ABSTRACT
Objective To investigate CTGF changes in the expression of the gum tissue before and after orthodontic treatment, and to preliminarily explore the modification mechanism of gingival tissue and the effectiveness of the intervention measures. Methods 72 male Sprague-Dawley rats of 12-week-old, weight about 250 g-300 g, randomly divided into 6 groups: blank control group (A), healthy teeth orthodontic group (B), low functional group (C), low occlusal function teeth orthodontic group (D), combined intervention group (E), bite orthodontic intervention group (F). The results of the study were compared at 1 w, 2 w, 4 w, 6 w.Results (1) HE staining results showed the atrophy of the gingival tissue, which suggested that occlusal hypofunction SD rats model were successfully established. (2) Fluorescence quantitative results of CTGF in gingival tissue: 6 w: group B was higher than group D and group F (P＜0.05). Conclusion (1) the expression of CTGF in the low occlusion group was lower than that of the normal control group with time, and the gum tissue was vulnerable to atrophy. (2) It remains to be further studied whether the bite force recovery is effective.
ABSTRACT
Objective To study local people's habits and customs concerning the prevention of dental fluorosis in an indoor coal-combustion-type fluorosis area of Zhaotong city Yunnan province, and to provide reference value for monitoring and control of the disease. Methods In 2008, 600 people of a 12-year-old group (400 people) and a 35 - 44-year-old group(200 people) were examined for dental fluorosis and oral health status in an indoor coal-combustion-type fluorosis area of Zhaotong. A questionnaire survey of 120 students and 60 adults was carried out on their habits and customs, stove changing status, knowledge of prevention of dental fluorosis, social psychology status, oral health behavior and their need for medical treatment. Results The total prevalence of dental fluorosis was 91.0% (546/600), dental fluorosis index was 2.58. The total prevalence of dental fluorosis of 12-year-old group was 86.5%(346/400), and dental fluorosis index was 2.12. The total prevalence of dental fluorosis of rural student was 90.5% (181/200), which was obviously higher in the rural group than the urban group [82.5% (165/200), χ2 = 5.48, P < 0.05]. The total prevalence of dental fluorosis of 35-44-year-old group was 100% (200/200), which was obviously higher than that of the 12-year-old group(χ2 = 29.67, P < 0.01). The rates of using coal, baking of food, changing stoves were 66.7% (60/90), 14.4% (13/90),57.8% (52/90), respectively, and these values of the urban were much lower than those of the rural[95.6%(86/90) ,31.1%(28/90) ,76.7%(69/90),χ2 = 24.51,7.11,7.29, all P < 0.01]. Only 23.3% (42/180) of people surveied had the knowledge of prevention of dental fluorosis, and the rate in the adult group[56.7% (34/60)]was higher than that of the student group [6.7% (8/120), χ2 = 55.9, P < 0.01]. The same rate in the urban student group was 0(0/60), and the rural student group was 13.3%(8/60), there was a significant difference between them(χ2 = 5.66, P < 0.05). Seventy-three point nine per cent( 133/180) of these people thought dental fluorosis had significant effect on their life, 91.1%(164/180) of these 'people wished to be treated. Eighty-four point four per cent( 152/180) of the people had a habit of toothbrushing,and 50.7% (77/152) of these people were still using toothpaste containing fluorine. Conclusions Zhaotong is a serious indoor coal-combustion-type fluorosis area. Enhancing health education to local people especially to students, and changing people's unhealthy habits and customs are keies to control the prevalence of indoor coal-combustion-type dental fluorosis.
ABSTRACT
<p><b>OBJECTIVE</b>To develop a best chitosan film for using as a drug sustained-release system through the evaluation of the sustained-release property, degradation property, and cytotoxicity to osteoblast.</p><p><b>METHODS</b>Orthogonal experiments were designed to determine the best combination of chitosan film preparations. Drug release rate was determined with Coomassie brilliant blue G250. In a separate study, chitosan films were placed into the test tubes with buffer solution and 10(7) U/L lysozyme. The degradation rate was calculated. Osteoblasts derived from fetal rat calvarial were cultured on chitosan films. Cell proliferation was tested by methyl thiazolyl tetrazolium (MTT) assay. The relative growth rate was calculated and the cytotoxicity was graded.</p><p><b>RESULTS</b>The best processing condition was 1% acetic acid, chitosan concentration of 2 mg/mL, 6% sodium tripolyphosphate (STPP) concentration, and cross-linking time of one hour. The resulting chitosan film released 33.13% of bovine serum albumin (BSA) within 8 d, 36.73% of BSA within four weeks and the cytotoxicity grade was 0 or 1.</p><p><b>CONCLUSION</b>This chitosan film possesses good sustained release property, and a good degradation rate.</p>