Laboratory interproximal access efficacy and gingival margin cleaning of the elmex SENSITIVE SOFT, EXTRA SOFT and ADA reference toothbrushes

OBJECTIVE: The purpose of these laboratory studies was to evaluate three toothbrushes for their ability to remove artificial plaque deposits at interproximal sites and along the gingival margin of simulated anterior and posterior teeth, using horizontal and vertical brushing motions. METHODOLOGY: Three toothbrushes were evaluated: elmex SENSITIVE SOFT; elmex SENSITIVE EXTRA SOFT; and the ADA reference. Twenty-four tests on each toothbrush group were conducted, and results were statistically analyzed using ANOVA and the post hoc Tukey test. RESULTS: In both the interproximal access efficacy and gingival margin cleaning assays, the elmex SENSITIVE EXTRA SOFT and SENSITIVE SOFT toothbrushes were statistically superior (p < 0.001) to the ADA reference toothbrush. CONCLUSION: The elmex SENSITIVE SOFT and EXTRA SOFT toothbrushes are predicted to offer excellent plaque removal efficacy interproximal areas and along the gingival margin of both anterior and posterior teeth.     

Laboratory assessment of the Sensodyne Mikro Aktiv extra soft toothbrush and the Oral-B indicator soft toothbrush

OBJECTIVE: The objective of this laboratory study was to assess the Sensodyne Mikro Aktiv extra soft toothbrush, compared with the Oral-B Indicator soft toothbrush, for interproximal access efficacy (IAE). METHODS: Six toothbrushes of each product were tested four times, for a total of twenty-four tests on each toothbrush design. In the IAE assay, the tooth brushing technique involved independent evaluations of each toothbrush in a vertical or horizontal brushing motion, tooth shapes simulating anterior and posterior teeth, and a brushing weight of 250 g. The brushing apparatus was set to brush for 15 seconds at two strokes per second with a 50 mm stroke. All readings were measured with 3x magnification by a single investigator. RESULTS: The mean IAE value on anterior tooth shapes, with vertical and horizontal brushing, was significantly (p < 0.001) higher for the Sensodyne Mikro Aktiv toothbrush than for the Oral-B Indicator toothbrush. When the IAE values were combined to give an overall brushing average, the Sensodyne Mikro Aktiv toothbrush was significantly (p < 0.001) higher compared to the Oral-B Indicator toothbrush. CONCLUSION: The Sensodyne Mikro Aktiv toothbrush has demonstrated superiority to the Oral-B Indicator toothbrush for access into interproximal areas using this laboratory methodology.     

Microbial complexes in supragingival plaque

Background/aims:  To examine microbial communities in supragingival biofilm samples.
Methods:  Supragingival plaque samples were taken from 187 subjects at baseline ( n  = 4745). Fifty-five subjects provided supragingival plaque samples at 1–7 days after professional tooth cleaning ( n  = 1456); 93 subjects provided 8044 samples between 3 and 24 months post-therapy. All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA–DNA hybridization. Microbial associations among species were sought using cluster analysis and community ordination techniques for the three groups separately.
Results:  Six complexes were formed for the baseline samples. Similar complexes were formed for the samples taken 3–24 months post-therapy. However, distinct changes were observed in microbial communities in samples taken during the 7 days of plaque redevelopment. The complexes related to clinical parameters of periodontal disease.
Conclusion:  There were specific microbial complexes in supragingival plaque that were similar to those found in subgingival plaque samples with a few minor differences. The relation of previously unclustered taxa to the complexes was also described.     

Scanning electron microscopic and energy dispersive x-ray evaluation of two smear layer-mediated dentinal bonding agents

Teeth treated with smear layer-mediated dentinal bonding agents and restored with composite resin were examined at the dentin-restoration interface by means of scanning electron microscopy used in conjunction with energy dispersive x-ray analysis. Results indicated that these dentinal bonding agents actually bonded to the smear layer, and samples demonstrated delamination of the smear layer from underlying dentin following thermocycling. This finding suggests that the stresses developed within the composite resin exceeded the adhesive strength of the smear layer to dentin. Thus, the bond strength for dentinal bonding agents that require the presence of the smear layer cannot exceed the adhesion of the smear layer to dentin.     

A comparison of enamelin and amelogenin expression in developing mouse molars

Amelogenin and enamelin are structural proteins in the enamel matrix of developing teeth. The temporal and spatial patterns of enamelin expression in developing mouse molars have not been characterized, while controversy remains with respect to amelogenin expression by odontoblasts and cementoblasts. Here we report the results of in situ hybridization analyses of amelogenin and enamelin expression in mouse molars from postnatal days 1, 2, 3, 7, 9, 14, and 21. Amelogenin and enamelin mRNA in maxillary first molars was first observed in pre-ameloblasts on the cusp slopes at day 2. The onsets of amelogenin and enamelin expression were approximately synchronous with the initial accumulation of predentin matrix. Both proteins were expressed by ameloblasts throughout the secretory, transition, and early maturation stages. Enamelin expression terminated in maturation stage ameloblasts on day 9, while amelogenin expression is still detected in maturation stage ameloblasts on day 14. No amelogenin expression was observed in day 21 mouse molars. Amelogenin and enamelin RNA messages were restricted to ameloblasts. No expression was observed in pulp, bone, or along the developing root. We conclude that amelogenin and enamelin are enamel-specific and do not directly participate in the formation of dentin or cementum in developing mouse molars.     

Inverted U-Shaped Associations between Glycemic Indices and Serum Uric Acid Levels in the General Chinese Population: Findings from the China Cardiometabolic Disease and Cancer Cohort (4C) Study

Objective The relationship between serum uric acid(SUA)levels and glycemic indices,including plasma glucose(FPG),2-hour postload glucose(2 h-PG),and glycated hemoglobin(HbA1 c),remains inconclusive.We aimed to explore the associations between glycemic indices and SUA levels in the general Chinese population.Methods The current study was a cross-sectional analysis using the first follow-up survey data from The China Cardiometabolic Disease and Cancer Cohort Study.A total of 105,922 community-dwelling adults aged≥40 years underwent the oral glucose tolerance test and uric acid assessment.The nonlinear relationships between glycemic indices and SUA levels were explored using generalized additive models.Results A total of 30,941 men and 62,361 women were eligible for the current analysis.Generalized additive models verified the inverted U-shaped association between glycemic indices and SUA levels,but with different inflection points in men and women.The thresholds for FPG,2 h-PG,and HbA1 c for men and women were 6.5/8.0 mmol/L,11.0/14.0 mmol/L,and 6.1/6.5,respectively(SUA levels increased with increasing glycemic indices before the inflection points and then eventually decreased with further increases in the glycemic indices).Conclusion An inverted U-shaped association was observed between major glycemic indices and uric acid levels in both sexes,while the inflection points were reached earlier in men than in women.     

许芝银调治气阴亏虚型石瘿

石瘿,西医病名甲状腺恶性肿瘤,目前是临床上最常见的头颈部恶性肿瘤类型之一,甲状腺癌术后常出现各种并发症.许芝银教授认为,石瘿术后常表现出气阴亏虚的证型,治疗以益气养阴为根本治法,同时注重调和肺脾肾,维持脏腑功能正常运行,术后短期使用全蝎清除余邪,术后长期使用西洋参补气扶正,同时对抗左甲状腺素钠片的副作用.     

Association between cannabis and the eyelids: A comprehensive review

Cannabis is the most consumed illicit drug worldwide. As more countries consider bills that would legalize adult use of cannabis, health care providers, including eye care professionals (ophthalmologists, optometrists), will need to recognize ocular effects of cannabis consumption in patients. There are only 20 studies on the eyelid effects of cannabis usage as a medical treatment or a recreational drug. These include ptosis induction, an “eyelid tremor” appearance and blepharospasm attenuation. Six articles describe how adequately dosed cannabis regimens could be promising medical treatments for blepharospasm induced by psychogenic factors. Fourteen articles report eyelid tremors in intoxicated drivers and ptosis as a secondary effect in cannabinoid animal experimental models. The exact mechanism of cannabinoids connecting cannabis to the eyelids is unclear. Further studies should be conducted to better understand the cannabinoid system in relation to the eyelid and eventually develop new, effective and safe therapeutic targets derived from cannabis.     

The involvement of central noradrenergic systems and corticotropin-releasing factor in defensive-withdrawal behavior in rats

The role of the central noradrenergic systems and corticotropin-releasing factor (CRF) in modulating defensive withdrawal behavior was studied in rats. The apparatus consisted of a small chamber set on one side of a one-meter open field, into which the rat was placed to start the test. When rats were unfamiliar with the apparatus, they displayed species typical defensive withdrawal behavior with long latencies to emerge from and a high proportion of time spent in the small chamber. Intraperitoneal administration of clonidine (0.03 mg/kg), l-propranolol (2.5 micrograms/kg), prazosin (0.1 mg/kg) or chlordiazepoxide (CDP, 5 mg/kg) each significantly decreased the latency to emerge from and the mean time spent in the small chamber (MTIC) and increased the number of chamber entries. When rats were familiar with the apparatus, prior restraint for 20 min significantly increased the latency and MTIC, and decreased the number of chamber entries and rears, but did not alter locomotor activity. Prazosin, clonidine, CDP, l-propranolol and the CRF-antagonist, alpha-helical CRF9-41 (25 micrograms i.c.v.), reversed the restraint-induced increase in the latency and MTIC. CRF (10-100 ng i.c.v.) dose-dependently induced defensive withdrawal behavior in rats familiar with the apparatus; the minimum statistically significant dose was 50 ng. dl-Propranolol (5 mg/kg) and CDP blocked the CRF-induced changes in the latency to emerge and the MTIC; whereas clonidine and prazosin significantly reduced the latency, but had no statistically significant effects on the MTIC. Phenylephrine (25-200 ng i.c.v.) dose-dependently induced defensive withdrawal behavior. This effect of phenylephrine (200 ng) was significantly antagonized by prazosin or alpha-helical CRF9-41 (25 or 50 mg i.c.v.), but not by CDP. Our results suggest that the hyperactivity of the central noradrenergic systems caused by exposure to the novel environment may stimulate the release of CRF, which through some unknown mechanism induces defensive withdrawal behavior in rats. Activation of beta adrenergic receptors may also induce defensive withdrawal.