and Shewanella increased in EA group compared with EB group. The declines in Firmicutes, Streptococcus, Fusobacterium, and Veillonella levels were significantly lower in the EA group than in the CA group. CONCLUSION: The combined application of the Er:YAG laser and fluoride may be more effective than using fluoride alone in reducing the proportion of cariogenic bacteria, increasing the diversity of plaque microorganisms, and further promoting the microecological balance.

Research Progress on Diagnosis and Treatment of Oral Cancer Guided by Nanomedicine Technology / 肿瘤防治研究

Squamous cell carcinoma of the head and neck is the sixth most common cancer in the world, 40% of which occurs in the oral cavity. Although the level of early diagnosis and treatment of oral cancer has been significantly improved, the 5-year survival rate of advanced patients is still low. Nanomedical technology has the ability to efficiently deliver drugs, nucleic acids and contrast agents, enhance the tolerance of patients and improve the quality of life while improving the accuracy of diagnostic technology and the efficacy of chemotherapeutic drugs, thus providing a broad prospect for the diagnosis and treatment of oral cancer. This paper reviews the research progress of the application of nanomedical technology in both diagnosis and treatment of oral cancer.

The effect of basic fibroblast growth factor on the proliferation of gingiva-derived mesenchymal stem cells / 实用口腔医学杂志

Objective:To investigate the effect of basic fibroblast growth factor(bFGF) on the proliferation of gingiva-derived mesenchymal stem cells(GMSCs) in vitro.Methods:GMSCs were isolated from healthy gingival tissue samples and identified.GMSCs of passage 4 were treated by bFGF at 0,0.5,1,5,10,20 ng/ml respectively for 1-9 d.The proliferation of the cells was evaluated using CCK-8 kit.Results:bFGF at 0.5-20 ng/ml increased GMSCs proliferation.0.5-10 ng/ml of bFGF showed dose and time dependant proliferation promoting effect on GMSCs.Conclusion:bFGF can increase GMSCs proliferation ability in a dose and time dependant manner.

In vitro study on the curvatures of root canal of maxillary first premolars among adolescents in Guangdong province / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the root canal curvatures of adolescents' maxillary first premolars in Guangdong province and the differences between male and female were studied.</p><p><b>METHODS</b>200 maxillary first premolars among adolescents in Guangdong Province (100 males and 100 females) were numbered in proper. After access preparation, a K-file was inserted into the canal until the tip of the file was just seen at the apical foramen. Then standardized periapical images were taken from mesial-distal and buccal-lingual directions with radio visio graphy. The angle of canal curvature (CCA) was determined according to the method described by Schneider. Then the curved canals whose angle were more than 5 degrees were chosen, and the canal access angle (CAA), curvature height (X) and curvature distance (Y) were determined according to the method described by Günday. Linear correlations of the measurements were analyzed.</p><p><b>RESULTS</b>59.21% of the total roots were curved in buccal-lingual directions. The incidence rates of males' and females' were 49.74% and 68.98%, respectively. 41.05% of the total roots were curved in mesial-distal directions. The incidence rates of males' and females' were 36.27% and 45.99%, respectively. 6.84% of the total roots were S-shaped curves. 4.15% and 9.63% of canals from male and female were S-shaped curves, respectively. The curvatures of single root canals between male and female had statistical differences in buccal-lingual directions (P<0.05). The curvatures of the lingual root canals from females in buccal-lingual directions and mesial-distal directions was higher than males' (P<0.05). The Y of buccal root canals in buccal-lingual directions and mesial-distal directions and the CCA of lingual root canals in buccal-lingual directions between male and female had statistical differences (P<0.05). The CAA of curved buccal canals and curved palatal canals from female and female had positive correlation with CCA and X (P<0.01), while negative correlation with Y (P<0.05).</p><p><b>CONCLUSION</b>There are curved root canals in buccal-lingual and mesial-distal directions in the maxillary first premolars, and some curved root canals were S-shaped. The curved canals incidence rate of females was higher than males.</p>