Locally applied isosorbide decreases bone resorption in experimental periodontitis in rats

BACKGROUND: The role of nitric oxide (NO) on bone metabolism is controversial, since it can either stimulate bone formation or resorption. We investigated the effect of local administration of the NO donor isosorbide in an experimental periodontal disease model. METHODS: Wistar rats were subjected to a ligature placement around the cervix of the right second upper molar and were sacrificed after 11 days. Alveolar bone loss was measured in one quadrant as the sum of the distances between the cuspid tip and the alveolar bone along the axis of each molar root, which was subtracted from the contralateral side, used as unligated control. The semiquantitative histopathological scale of the periodontium was based on cell infiltration and alveolar bone and cementum integrity. Groups were treated with a gel containing 1% or 5% isosorbide applied to the vestibular side of the molar gingiva 1 hour before the placement of the ligature and then twice daily until sacrifice. Controls included one group subjected to periodontitis and no treatment (NT) and another that received the gel containing just the vehicle (V). RESULTS: The application of the vehicle gel produced an increase of the alveolar bone resorption, without altering the inflammatory changes, compared to the NT group. The 5% isosorbide produced a significant reduction of the alveolar bone resorption, compared to V and NT. This reduction was confirmed by histological analysis, showing less inflammatory cell infiltration and preservation of the cementum and the alveolar process. CONCLUSION: Local application of isosorbide reduces alveolar bone resorption in experimental periodontal disease in rats, suggesting a local anti-inflammatory effect of isosorbide.     

Assessing treatment effectiveness of removable and fixed orthodontic appliances with the occlusal index

Orthodontists from different backgrounds may have different opinions about removable and fixed orthodontic appliances, but there have been few objective comparisons of their relative treatment effectiveness. It is the purpose of the present study to analyze objectively the effectiveness of these two types of appliances. Eighty cases involving patients who had been treated with removable appliances and 67 cases of patients treated with fixed appliances were studied with respect to the Occlusal Index (OI). Scores indicating severity of malocclusion were obtained from pretreatment and posttreatment study casts. The effectiveness of the fixed appliance (represented by average reduction in OI score) was much greater than that of the removable appliance. The result of treatment with the fixed appliance was also found to be much better than that of the treatment with the removable appliance (indicated by the much lower posttreatment OI score in the fixed-appliance cases). The Occlusal Index was designed to measure features of basic malocclusion and is not a very sensitive index for assessing symptoms of a developing malocclusion. The fact that both the treatment effectiveness and the treatment results of the removable appliance were found to be inferior to those of the fixed appliance may indicate that the removable appliance has been used largely to correct "symptoms" rather than basic malocclusion.     

The effect of mineral trioxide aggregate on phagocytic activity and production of reactive oxygen, nitrogen species and arginase activity by M1 and M2 macrophages

AIM: To assess the influence of co-culture with mineral trioxide aggregate (MTA) on phagocytosis and the production of reactive oxygen intermediates (ROI) and nitrogen (NO) species and the arginase activity by M1 and M2 peritoneal macrophages. METHODOLOGY: Cellular viability, adherence and phagocytosis of Saccharomyces boulardii were assayed in the presence of MTA. Macrophages were stimulated with zymosan for ROI assays and with Fusobacterium nucleatum and Peptostreptococcus anaerobius and IFN-gamma for NO production and arginase activity, when in contact with capillaries containing MTA. Data were analysed by T, anova, Kruskall-Wallis and Mann-Whitney tests. RESULTS: M2 macrophages displayed greater cellular viability in polypropylene tubes, greater ability to ingest yeast and smaller production of ROI and higher arginase activity when compared with M1 macrophages. Both macrophages, M1 and M2, presented similar cell adherence and NO production. The addition of bacterial preparations to macrophages interfered with NO and arginase productions. MTA did not interfere with any of the parameters measured. CONCLUSIONS: Phagocytosis and the ability of the two macrophage subtypes to eliminate microbes were not affected by MTA.     

口腔扁平苔藓与慢性胃炎关系的临床研究

目的 探讨口腔扁平苔蓟与慢性胃炎的关系。方法 对１２６例扁平苔蓟患者进行上消化道内镜检查与胃粘膜活检。结果 １２２例口腔扁平苔蓟患者有不同类型慢性胃炎，患病率为９６．８％，显著高于人群普查资料（Ｐ〈０．０１）；扁平苔蓟损害类型与胃炎的严重程度有关（Ｐ〈０．０１）；对口腔扁平苔蓟所伴发的慢性胃炎进行治疗后，口腔损害取得改善，总有效率８６．９％，优于氯喹、强的松等传统治疗方法。结论 口腔扁平苔蓟与慢性     

A scanning electron microscopic study of the contraction of vascular wall cells in dog dental pulp

Ultrastructural changes in vascular wall cells in dog dental pulp after removal of connective tissue components were studied by scanning electron microscopy following administration of norepinephrine (0.2 mg/kg). Contracted smooth-muscle cells were frequently seen in arterioles of all sizes. The surfaces of these cells were highly irregular with numerous evaginations and invaginations, varying considerably in configuration and size. Many evaginations ran longitudinally or obliquely to the long axis of the vessel. Some meandering evaginations were also observed as, rarely, were small spherical or bulbous projections. Spidery smooth-muscle cells frequently seen in the tunica media of terminal arterioles and thought to be primitive smooth-muscle cells exhibited fewer irregularities than the typical spindle-shaped smooth-muscle cells beneath them. Pericytes in the larger post-capillary venules (20 microns or larger in diameter) often showed evaginations and invaginations, mainly running parallel to the vessel axis. On the other hand, no surface irregularities could be seen in pericytes of either the smaller post-capillary venules (less than 20 microns in diameter) or the capillaries, although occasional evaginations running parallel to the vessel axis were noted on the outer surface of the endothelium.     

Association of vitamin D receptor gene polymorphisms in Chinese patients with generalized aggressive periodontitis

Background and Objective:  The clinical features suggest that genetic factors may have a strong influence on susceptibility to aggressive periodontitis. The aim of this study was to investigate the association of vitamin D receptor gene polymorphisms with generalized aggressive periodontitis in Chinese patients.
Material and Methods:  A restriction fragment length polymorphism (RFLP) for 10,438,141 C to T (rs1544410, Bsm I), 10,382,063 A to G (rs731236, Taq I), 10,382,143 C to A (rs7975232, Apa I) and 10,416,201 A to G (rs2228570, Fok I) of vitamin D receptor gene was analysed by polymerase chain reaction, followed by digestion with restriction enzymes and gel electrophoresis. The genotypes of 51 generalized aggressive periodontitis patients and 53 periodontally healthy control subjects were analysed. The genotypic and allelic frequencies of each polymorphism site for the patients and control subjects were compared.
Results:  The distribution of vitamin D receptor Fok I genotypes and alleles between the two groups was significantly different ( p =  0.043 and p  = 0.012, respectively). The F allele seemed to increase the susceptibility of aggressive periodontitis (odds ratio = 2.02, 95% confidence interval = 1.16–3.50) in Chinese patients. There was no significant difference in the genotype distribution or the allele frequencies of vitamin D receptor Bsm I, Apa I and Taq I between two groups.
Conclusion:  The study indicates that Fok I polymorphism of vitamin D receptor gene might be associated with generalized aggressive periodontitis in Chinese patients. In addition, the carriage of F allele increases the risk of developing generalized aggressive periodontitis.     

Dental caries and microbial acid production in twins

OBJECTIVE: To determine the relative contribution of genetic and environmental stimuli on dental caries traits and microbial acid production in a twin model. METHODS: Dental caries examinations and microbial acid production assays were performed on 388 pairs of twins 1.5-8 years old from the city of Montes Claros, Brazil. Genotyping 8 polymorphic DNA markers determined zygosity. Caries exams followed NIDCR criteria modified to distinguish white spot lesions from cavitated lesions. Surface-based caries prevalence rates (SBCPR) were computed and lesion severity was determined by a weighted index (LSI). Biofilm samples were collected from the tongue using a lactic acid indicator swab. Assay scores were categorized based on acid formation as 1 = low, 2 = medium, and 3 = high. Heritability analyses were performed using the SOLAR software package. RESULTS: Heritability estimates for SBCPRs, LSI and for microbial acid production were H = 76.3 (p < 0.001), H = 70.6 (p < 0.001), H = 16.2 (p = 0.0078), respectively. Treating microbial acid production as a covariate in the SBCPR and LSI models did not significantly alter the heritability estimates, i.e. H = 76.5 (p < 0.001) and H = 70.8 (p < 0.001), respectively. CONCLUSIONS: These results suggest that variation in dental caries surface traits has a significant genetic contribution and that microbial acid production is modulated by the environment.     

颞颌关节镜治疗不同类型内错乱疗效的研究

为评价颞颌关节镜治疗不同类型内错乱的疗效，人进行８１例次关节手术。内错乱分期：Ⅱ期（早中期）２５例，Ⅲ期（中期）１８例，Ⅳ期（中晚期）２４例，Ⅴ期（晚期）１４例，中位随访期３．２年（０．５－７年），总有效率７４％（６０／８１）。内错乱分期与有效率的关系：Ⅱ期２４／２５，Ⅲ期１６／１８，Ⅳ期１３／２４，Ⅴ期７／１４。经统计学处理：Ⅱ、Ⅲ期之间及Ⅳ、Ⅴ期之间无显著性差异（Ｐ〉０．０５）；Ⅱ、Ⅲ期与Ⅳ、     

姜黄素对口腔舌癌细胞增殖与转移能力影响的实验研究

目的 探讨姜黄素对口腔舌癌细胞增殖与转移能力的作用及其作用机制.方法分别以0、5、10、20、30、60、100μmol·L-1姜黄素处理人舌癌细胞SCC-4 24 h,采用MTT法、侵袭实验、流式细胞仪、免疫荧光显微镜分别检测姜黄素对口腔舌癌细胞增殖与转移能力的影响.然后,采用cDNA微陈列芯片技术筛选和实时定鼍RT...